Changeset 1704

Timestamp:

10/25/08 00:42:49 (2 months ago)

Author:

Chuck.Esterbrook

Message:

Add support for multitarget assignment in for statements:

for key, value in aDictionary
    trace key, value
for a, b in [[1, 2], [3, 4]]
    print a + b

This is a patch application, part 1 of 2.
ticket:38
credit:hopscc

Location:

cobra/trunk

Files:

• Developer/IntermediateReleaseNotes.text (modified) (1 diff)
• Source/CobraParser.cobra (modified) (7 diffs)
• Source/Compiler.cobra (modified) (1 diff)
• Source/Statements.cobra (modified) (3 diffs)
• Source/Types.cobra (modified) (1 diff)
• Tests/110-basics-two/910-multi-assign.cobra (modified) (3 diffs)
• Tests/110-basics-two/912-multi-assign.cobra (modified) (2 diffs)

cobra/trunk/Developer/IntermediateReleaseNotes.text

@@ -21 +21 @@
 .code
         a,b,c = ['val1', 'val2', 'val3']
-
+Also support such assignment in for statements for (generic) dictionaries and lists
+.code
+    for key, value in aDictionary
+        trace key, value
+    for a, b in [[1, 2], [3, 4]]
+        print a + b
 
 * Added support for a new compiler directive 'args' that takes command line options and applies them to the compilation environment from that point on.

cobra/trunk/Source/CobraParser.cobra

@@ -1991 +1991 @@
                 """
                 numeric    for int x = 0 up to n step 2
-                enumerable for Customer cust in customers
+                enumerable for cust as Customer in customers
+                           for k, v in dict
+                           for i, j, k in listOfThrees
                 """
                 token = .expect('FOR')
                 varr = .nameExpr
+                if .optional('COMMA')     # forStmt multiarg    for v1,... 
+                        args = .commaSepNameIds(['IN' ,'EOL'])
+                        if .last.which <> 'IN'
+                                .throwError("Comma separated nameId list in forStatement needs to terminate with an IN token ('in')")
+                        if args.count == 0  # "for v1, in ..."  single multiarg variable 
+                                .undo  # 'in' token
+                                return .forStmt(token, varr)
+                        else
+                                args.insert(0, varr)
+                                what = .expression
+                                name = 'forEnumVar[what.serialNum]'  # will get made more unique by For Stmt 
+                                nameToken = token.copy('ID', name)
+                                varr = IdentifierExpr(nameToken, name)
+                                return ForEnumerableStmt(token, varr, args, what, .block)
+
+                # forStmt single variable assign - for v {in,=} ...
                 peek = .peek.which
                 if peek=='ASSIGN'
@@ -2704 +2722 @@
                 args = .commaSepIds(['ASSIGN', 'EOL'])
                 if .last.which <> 'ASSIGN'
-                        .throwError("Comma separated multiArg identifier list needs to end with an assignment ('=')")
+                        .throwError('Comma separated identifier list needs to end with an assignment ("=").')
                 assignTkn = .last
                 rhs = .expression
@@ -2746 +2764 @@
                         stmts.add(AssignExpr(assignTkn, assignTkn.which, id , idxExpr))
                         count += 1
-                #return BlockStmt(token.copy('INDENT', ''), stmts)      
-                # if prefer exception when nArgs > nRHSExprs Uncomment above line and lose lines below 
-                tryBlock = BlockStmt(token.copy('INDENT',''), stmts)            
-                catchBlocks = List<of CatchBlock>()
-                catchStmts = List<of Stmt>()
-                catchStmts.add(PassStmt(token.copy('PASS', 'pass')))
-                catchBlock = BlockStmt(token.copy('INDENT',''), catchStmts)
-                catchType = TypeIdentifier(token.copy('ID', 'IndexOutOfRangeException'))
-                catchBlocks.add(CatchBlock(token.copy('CATCH', 'catch'), catchType, catchBlock))
-                # 'IndexOutOfRangeException' for Arrays and Strings 
-                catchType = TypeIdentifier(token.copy('ID', 'ArgumentOutOfRangeException'))
-                catchBlocks.add(CatchBlock(token.copy('CATCH', 'catch'), catchType, catchBlock))
-                # 'ArgumentOutOfRangeException' for others, probably something else yet to find
-                return TryStmt(token.copy('TRY', 'try'), tryBlock, catchBlocks, nil, nil)
+                return BlockStmt(token.copy('INDENT', ''), stmts)       
 
