diff --git a/pyecoreocl/compiler.py b/pyecoreocl/compiler.py
index b5f9edd..c02ccd5 100644
--- a/pyecoreocl/compiler.py
+++ b/pyecoreocl/compiler.py
@@ -62,7 +62,7 @@ def visitComparisonBinaryOperation(self, ctx):
     def visitCollectionCall(self, ctx):
         # We currently don't support implicity collection wrapping
         operation = ctx.attname.text
-        rule = rules.get(operation, default_collection_call)
+        rule = RuleSet.rules_collections.get(operation, default_collection_call)
         rule(self, ctx)
 
     def visitBooleanBinaryOperation(self, ctx):
@@ -280,17 +280,34 @@ def visitUnreservedName(self, ctx):
         return self.visitChildren(ctx)
 
 
-rules = {}
+class RuleSet:
+    rules_collections = {}
+    rules_primitives = {}
 
 
-def call_rule(fun):
-    names = fun.__name__[5:].split("_")
-    function_name = "".join([names[0], *(f.capitalize() for f in names[1:])])
-    rules[function_name] = fun
+def register_rule_set(decorator):
+    register_name = decorator.__name__.split("_")[0]
+
+    def inner(fun):
+        names = fun.__name__[5:].split("_")
+        function_name = "".join([names[0], *(f.capitalize() for f in names[1:])])
+        getattr(RuleSet, f"rules_{register_name}s")[function_name] = fun
+        return fun
+
+    return inner
+
+
+@register_rule_set
+def collection_rule(fun):
     return fun
 
 
-@call_rule
+@register_rule_set
+def primitive_rule(fun):
+    return fun
+
+
+@collection_rule
 def rule_collect_nested(emitter, ctx):
     emitter.inline("(")
     emitter.visit(ctx.argExp().body)
@@ -305,7 +322,7 @@ def rule_collect_nested(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_collect(emitter, ctx):
     emitter.inline("ocl.flatten(")
     emitter.visit(ctx.argExp().body)
@@ -320,7 +337,7 @@ def rule_collect(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_for_all(emitter, ctx):
     emitter.inline(f"all(")
     emitter.visit(ctx.argExp().body)
@@ -335,7 +352,7 @@ def rule_for_all(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_exists(emitter, ctx):
     emitter.inline(f"any(")
     emitter.visit(ctx.argExp().body)
@@ -350,14 +367,14 @@ def rule_exists(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_one(emitter, ctx):
     emitter.inline("(len(list(")
     rule_select(emitter, ctx)
     emitter.inline(")) == 1)")
 
 
-@call_rule
+@collection_rule
 def rule_select(emitter, ctx):
     variables = [arg.text for arg in ctx.argExp().varnames]
     varnames = ", ".join(variables)
@@ -374,7 +391,7 @@ def rule_select(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_reject(emitter, ctx):
     variables = [arg.text for arg in ctx.argExp().varnames]
     varnames = ", ".join(variables)
@@ -391,35 +408,35 @@ def rule_reject(emitter, ctx):
     emitter.inline("))")
 
 
-@call_rule
+@collection_rule
 def rule_includes(emitter, ctx):
     emitter.visit(ctx.argExp())
     emitter.inline(" in ")
     emitter.visit(ctx.expression)
 
 
-@call_rule
+@collection_rule
 def rule_excludes(emitter, ctx):
     emitter.visit(ctx.argExp())
     emitter.inline(" not in ")
     emitter.visit(ctx.expression)
 
 
-@call_rule
+@collection_rule
 def rule_not_empty(emitter, ctx):
     emitter.inline("len(")
     emitter.visit(ctx.expression)
     emitter.inline(") > 0")
 
 
-@call_rule
+@collection_rule
 def rule_is_empty(emitter, ctx):
     emitter.inline("len(")
     emitter.visit(ctx.expression)
     emitter.inline(") == 0")
 
 
-@call_rule
+@collection_rule
 def rule_at(emitter, ctx):
     emitter.visit(ctx.expression)
     emitter.inline("[")
@@ -427,42 +444,42 @@ def rule_at(emitter, ctx):
     emitter.inline("]")
 
