Jackson serialization for GREL functions

main/src/com/google/refine/expr/functions/Coalesce.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -60,13 +57,19 @@ public class Coalesce implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-    
-        writer.object();
-        writer.key("description"); writer.value("Returns the first non-null from a series of values");
-        writer.key("params"); writer.value("two or more objects");
-        writer.key("returns"); writer.value("object or null");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the first non-null from a series of values";
     }
+    
+    @Override
+    public String getParams() {
+        return "two or more objects";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "object or null";
+    }
+  
+    			
 }

main/src/com/google/refine/expr/functions/Cross.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.InterProjectModel.ProjectJoin;
 import com.google.refine.ProjectManager;
 import com.google.refine.expr.EvalError;
@@ -78,13 +75,17 @@ public class Cross implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "join with another project by column";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("join with another project by column");
-        writer.key("params"); writer.value("cell c or string value, string projectName, string columnName");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "cell c or string value, string projectName, string columnName";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/FacetCount.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.browsing.Engine;
 import com.google.refine.browsing.util.ExpressionNominalValueGrouper;
 import com.google.refine.expr.EvalError;
@@ -87,13 +84,17 @@ public class FacetCount implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the facet count corresponding to the given choice value";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the facet count corresponding to the given choice value");
-        writer.key("params"); writer.value("choiceValue, string facetExpression, string columnName");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "choiceValue, string facetExpression, string columnName";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/Get.java

@@ -39,7 +39,6 @@ import java.util.Properties;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.ExpressionUtils;
 import com.google.refine.expr.HasFields;
@@ -166,17 +165,21 @@ public class Get implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-    
-        writer.object();
-        writer.key("description"); writer.value(
+    public String getDescription() {
+        return 
             "If o has fields, returns the field named 'from' of o. " +
             "If o is an array, returns o[from, to]. " +
             "if o is a string, returns o.substring(from, to)"
-        );
-        writer.key("params"); writer.value("o, number or string from, optional number to");
-        writer.key("returns"); writer.value("Depends on actual arguments");
-        writer.endObject();
+        ;
+    }
+    
+    @Override
+    public String getParams() {
+        return "o, number or string from, optional number to";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "Depends on actual arguments";
     }
 }

main/src/com/google/refine/expr/functions/HasField.java

@@ -37,7 +37,6 @@ import java.util.Properties;
 
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.HasFields;
 import com.google.refine.grel.Function;
@@ -67,13 +66,17 @@ public class HasField implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns whether o has field name";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns whether o has field name");
-        writer.key("params"); writer.value("o, string name");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "o, string name";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/Jsonize.java

@@ -40,7 +40,6 @@ import java.util.Properties;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
-import org.json.JSONWriter;
 
 import com.google.refine.grel.Function;
 
@@ -79,13 +78,17 @@ public class Jsonize implements Function {
 
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Quotes a value as a JSON literal value";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Quotes a value as a JSON literal value");
-        writer.key("params"); writer.value("value");
-        writer.key("returns"); writer.value("JSON literal value");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "value";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "JSON literal value";
     }
 }

main/src/com/google/refine/expr/functions/Length.java

@@ -37,8 +37,6 @@ import java.util.Collection;
 import java.util.Properties;
 
 import org.json.JSONArray;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.HasFieldsList;
@@ -72,13 +70,17 @@ public class Length implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the length of o";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the length of o");
-        writer.key("params"); writer.value("array or string o");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array or string o";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/Slice.java

@@ -38,7 +38,6 @@ import java.util.Properties;
 
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.ExpressionUtils;
 import com.google.refine.expr.HasFieldsList;
@@ -130,16 +129,20 @@ public class Slice implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-    
-        writer.object();
-        writer.key("description"); writer.value(
+    public String getDescription() {
+        return 
             "If o is an array, returns o[from, to]. " +
             "if o is a string, returns o.substring(from, to)"
-        );
-        writer.key("params"); writer.value("o, number from, optional number to");
-        writer.key("returns"); writer.value("Depends on actual arguments");
-        writer.endObject();
+        ;
+    }
+    
+    @Override
+    public String getParams() {
+        return "o, number from, optional number to";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "Depends on actual arguments";
     }
 }

