Ticket #34: var-is-ambig-wkround.patch

Source/CobraParser.cobra

@@ -681 +681 @@
                 Example source:
                         # The | below is not literal--it's where this method starts parsing.
                         def compute
-                                |is virtual, protected
+                                |{is,isdecl} virtual, protected
                 Example return values:
                         []
                         ['shared']
@@ -693 +693 @@
                 if _validIsNames is nil
                         _validIsNames = ['fake', 'shared', 'virtual', 'nonvirtual', 'override', 'new', 'public', 'protected', 'private', 'internal', 'abstract', 'partial']
                 names = List<of String>(_isNamesStack)
-                if .optional('IS') is nil
+                if .optional('IS', 'ISDECL') is nil
                         return names
                 while true
                         what = .grab.text
@@ -1152 +1152 @@
                                 type = .typeProvider.defaultType
                 docString = '' to ?
                 isNames = List<of String>(_isNamesStack)
-                if .peek.which=='IS'
+                if .peek.which=='IS' or .peek.which=='ISDECL'
                         isNames = .isDeclNames
                         attribs = .hasAttribs
                         assert .last.which=='EOL'

Source/KeywordSpecs.cobra

@@ -92 +92 @@
                                 'body        | declarative: Declare the body of a method, indexer or property after blocked contracts or unit tests.',
                                 'test        | declarative: Declare a unit test attached to the containing declaration.',
                                 'shared      | declarative: Specify that a member is shared among all instances. (Called `static` in some languages.)',
-                                'is          | declarative: Specify modifies on a member such as `override` and `shared`.',
+                                'is          | declarative: synonym for isdecl for modifiers, keyword for testing item equivalence',
+                                'isdecl      | declarative: Specify modifiers on a member such as `private` and `shared`.',
                                 'event       | declarative: Declare an event.',
                                 'of          | declarative: Specify the underlying type of an enumeration. Also, specify type arguments to a generic type.',
                                 'inlined (r) | declarative: ',

Tests/400-misc-bugs/221-is-ambig-wkround.cobra

@@ +1 @@
+# test for workaround for grammar ambiguity with 'is' expression and 'is' for typing in boxVar 
+# use 'isdecl' for keyword for typing instead of 'is'
+# grammar: var name [= <assignExpr>] [isdecl <declTypes>]
+class VarIsNameAssign
+        var myVal0 is shared,private
+        var myVal1       = 'works'
+        var myValNotBroke = "now not broke" isdecl shared, private 
+        # working synonym for 
+#       var myValNotBroke = "now not broke" is shared, private 
+    var xisy = 'xx' is 'yy' isdecl shared
+        var isStr = 'xx'.getType is String isdecl shared
+        
+        def main is shared
+                assert not .myVal0 
+                v = VarIsNameAssign()
+                assert v.myVal1 == 'works'              
+                a = v
+                b = VarIsNameAssign()
+                assert a is v
+                assert .myValNotBroke == 'now not broke'
+                assert a is v
+                assert a is not b
+                assert not .xisy
+                assert .isStr

Tests/400-misc-bugs/220-is-ambig.cobra

@@ +1 @@
+# Show broken compile for grammar ambiguity with 'is' expression and 'is'
+# used for typing in boxVar in single line decl with both assignment and typing
+# grammar: var name [= <assignExpr>] [is <declTypes>]
+# ( 'is' is a keyword in expression as well as keyword for typing...)
+class VarIsNameAssign
+        var myVal0 is shared,private
+        var myVal1       = 'works'
+        var myValBroke = "this is broke" is shared,private # .error. Expecting an expression. "shared" is a reserved keyword that is not expected here.                 
+#                                       <<- compile error here when broken
+
+        def main is shared
+                assert not .myVal0 
+                v = VarIsNameAssign()
+                assert v.myVal1 == 'works'              
+                a = v
+                b = VarIsNameAssign()
+                assert a is v
+                assert .myValBroke == 'this is broke'
+                assert a is v
+                assert a is not b
+