Add coalesce function

This commit is contained in:
Owen Stephens 2018-03-07 09:10:11 +00:00
parent bce7f097dd
commit 01b96a0155
3 changed files with 178 additions and 0 deletions

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@ -0,0 +1,72 @@
/*
Copyright 2018, Owen Stephens
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
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;
public class Coalesce implements Function {
@Override
public Object call(Properties bindings, Object[] args) {
if (args.length> 0) {
for (int i = 0; i < args.length; i++){
if (args[i] == null) {
continue;
} else {
return args[i];
}
}
return null;
}
return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects at least one argument");
}
@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("one or more objects");
writer.key("returns"); writer.value("object");
writer.endObject();
}
}

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@ -38,6 +38,7 @@ import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import com.google.refine.expr.functions.Coalesce;
import com.google.refine.expr.functions.Cross;
import com.google.refine.expr.functions.FacetCount;
import com.google.refine.expr.functions.Get;
@ -186,6 +187,7 @@ public class ControlFunctionRegistry {
}
static {
registerFunction("coalesce", new Coalesce());
registerFunction("type", new Type());
registerFunction("toString", new ToString());

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@ -0,0 +1,104 @@
/*
Copyright 2011, Owen Stephens
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.google.refine.tests.expr.functions.strings;
import java.util.Properties;
import org.slf4j.LoggerFactory;
import org.testng.Assert;
import org.testng.annotations.AfterMethod;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.BeforeTest;
import org.testng.annotations.Test;
import com.google.refine.expr.EvalError;
import com.google.refine.grel.ControlFunctionRegistry;
import com.google.refine.grel.Function;
import com.google.refine.tests.RefineTest;
public class CoalesceTests extends RefineTest {
static Properties bindings;
private static final Integer[] ZERO_TO_TWO = new Integer[] {0, 1, 2};
@Override
@BeforeTest
public void init() {
logger = LoggerFactory.getLogger(this.getClass());
}
@BeforeMethod
public void SetUp() {
bindings = new Properties();
}
@AfterMethod
public void TearDown() {
bindings = null;
}
/**
* Lookup a control function by name and invoke it with a variable number of args
*/
private static Object invoke(String name,Object... args) {
// registry uses static initializer, so no need to set it up
Function function = ControlFunctionRegistry.getFunction(name);
if (function == null) {
throw new IllegalArgumentException("Unknown function "+name);
}
if (args == null) {
return function.call(bindings,new Object[0]);
} else {
return function.call(bindings,args);
}
}
@Test
public void testCoalesceInvalidParams() {
Assert.assertTrue(invoke("coalesce") instanceof EvalError);
}
@Test
public void testCoalesce() {
Assert.assertNull(invoke("coalesce", (Object) null));
Assert.assertEquals(invoke("coalesce", "string"),"string");
Assert.assertEquals(invoke("coalesce", 1),1);
Assert.assertEquals(invoke("coalesce", (Object) null, "string"),"string");
Assert.assertEquals(invoke("coalesce", (Object) null, (Object) null, "string"),"string");
Assert.assertEquals(invoke("coalesce", (Object) null, 1),1);
Assert.assertEquals(invoke("coalesce", (Object) null, ZERO_TO_TWO),ZERO_TO_TWO);
}
}