main/src/com/google/refine/expr/functions/ToDate.java

@@ -46,12 +46,10 @@ import java.util.Properties;
 import java.util.TimeZone;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
-import com.google.refine.expr.util.CalendarParserException;
 import com.google.refine.expr.util.CalendarParser;
+import com.google.refine.expr.util.CalendarParserException;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
 import com.google.refine.util.ParsingUtilities;
@@ -188,13 +186,17 @@ public class ToDate implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-    throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns o converted to a date object, you can hint if the day or the month is listed first, or give an ordered list of possible formats using this syntax: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html");
-        writer.key("params"); writer.value("o, boolean month_first / format1, format2, ... (all optional)");
-        writer.key("returns"); writer.value("date");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns o converted to a date object, you can hint if the day or the month is listed first, or give an ordered list of possible formats using this syntax: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html";
+    }
+    
+    @Override
+    public String getParams() {
+        return "o, boolean month_first / format1, format2, ... (all optional)";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "date";
     }
 }

main/src/com/google/refine/expr/functions/ToNumber.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -71,14 +68,18 @@ public class ToNumber implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns o converted to a number";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns o converted to a number");
-        writer.key("params"); writer.value("o");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "o";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 
 }

main/src/com/google/refine/expr/functions/ToString.java

@@ -37,9 +37,6 @@ import java.time.OffsetDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -72,13 +69,17 @@ public class ToString implements Function {
 
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns o converted to a string";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns o converted to a string");
-        writer.key("params"); writer.value("o, string format (optional)");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "o, string format (optional)";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/Type.java

@@ -37,9 +37,6 @@ import java.time.OffsetDateTime;
 import java.util.List;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -72,13 +69,17 @@ public class Type implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the type of o";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the type of o");
-        writer.key("params"); writer.value("object o");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "object o";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/arrays/ArgsToArray.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.arrays;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class ArgsToArray implements Function {
@@ -48,13 +45,17 @@ public class ArgsToArray implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns all arguments passed to it as an array";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns all arguments passed to it as an array");
-        writer.key("params"); writer.value("a1, a2, ...");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "a1, a2, ...";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/arrays/Join.java

@@ -38,7 +38,6 @@ import java.util.Properties;
 
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.ExpressionUtils;
@@ -101,13 +100,17 @@ public class Join implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the string obtained by joining the array a with the separator sep";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the string obtained by joining the array a with the separator sep");
-        writer.key("params"); writer.value("array a, string sep");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array a, string sep";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/arrays/Reverse.java

@@ -38,7 +38,6 @@ import java.util.Properties;
 
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.ExpressionUtils;
@@ -88,13 +87,17 @@ public class Reverse implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Reverses array a";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Reverses array a");
-        writer.key("params"); writer.value("array a");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array a";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/arrays/Sort.java

@@ -40,7 +40,6 @@ import java.util.Properties;
 
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -86,13 +85,17 @@ public class Sort implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Sorts array a";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Sorts array a");
-        writer.key("params"); writer.value("array a");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array a";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/arrays/Uniques.java

@@ -40,7 +40,6 @@ import java.util.Set;
 
 import org.json.JSONArray;
 import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.ExpressionUtils;
@@ -86,13 +85,17 @@ public class Uniques implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns array a with duplicates removed";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns array a with duplicates removed");
-        writer.key("params"); writer.value("array a");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array a";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/booleans/And.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.booleans;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class And implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-            throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("AND two or more booleans to yield a boolean");
-        writer.key("params"); writer.value("boolean a, boolean b");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    public String getDescription() {
+    	return "AND two or more booleans to yield a boolean";
+    }
+    
+    @Override
+    public String getParams() {
+        return "boolean a, boolean b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/booleans/Not.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.booleans;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class Not implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the opposite of b";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the opposite of b");
-        writer.key("params"); writer.value("boolean b");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "boolean b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/booleans/Or.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.booleans;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class Or implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("OR two or more booleans to yield a boolean");
-        writer.key("params"); writer.value("boolean a, boolean b");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    public String getDescription() {
+        return "OR two or more booleans to yield a boolean";
+    }
+    
+    @Override
+    public String getParams() {
+        return "boolean a, boolean b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/booleans/Xor.java

@@ -27,9 +27,6 @@ package com.google.refine.expr.functions.booleans;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -45,16 +42,17 @@ public class Xor implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-            throws JSONException {
-
-        writer.object();
-        writer.key("description");
-        writer.value("XORs two or more boolean values");
-        writer.key("params");
-        writer.value("boolean a, boolean b");
-        writer.key("returns");
-        writer.value("boolean");
-        writer.endObject();
+    public String getDescription() {
+    	return "XORs two or more boolean values";
+    }
+    
+    @Override
+    public String getParams() {
+        return "boolean a, boolean b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/date/DatePart.java