         def callExpr as Expr
@@ -2863 +2868 @@
                 return exprs
                 
-        def commaSepIds(terminators as IList<of String>) as List<of Expr>
-                """
+        def commaSepNameIds(terminators as IList<of String>) as List<of Expr>
+                return _commaSepLValues(terminators, true)
+
+        def      commaSepIds(terminators as IList<of String>) as List<of Expr>
+                return _commaSepLValues(terminators, false)
+                        
+        def _commaSepLValues(terminators as IList<of String>, expectingNameIds as bool ) as List<of Expr>
+                """
+                pickup comma sep stream of Identifiers or NameIds 
                 Example source
                         ... idexpr, TERMINATOR
@@ -2870 +2882 @@
                         ... idexpr, idexpr, ... TERMINATOR
                 Returns
-                        A list of Identifier Expressions ([DotExpr] IdentifiersExpr) 
-                Notes
-                        The terminator token is consumed, but can be examined with .last.
+                        A list of Identifier Expressions ([DotExpr] IdentifiersExpr) or NameIds 
                 """
                 expectSep = false
@@ -2888 +2898 @@
                         .newOpStack
                         try
-                                exprs.add(.idExpression(0, nil))
+                                if expectingNameIds
+                                        exprs.add(.nameExpr)
+                                else
+                                        exprs.add(.idExpression(0,nil))
                         finally
                                 .delOpStack
@@ -3453 +3466 @@
                                 state=1
                         else if token.which == 'ID'
-                                if not (token.text[0] == '_' or Utils.startsWithLowerLetter(token.text))
-                                        break
                                 state = 2
                         else if token.which == 'COMMA' 

cobra/trunk/Source/Compiler.cobra

@@ -1243 +1243 @@
                 return _libraryClass('System.Collections.Generic.List<of>')
 
-        def idictionaryOfType as Class
-                return _libraryClass('System.Collections.Generic.IDictionary<of,>')
+        def idictionaryType as Box
+                return _libraryBox('System.Collections.IDictionary')
+                
+        def idictionaryOfType as Box
+                return _libraryBox('System.Collections.Generic.IDictionary<of,>')
 
         def dictionaryOfType as Class

cobra/trunk/Source/Statements.cobra

@@ -522 +522 @@
         var _what as Expr
         var _varNumber as int
+        var _multiArgs as List<of Expr>?                # actually contains NameExprs
 
         def init(token as IToken, varr as NameExpr, what as Expr, block as BlockStmt)
@@ -527 +528 @@
                 _what = what
 
+        def init(token as IToken, varr as NameExpr, args as List<of Expr>, what as Expr, block as BlockStmt)
+                # multiArg assignment in for stmt
+                .init(token, varr, what, block)
+                _multiArgs = args
+                
         def addSubFields
                 base.addSubFields
                 .addField('_what', _what)
                 .addField('_varNumber', _varNumber)
+                .addField('_multiArgs', _multiArgs)
 
