From e39b3d4f9b0666e822381c258ad3a1373a790fce Mon Sep 17 00:00:00 2001
From: Markus Pfeiffer <markus.pfeiffer@morphism.de>
Date: Thu, 13 Apr 2017 00:10:08 +0100
Subject: [PATCH] Add function LocationOfDeclaration

This function returns the location of the declaration of the passed
object if it is known.
---
 lib/type.gd | 18 ++++++++++++++++++
 lib/type.gi | 18 ++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/lib/type.gd b/lib/type.gd
index cd2634dfb8..072a245578 100644
--- a/lib/type.gd
+++ b/lib/type.gd
@@ -72,3 +72,21 @@ DeclareGlobalFunction( "IsCategory" );
 ##  </ManSection>
 ##  <#/GAPDoc>
 DeclareGlobalFunction( "CategoryByName" );
+
+
+#############################################################################
+##
+#F  LocationOfDeclaration( <object> )
+##
+##  Find the location of the declaration of <object>.
+##
+##  <#GAPDoc Label="LocationOfDeclaration">
+##  <ManSection>
+##  <Func Name="LocationofDeclaration" Arg='object'/>
+##
+##  <Description>
+##  returns the location of the declaration of <A>object</A> if it is known.
+##  </Description>
+##  </ManSection>
+##  <#/GAPDoc>
+DeclareGlobalFunction( "LocationOfDeclaration" );
diff --git a/lib/type.gi b/lib/type.gi
index fa8c53af2b..dc88738167 100644
--- a/lib/type.gi
+++ b/lib/type.gi
@@ -171,3 +171,21 @@ function(name)
     return fail;
 end);
 
+InstallGlobalFunction( LocationOfDeclaration,
+function(object)
+    local fid;
+    if IsFilter(object) then
+       fid := IdOfFilter(object);
+       if fid <> fail then
+           if IsBound(FILTERS_LOCATIONS[fid]) then
+               return FILTERS_LOCATIONS[fid];
+           fi; 
+       fi;
+    elif IsOperation(object) then
+       fid := Position(OPERATIONS, object);
+       if IsBound(OPERATIONS_LOCATIONS[fid + 1]) then
+           return OPERATIONS_LOCATIONS[fid + 1];
+       fi;
+    fi;
+    return fail;
+end);