@@ -33,18 +33,15 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 package com.google.refine.expr.functions.date;
 
-import java.util.Calendar;
-import java.util.Date;
-import java.util.Properties;
-import java.util.TimeZone;
 import java.time.DayOfWeek;
 import java.time.LocalDate;
 import java.time.OffsetDateTime;
 import java.time.temporal.TemporalField;
 import java.time.temporal.WeekFields;
-
-import org.json.JSONException;
-import org.json.JSONWriter;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.Properties;
+import java.util.TimeZone;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -141,11 +138,17 @@ public class DatePart implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options) throws JSONException {
-        writer.object();
-        writer.key("description"); writer.value("Returns part of a date");
-        writer.key("params"); writer.value("date d, string part");
-        writer.key("returns"); writer.value("date");
-        writer.endObject();
+    public String getDescription() {
+    	return "Returns part of a date";
+    }
+    
+    @Override
+    public String getParams() {
+        return "date d, string part";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "date";
     }
 }

main/src/com/google/refine/expr/functions/date/Inc.java

@@ -38,9 +38,6 @@ import java.time.temporal.ChronoUnit;
 import java.time.temporal.TemporalUnit;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -88,11 +85,17 @@ public class Inc implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options) throws JSONException {
-        writer.object();
-        writer.key("description"); writer.value("Returns a date changed by the given amount in the given unit of time");
-        writer.key("params"); writer.value("date d, number value, string unit (default to 'hour')");
-        writer.key("returns"); writer.value("date");
-        writer.endObject();
+    public String getDescription() {
+    	return "Returns a date changed by the given amount in the given unit of time";
+    }
+    
+    @Override
+    public String getParams() {
+        return "date d, number value, string unit (default to 'hour')";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "date";
     }
 }

main/src/com/google/refine/expr/functions/date/Now.java

@@ -53,12 +53,12 @@ public class Now implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the current time";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the current time");
-        writer.key("returns"); writer.value("date");
-        writer.endObject();
+    @Override
+    public String getReturns() {
+        return "date";
     }
 }

main/src/com/google/refine/expr/functions/html/InnerHtml.java

@@ -35,8 +35,6 @@ package com.google.refine.expr.functions.html;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
 import org.jsoup.nodes.Element;
 
 import com.google.refine.expr.EvalError;
@@ -61,14 +59,18 @@ public class InnerHtml implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("The innerHtml of an HTML element");
-        writer.key("params"); writer.value("Element e");
-        writer.key("returns"); writer.value("String innerHtml");
-        writer.endObject();
+    public String getDescription() {
+        return "The innerHtml of an HTML element";
+    }
+    
+    @Override
+    public String getParams() {
+        return "Element e";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "String innerHtml";
     }
 }
 

main/src/com/google/refine/expr/functions/html/ParseHtml.java

@@ -35,8 +35,7 @@ package com.google.refine.expr.functions.html;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
+import org.jsoup.Jsoup;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.functions.xml.ParseXml;
@@ -58,14 +57,18 @@ public class ParseHtml implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Parses a string as HTML");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("HTML object");
-        writer.endObject();
+    public String getDescription() {
+        return "Parses a string as HTML";
+    }
+    
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "HTML object";
     }
 }
 

main/src/com/google/refine/expr/functions/math/ACos.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class ACos implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the arc cosine of an angle, in the range 0 through PI");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the arc cosine of an angle, in the range 0 through PI";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/ASin.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class ASin implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the arc sine of an angle in the range of -PI/2 through PI/2");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the arc sine of an angle in the range of -PI/2 through PI/2";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/ATan.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class ATan implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the arc tangent of an angle in the range of -PI/2 through PI/2");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the arc tangent of an angle in the range of -PI/2 through PI/2";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/ATan2.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -54,13 +51,17 @@ public class ATan2 implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Converts rectangular coordinates (x, y) to polar (r, theta)");
-        writer.key("params"); writer.value("number x, number y");
-        writer.key("returns"); writer.value("number theta");
-        writer.endObject();
+    public String getDescription() {
+        return "Converts rectangular coordinates (x, y) to polar (r, theta)";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number x, number y";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number theta";
     }
 }

