From 18ad0a04b64aeb239c348e64a238b66f6895d81e Mon Sep 17 00:00:00 2001
From: kalmar <kalmar@amu.edu.pl>
Date: Thu, 6 Jul 2017 09:18:53 +0200
Subject: [PATCH] replace_all! returns if any modification has been performed

---
 src/Groups.jl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Groups.jl b/src/Groups.jl
index 4b3339b..2d0aae2 100644
--- a/src/Groups.jl
+++ b/src/Groups.jl
@@ -352,15 +352,17 @@ function replace(W::GWord, index, toreplace::GWord, replacement::GWord)
 end
 
 function replace_all!{T}(W::GWord{T}, subst_dict::Dict{GWord{T}, GWord{T}})
+    modified = false
     for toreplace in reverse!(sort!(collect(keys(subst_dict)), by=length))
         replacement = subst_dict[toreplace]
         i = findfirst(W, toreplace)
         while i ≠ 0
+            modified = true
             replace!(W,i,toreplace, replacement)
             i = findnext(W, toreplace, i)
         end
     end
-    return W
+    return modified
 end
 
 replace_all{T<:GSymbol}(W::GWord{T}, subst_dict::Dict{GWord{T}, GWord{T}}) = replace_all!(deepcopy(W), subst_dict)