 
-@call_rule
+@collection_rule
 def rule_size(emitter, ctx):
     emitter.inline("len(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_is_unique(emitter, ctx):
     emitter.inline("ocl.is_unique(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_sum(emitter, ctx):
     emitter.inline("sum(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_min(emitter, ctx):
     emitter.inline("min(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_max(emitter, ctx):
     emitter.inline("max(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_count(emitter, ctx):
     emitter.inline("list(")
     emitter.visit(ctx.expression)
@@ -471,7 +488,7 @@ def rule_count(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_includes_all(emitter, ctx):
     emitter.inline("all(e in ")
     emitter.visit(ctx.expression)
@@ -480,7 +497,7 @@ def rule_includes_all(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_excludes_all(emitter, ctx):
     emitter.inline("all(e not in ")
     emitter.visit(ctx.expression)
@@ -489,35 +506,35 @@ def rule_excludes_all(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_as_sequence(emitter, ctx):
     emitter.inline("list(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_as_set(emitter, ctx):
     emitter.inline("set(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_as_bag(emitter, ctx):
     emitter.inline("list(")
     emitter.visit(ctx.expression)
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_any(emitter, ctx):
     emitter.inline("next(iter(")
     emitter.visit(ctx.expression)
     emitter.inline("), None)")
 
 
-@call_rule
+@collection_rule
 def rule_sorted_by(emitter, ctx):
     emitter.inline("sorted(")
     emitter.visit(ctx.expression)
@@ -526,7 +543,7 @@ def rule_sorted_by(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_iterate(emitter, ctx):
     emitter.inline("ocl.flatten(")
     emitter.visit(ctx.argExp())
@@ -537,7 +554,7 @@ def rule_iterate(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_including(emitter, ctx):
     emitter.inline("itertools.chain(")
     emitter.visit(ctx.expression)
@@ -546,12 +563,12 @@ def rule_including(emitter, ctx):
     emitter.inline(",))")
 
 
-@call_rule
+@collection_rule
 def rule_append(emitter, ctx):
     rule_including(emitter, ctx)
 
 
-@call_rule
+@collection_rule
 def rule_prepend(emitter, ctx):
     emitter.inline("itertools.chain((")
     emitter.visit(ctx.argExp())
@@ -560,7 +577,7 @@ def rule_prepend(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_excluding(emitter, ctx):
     emitter.inline("_e for _e in ")
     emitter.visit(ctx.expression)
@@ -568,7 +585,7 @@ def rule_excluding(emitter, ctx):
     emitter.visit(ctx.argExp())
 
 
-@call_rule
+@collection_rule
 def rule_select_by_kind(emitter, ctx):
     emitter.inline("_e for _e in ")
     emitter.visit(ctx.expression)
@@ -577,28 +594,29 @@ def rule_select_by_kind(emitter, ctx):
     emitter.inline(")")
 
 
-@call_rule
+@collection_rule
 def rule_select_by_type(emitter, ctx):
     emitter.inline("_e for _e in ")
     emitter.visit(ctx.expression)
     emitter.inline(" if type(_e) == ")
     emitter.visit(ctx.argExp())
 
-@call_rule
+
+@collection_rule
 def rule_first(emitter, ctx):
     emitter.inline("next(iter(")
     emitter.visit(ctx.expression)
     emitter.inline("))")
 
 
-@call_rule
+@collection_rule
 def rule_last(emitter, ctx):
     emitter.inline("list(")
     emitter.visit(ctx.expression)
     emitter.inline(")[-1]")
 
 
-@call_rule
+@collection_rule
 def rule_index_of(emitter, ctx):
     emitter.inline("next(_i for _i, _e in enumerate(")
     emitter.visit(ctx.expression)
@@ -606,7 +624,8 @@ def rule_index_of(emitter, ctx):
     emitter.visit(ctx.argExp().body[0])
     emitter.inline(")")
 
-@call_rule
+
+@collection_rule
 def rule_closure(emitter, ctx):
     emitter.inline("ocl.closure(")
     emitter.visit(ctx.expression)
diff --git a/tests/test_collection_lib.py b/tests/test_collection_lib.py
index c894193..811dddb 100644
--- a/tests/test_collection_lib.py
+++ b/tests/test_collection_lib.py
@@ -203,5 +203,4 @@ class A:
     x1, x2 = A(children=[]), A(children=None)
     a = A(children=[x1, x2])
 
-    print(!Sequence{a}->closure(e | e.children)->asSequence()!)
     assert !Sequence{a}->closure(e | e.children)->asSequence()! == [x1, x2]
\ No newline at end of file