main/src/com/google/refine/expr/functions/math/Abs.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Abs implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the absolute value of a number";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the absolute value of a number");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Ceil.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Ceil implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the ceiling of a number";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the ceiling of a number");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Combin.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -87,13 +84,17 @@ public class Combin implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the number of combinations for n elements as divided into k");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the number of combinations for n elements as divided into k";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Cos.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Cos implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the trigonometric cosine of an angle");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the trigonometric cosine of an angle";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Cosh.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Cosh implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the hyperbolic cosine of a value");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the hyperbolic cosine of a value";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Degrees.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Degrees implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Converts an angle from radians to degrees.");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Converts an angle from radians to degrees.";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Even.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class Even implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Rounds the number up to the nearest even integer");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Rounds the number up to the nearest even integer";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Exp.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class Exp implements Function {
@@ -51,13 +48,17 @@ public class Exp implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns e^n";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns e^n");
-        writer.key("params"); writer.value("number n");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Fact.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Fact implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the factorial of a number");
-        writer.key("params"); writer.value("number i");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the factorial of a number";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number i";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/FactN.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -80,13 +77,17 @@ public class FactN implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the factorial of a number");
-        writer.key("params"); writer.value("number i");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the factorial of a number";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number i";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Floor.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,14 +50,18 @@ public class Floor implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the floor of a number as an integer";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the floor of a number as an integer");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 
 }

main/src/com/google/refine/expr/functions/math/GreatestCommonDenominator.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class GreatestCommonDenominator implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the greatest common denominator of the two numbers");
-        writer.key("params"); writer.value("number d, number e");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the greatest common denominator of the two numbers";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d, number e";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/LeastCommonMultiple.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -70,13 +67,17 @@ public class LeastCommonMultiple implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the greatest common denominator of the two numbers");
-        writer.key("params"); writer.value("number d, number e");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the greatest common denominator of the two numbers";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d, number e";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Ln.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Ln implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the natural log of n";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the natural log of n");
-        writer.key("params"); writer.value("number n");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Log.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Log implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the base 10 log of n";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the base 10 log of n");
-        writer.key("params"); writer.value("number n");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Max.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -57,13 +54,17 @@ public class Max implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the greater of two numbers";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the greater of two numbers");
-        writer.key("params"); writer.value("number a, number b");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number a, number b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Min.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -57,13 +54,17 @@ public class Min implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the smaller of two numbers";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the smaller of two numbers");
-        writer.key("params"); writer.value("number a, number b");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number a, number b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Mod.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class Mod implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns a modulus b";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns a modulus b");
-        writer.key("params"); writer.value("number a, number b");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number a, number b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Multinomial.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -63,13 +60,17 @@ public class Multinomial implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Calculates the multinomial of a series of numbers");
-        writer.key("params"); writer.value("one or more numbers");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Calculates the multinomial of a series of numbers";
+    }
+    
+    @Override
+    public String getParams() {
+        return "one or more numbers";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Odd.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -58,13 +55,17 @@ public class Odd implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Rounds the number up to the nearest even integer");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Rounds the number up to the nearest even integer";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Pow.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class Pow implements Function {
@@ -54,13 +51,17 @@ public class Pow implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns a^b";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns a^b");
-        writer.key("params"); writer.value("number a, number b");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number a, number b";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Quotient.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -54,13 +51,17 @@ public class Quotient implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the integer portion of a division");
-        writer.key("params"); writer.value("number numerator, number denominator");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the integer portion of a division";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number numerator, number denominator";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Radians.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Radians implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Converts an angle in degrees to radians");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Converts an angle in degrees to radians";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Round.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Round implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns n rounded";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns n rounded");
-        writer.key("params"); writer.value("number n");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Sin.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Sin implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the trigonometric sine of an angle");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the trigonometric sine of an angle";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Sinh.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Sinh implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the hyperbolic sine of an angle");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the hyperbolic sine of an angle";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Sum.java

@@ -36,9 +36,6 @@ package com.google.refine.expr.functions.math;
 import java.util.List;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.ExpressionUtils;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -82,13 +79,17 @@ public class Sum implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Sums numbers in array a";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Sums numbers in array a");
-        writer.key("params"); writer.value("array a");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "array a";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Tan.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Tan implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the trigonometric tangent of an angle");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the trigonometric tangent of an angle";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/math/Tanh.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.math;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -53,13 +50,17 @@ public class Tanh implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Returns the hyperbolic tangent of a value");
-        writer.key("params"); writer.value("number d");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    public String getDescription() {
+        return "Returns the hyperbolic tangent of a value";
+    }
+    
+    @Override
+    public String getParams() {
+        return "number d";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/strings/Chomp.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.grel.Function;
 
@@ -56,13 +54,17 @@ public class Chomp implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Removes separator from the end of str if it's there, otherwise leave it alone.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Removes separator from the end of str if it's there, otherwise leave it alone.");
-        writer.key("params"); writer.value("string str, string separator");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string str, string separator";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Contains.java

@@ -37,9 +37,6 @@ import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class Contains implements Function {
@@ -64,13 +61,17 @@ public class Contains implements Function {
         return null;
     }
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns whether s contains frag";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns whether s contains frag");
-        writer.key("params"); writer.value("string s, string frag");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string frag";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/strings/Diff.java

@@ -37,8 +37,6 @@ import java.time.OffsetDateTime;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.Function;
@@ -104,12 +102,18 @@ public class Diff implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options) throws JSONException {
-        writer.object();
-        writer.key("description"); writer.value("For strings, returns the portion where they differ. For dates, it returns the difference in given time units");
-        writer.key("params"); writer.value("o1, o2, time unit (optional)");
-        writer.key("returns"); writer.value("string for strings, number for dates");
-        writer.endObject();
+    public String getDescription() {
+    	return "For strings, returns the portion where they differ. For dates, it returns the difference in given time units";
+    }
+    
+    @Override
+    public String getParams() {
+        return "o1, o2, time unit (optional)";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string for strings, number for dates";
     }
     
     private long getNano(OffsetDateTime odt) {

main/src/com/google/refine/expr/functions/strings/EndsWith.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -57,13 +54,17 @@ public class EndsWith implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns whether s ends with sub";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns whether s ends with sub");
-        writer.key("params"); writer.value("string s, string sub");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string sub";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/strings/Escape.java

@@ -38,8 +38,6 @@ import java.net.URLEncoder;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringEscapeUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -85,13 +83,17 @@ public class Escape implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Escapes a string depending on the given escaping mode.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Escapes a string depending on the given escaping mode.");
-        writer.key("params"); writer.value("string s, string mode ['html','xml','csv','url','javascript']");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string mode ['html','xml','csv','url','javascript']";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Find.java

@@ -7,9 +7,6 @@ import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -41,13 +38,17 @@ public class Find implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns all the occurances of match given regular expression";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns all the occurances of match given regular expression");
-        writer.key("params"); writer.value("string or regexp");
-        writer.key("returns"); writer.value("array of strings");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string or regexp";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array of strings";
     }
 }

main/src/com/google/refine/expr/functions/strings/Fingerprint.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.clustering.binning.FingerprintKeyer;
 import com.google.refine.clustering.binning.Keyer;
 import com.google.refine.grel.Function;
@@ -57,13 +54,17 @@ public class Fingerprint implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the fingerprint of s, a derived string that aims to be a more canonical form of it (this is mostly useful for finding clusters of strings related to the same information).";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the fingerprint of s, a derived string that aims to be a more canonical form of it (this is mostly useful for finding clusters of strings related to the same information).");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/IndexOf.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -57,13 +54,17 @@ public class IndexOf implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the index of sub first ocurring in s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the index of sub first ocurring in s");
-        writer.key("params"); writer.value("string s, string sub");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string sub";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 }

main/src/com/google/refine/expr/functions/strings/LastIndexOf.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -57,14 +54,18 @@ public class LastIndexOf implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the index of sub last ocurring in s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the index of sub last ocurring in s");
-        writer.key("params"); writer.value("string s, string sub");
-        writer.key("returns"); writer.value("number");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string sub";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "number";
     }
 
 }

main/src/com/google/refine/expr/functions/strings/MD5.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.codec.digest.DigestUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -56,13 +54,17 @@ public class MD5 implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the MD5 hash of s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the MD5 hash of s");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Match.java

@@ -37,9 +37,6 @@ import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -78,13 +75,17 @@ public class Match implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns an array of the groups matching the given regular expression";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns an array of the groups matching the given regular expression");
-        writer.key("params"); writer.value("string or regexp");
-        writer.key("returns"); writer.value("array of strings");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string or regexp";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array of strings";
     }
 }

main/src/com/google/refine/expr/functions/strings/NGram.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -79,13 +77,17 @@ public class NGram implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns an array of the word ngrams of s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns an array of the word ngrams of s");
-        writer.key("params"); writer.value("string s, number n");
-        writer.key("returns"); writer.value("array of strings");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array of strings";
     }
 }

main/src/com/google/refine/expr/functions/strings/NGramFingerprint.java

@@ -36,9 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 import java.util.TreeSet;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.clustering.binning.Keyer;
 import com.google.refine.clustering.binning.NGramFingerprintKeyer;
 import com.google.refine.expr.EvalError;
@@ -76,13 +73,17 @@ public class NGramFingerprint implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the n-gram fingerprint of s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the n-gram fingerprint of s");
-        writer.key("params"); writer.value("string s, number n");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, number n";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/ParseJson.java

@@ -37,7 +37,6 @@ import java.util.Properties;
 
 import org.json.JSONException;
 import org.json.JSONTokener;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -62,13 +61,17 @@ public class ParseJson implements Function {
 
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Parses a string as JSON";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Parses a string as JSON");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("JSON object");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "JSON object";
     }
 }

main/src/com/google/refine/expr/functions/strings/Partition.java

@@ -37,9 +37,6 @@ import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class Partition implements Function {
@@ -101,14 +98,18 @@ public class Partition implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return 
+            "Returns an array of strings [a,frag,b] where a is the string part before the first occurrence of frag in s and b is what's left. If omitFragment is true, frag is not returned.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value(
-            "Returns an array of strings [a,frag,b] where a is the string part before the first occurrence of frag in s and b is what's left. If omitFragment is true, frag is not returned.");
-        writer.key("params"); writer.value("string s, string or regex frag, optional boolean omitFragment");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string or regex frag, optional boolean omitFragment";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/Phonetic.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.clustering.binning.ColognePhoneticKeyer;
 import com.google.refine.clustering.binning.DoubleMetaphoneKeyer;
 import com.google.refine.clustering.binning.Metaphone3Keyer;
@@ -100,13 +97,17 @@ public class Phonetic implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the a phonetic encoding of s (optionally indicating which encoding to use')";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the a phonetic encoding of s (optionally indicating which encoding to use')");
-        writer.key("params"); writer.value("string s, string encoding (optional, defaults to 'metaphone3')");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string encoding (optional, defaults to 'metaphone3')";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/RPartition.java

@@ -37,9 +37,6 @@ import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class RPartition implements Function {
@@ -102,14 +99,18 @@ public class RPartition implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return 
+            "Returns an array of strings [a,frag,b] where a is the string part before the last occurrence of frag in s and b is what's left. If omitFragment is true, frag is not returned.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value(
-            "Returns an array of strings [a,frag,b] where a is the string part before the last occurrence of frag in s and b is what's left. If omitFragment is true, frag is not returned.");
-        writer.key("params"); writer.value("string s, string or regex frag, optional boolean omitFragment");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string or regex frag, optional boolean omitFragment";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/Range.java

@@ -1,11 +1,8 @@
 package com.google.refine.expr.functions.strings;
 
+import java.util.Properties;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import java.util.Properties;
-
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -295,14 +292,18 @@ public class Range implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value(
-                "Returns an array where a and b are the start and the end of the range respectively and c is the step (increment).");
-        writer.key("params"); writer.value("A single string 'a', 'a, b' or 'a, b, c' or one, two or three integers a or a, b or a, b, c");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    public String getDescription() {
+        return 
+                "Returns an array where a and b are the start and the end of the range respectively and c is the step (increment).";
+    }
+    
+    @Override
+    public String getParams() {
+        return "A single string 'a', 'a, b' or 'a, b, c' or one, two or three integers a or a, b or a, b, c";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/Reinterpret.java

@@ -36,9 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.io.UnsupportedEncodingException;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.ProjectManager;
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -99,13 +96,17 @@ public class Reinterpret implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns s reinterpreted thru the given encoder.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns s reinterpreted thru the given encoder.");
-        writer.key("params"); writer.value("string s, string encoder");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string encoder";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Replace.java

@@ -36,9 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 import java.util.regex.Pattern;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -67,13 +64,17 @@ public class Replace implements Function {
 
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the string obtained by replacing f with r in s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the string obtained by replacing f with r in s");
-        writer.key("params"); writer.value("string s, string or regex f, string r");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string or regex f, string r";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/ReplaceChars.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -61,13 +59,17 @@ public class ReplaceChars implements Function {
 
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the string obtained by replacing all chars in f with the char in s at that same position";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the string obtained by replacing all chars in f with the char in s at that same position");
-        writer.key("params"); writer.value("string s, string f, string r");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string f, string r";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/SHA1.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.codec.digest.DigestUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -56,13 +54,17 @@ public class SHA1 implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the SHA-1 hash of s";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the SHA-1 hash of s");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/SmartSplit.java

@@ -36,15 +36,12 @@ package com.google.refine.expr.functions.strings;
 import java.io.IOException;
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
-import au.com.bytecode.opencsv.CSVParser;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
 
+import au.com.bytecode.opencsv.CSVParser;
+
 public class SmartSplit implements Function {
 
     static final protected CSVParser s_tabParser = new CSVParser(
@@ -104,13 +101,17 @@ public class SmartSplit implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the array of strings obtained by splitting s with separator sep. Handles quotes properly. Guesses tab or comma separator if \"sep\" is not given.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the array of strings obtained by splitting s with separator sep. Handles quotes properly. Guesses tab or comma separator if \"sep\" is not given.");
-        writer.key("params"); writer.value("string s, optional string sep");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, optional string sep";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/Split.java

@@ -37,8 +37,6 @@ import java.util.Properties;
 import java.util.regex.Pattern;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -76,13 +74,17 @@ public class Split implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the array of strings obtained by splitting s with separator sep. If preserveAllTokens is true, then empty segments are preserved.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the array of strings obtained by splitting s with separator sep. If preserveAllTokens is true, then empty segments are preserved.");
-        writer.key("params"); writer.value("string s, string or regex sep, optional boolean preserveAllTokens");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string or regex sep, optional boolean preserveAllTokens";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/SplitByCharType.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -58,13 +56,17 @@ public class SplitByCharType implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns an array of strings obtained by splitting s grouping consecutive chars by their unicode type";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns an array of strings obtained by splitting s grouping consecutive chars by their unicode type");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/SplitByLengths.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -71,13 +68,17 @@ public class SplitByLengths implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns the array of strings obtained by splitting s into substrings with the given lengths";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns the array of strings obtained by splitting s into substrings with the given lengths");
-        writer.key("params"); writer.value("string s, number n, ...");
-        writer.key("returns"); writer.value("array");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, number n, ...";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "array";
     }
 }

main/src/com/google/refine/expr/functions/strings/StartsWith.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -56,13 +53,17 @@ public class StartsWith implements Function {
         return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects 2 strings");
     }
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns whether s starts with sub";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns whether s starts with sub");
-        writer.key("params"); writer.value("string s, string sub");
-        writer.key("returns"); writer.value("boolean");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string sub";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "boolean";
     }
 }

main/src/com/google/refine/expr/functions/strings/ToLowercase.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -54,13 +51,17 @@ public class ToLowercase implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns s converted to lowercase";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns s converted to lowercase");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/ToTitlecase.java

@@ -36,8 +36,6 @@ package com.google.refine.expr.functions.strings;
 import java.util.Properties;
 
 import org.apache.commons.lang3.text.WordUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -64,14 +62,18 @@ public class ToTitlecase implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns s converted to titlecase";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns s converted to titlecase");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 
 }

main/src/com/google/refine/expr/functions/strings/ToUppercase.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
 import com.google.refine.grel.Function;
@@ -54,13 +51,17 @@ public class ToUppercase implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns s converted to uppercase";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns s converted to uppercase");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Trim.java

@@ -35,11 +35,7 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.common.base.CharMatcher;
-
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.Function;
 
@@ -56,13 +52,17 @@ public class Trim implements Function {
         return new EvalError("Invalid parameters");
     }
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns copy of the string, with leading and trailing whitespace omitted.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns copy of the string, with leading and trailing whitespace omitted.");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Unescape.java

@@ -38,8 +38,6 @@ import java.net.URLDecoder;
 import java.util.Properties;
 
 import org.apache.commons.lang3.StringEscapeUtils;
-import org.json.JSONException;
-import org.json.JSONWriter;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.grel.ControlFunctionRegistry;
@@ -76,13 +74,17 @@ public class Unescape implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Unescapes all escaped parts of the string depending on the given escaping mode.";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Unescapes all escaped parts of the string depending on the given escaping mode.");
-        writer.key("params"); writer.value("string s, string mode ['html','xml','csv','url','javascript']");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s, string mode ['html','xml','csv','url','javascript']";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/Unicode.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class Unicode implements Function {
@@ -57,13 +54,17 @@ public class Unicode implements Function {
     }
     
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns an array of strings describing each character of s in their full unicode notation";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns an array of strings describing each character of s in their full unicode notation");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/strings/UnicodeType.java

@@ -35,9 +35,6 @@ package com.google.refine.expr.functions.strings;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
-
 import com.google.refine.grel.Function;
 
 public class UnicodeType implements Function {
@@ -94,13 +91,17 @@ public class UnicodeType implements Function {
     }
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
+    public String getDescription() {
+        return "Returns an array of strings describing each character of s in their full unicode notation";
+    }
     
-        writer.object();
-        writer.key("description"); writer.value("Returns an array of strings describing each character of s in their full unicode notation");
-        writer.key("params"); writer.value("string s");
-        writer.key("returns"); writer.value("string");
-        writer.endObject();
+    @Override
+    public String getParams() {
+        return "string s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "string";
     }
 }

main/src/com/google/refine/expr/functions/xml/OwnText.java

@@ -35,8 +35,6 @@ package com.google.refine.expr.functions.xml;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
 import org.jsoup.nodes.Element;
 
 import com.google.refine.expr.EvalError;
@@ -62,14 +60,18 @@ public class OwnText implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Gets the text owned by this XML/HTML element only; does not get the combined text of all children.");
-        writer.key("params"); writer.value("Element e");
-        writer.key("returns"); writer.value("String ownText");
-        writer.endObject();
+    public String getDescription() {
+        return "Gets the text owned by this XML/HTML element only; does not get the combined text of all children.";
+    }
+    
+    @Override
+    public String getParams() {
+        return "Element e";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "String ownText";
     }
 }
 

main/src/com/google/refine/expr/functions/xml/SelectXml.java

@@ -35,8 +35,6 @@ package com.google.refine.expr.functions.xml;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
 import org.jsoup.nodes.Element;
 
 import com.google.refine.expr.EvalError;
@@ -64,14 +62,18 @@ public class SelectXml implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Selects an element from an XML or HTML element using selector syntax.");
-        writer.key("params"); writer.value("Element e, String s");
-        writer.key("returns"); writer.value("XML/HTML Elements");
-        writer.endObject();
+    public String getDescription() {
+        return "Selects an element from an XML or HTML elementn using selector syntax.";
+    }
+    
+    @Override
+    public String getParams() {
+        return "Element e, String s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "HTML Elements";
     }
 }
 

main/src/com/google/refine/expr/functions/xml/XmlAttr.java

@@ -35,8 +35,6 @@ package com.google.refine.expr.functions.xml;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
 import org.jsoup.nodes.Element;
 
 import com.google.refine.expr.EvalError;
@@ -64,14 +62,18 @@ public class XmlAttr implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Selects a value from an attribute on an xml or html Element.");
-        writer.key("params"); writer.value("Element e, String s");
-        writer.key("returns"); writer.value("String attribute Value");
-        writer.endObject();
+    public String getDescription() {
+        return "Selects a value from an attribute on an XML or HTML Element";
+    }
+    
+    @Override
+    public String getParams() {
+        return "Element e, String s";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "String attribute Value";
     }
 }
 

main/src/com/google/refine/expr/functions/xml/XmlText.java

@@ -35,8 +35,6 @@ package com.google.refine.expr.functions.xml;
 
 import java.util.Properties;
 
-import org.json.JSONException;
-import org.json.JSONWriter;
 import org.jsoup.nodes.Element;
 
 import com.google.refine.expr.EvalError;
@@ -62,14 +60,18 @@ public class XmlText implements Function {
 
 
     @Override
-    public void write(JSONWriter writer, Properties options)
-        throws JSONException {
-
-        writer.object();
-        writer.key("description"); writer.value("Selects the text from within an element (including all child elements)");
-        writer.key("params"); writer.value("Element e");
-        writer.key("returns"); writer.value("String text");
-        writer.endObject();
+    public String getDescription() {
+        return "Selects the text from within an element (including all child elements)";
+    }
+    
+    @Override
+    public String getParams() {
+        return "Element e";
+    }
+    
+    @Override
+    public String getReturns() {
+        return "String text";
     }
 }
 

main/src/com/google/refine/grel/Function.java

@@ -35,6 +35,11 @@ package com.google.refine.grel;
 
 import java.util.Properties;
 
+import org.json.JSONWriter;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.refine.Jsonizable;
 
 /**
@@ -43,4 +48,27 @@ import com.google.refine.Jsonizable;
  */
 public interface Function extends Jsonizable {
     public Object call(Properties bindings, Object[] args);
+    
+    @JsonProperty("description")
+    public String getDescription();
+    
+    @JsonProperty("params")
+    @JsonInclude(Include.NON_EMPTY)
+    default public String getParams() {
+    	return "";
+    }
+    
+    @JsonProperty("returns")
+    public String getReturns();
+    
+    @Override
+    default public void write(JSONWriter writer, Properties options) {
+    	writer.object();
+    	writer.key("description"); writer.value(getDescription());
+    	if (!getParams().isEmpty()) {
+    		writer.key("params"); writer.value(getParams());
+    	}
+    	writer.key("returns"); writer.value(getReturns());
+    	writer.endObject();
+    }
 }