         get what from var
         
         get varNumber from var
+        
+        get multiArgs from var
         
         def _bindImp
@@ -546 +555 @@
                 else
                         _var = .bindVar(_varExpr)
+                        if _multiArgs
+                                _unpackMultiArgStmts
                         base._bindImp
                         _varNumber = .compiler.curBox.makeNextPrivateSerialNumber
                         _block.bindImp
-
+                
+        def _unpackMultiArgStmts
+                """
+                Handle expansion of statements for multiArg variables in for statements: 
+                for k, v in <dict>  # becomes
+                        for varExpr_uniq in <dict>
+                                k = varExpr_uniq.key
+                                v = varExpr_uniq.value
+                and 
+                for a, b, c in <IEnumerable (of triplets in this case)> becomes
+                        for varExpr_uniq in <IEnumerable>
+                                a = varExpr_uniq[0]
+                                b = varExpr_uniq[1]
+                                c = varExpr_uniq[2]
+                with rest of block following                            
+                """
+                stmts = List<of Stmt>()
+                varName = _varExpr.name # "[_varExpr.name]_[.serialNum]"
+                token = _token.copy
+                count = 0
+                if .what.type.isDictionaryLike
+                        # assume enumerator will return KeyValue so cant have other than 2 multiargs
+                        if _multiArgs.count <> 2
+                                .throwError('Cannot have other than two multiarg variables in a for statement as assignment targets from a Dictionary')
+                        kvRHS = ['key', 'value']
+                        for id in _multiArgs
+                                forVar    = IdentifierExpr(token.copy('ID', varName), varName)
+                                rhsToken  = token.copy('ID', kvRHS[count])
+                                keyOrVal  = MemberExpr(rhsToken )
+                                kvExpr    = BinaryOpExpr.make(token.copy('DOT', '.'), 'DOT', forVar, keyOrVal) # forVar.{key,value}
+                                assignTkn = token.copy('ASSIGN', '=')
+                                # print id.toCobraSource, '=', kvExpr.toCobraSource
+                                stmts.add(AssignExpr(assignTkn, assignTkn.which, id, kvExpr))  # id = forVar.{key,value}
+                                count += 1
+                else  # enumeration, each item of which is matching count sequence
+                        # TODO: ? Add check varName.count <> multArgs.count throw RTException
+                        for id in _multiArgs
+                                intToken = token.copy('INTEGER_LIT', '[count]')
+                                intToken.value = count
+                                countIntLit = IntegerLit(intToken)
+                                exprs = List<of Expr>()
+                                exprs.add(countIntLit)
+                                forVar = IdentifierExpr(token.copy('ID', varName), varName)
+                                idxExpr = IndexExpr(token.copy('LBRACKET', r'['), forVar, exprs)  # forVar[count]
+                                assignTkn = token.copy('ASSIGN', '=')
+                                stmts.add(AssignExpr(assignTkn, assignTkn.which, id, idxExpr))  
+                                count += 1
+                _block.stmts.insertRange(0, stmts)
+        
         def inferredType as IType? is override
                 assert _what.type

cobra/trunk/Source/Types.cobra

@@ -1603 +1603 @@
 
 
+extend IType
+
+        def isDictionaryLike as bool
+                """
+                Returns true if the receiver is like a dictionary, such as being an actual dictionary type or a nilable version thereof.
+                The dynamic type will also return true because at compile-time, dynamic is considered to be like everything.
+                Requires Node.getCompiler
+                """
+                type = this
+                if type inherits NilableType
+                        return type.theWrappedType.isDictionaryLike
+                tp = Node.getCompiler  # TODO? expand ITypeProvider to cover idictionaryType, dictionaryOfType, idictionaryOfType
+                if type.isDescendantOf(tp.idictionaryType)
+                        return true
+                genericDict = tp.dictionaryOfType
+                if type.isDescendantOf(genericDict)
+                        return true
+                if type inherits Box
+                        if type.genericDef is genericDict
+                                return true
+                genericIDict = tp.idictionaryOfType
+                if type.isDescendantOf(genericIDict)
+                        return true
+                if type inherits Box
+                        if type.genericDef is genericIDict
+                                return true
+                if type.isDynamic
+                        return true
+                return false
+
+
 class TypeUtil
         

cobra/trunk/Tests/110-basics-two/910-multi-assign.cobra

@@ -88 +88 @@
                 
         def nonMatchCount
-                a, b, c = [11, 12]
+                expect ArgumentOutOfRangeException
+                        a, b, c = [11, 12]
                 assert a == 11
                 assert b == 12
                 assert c == 0  # instantiated but unassigned
-
                 f, = [3, 4]
                 assert f == 3
@@ -118 +118 @@
                 m = ''
                 c1 as Object = 'x'
-                l, m, n, c1 = @[1, 'Two', c'3']
+                expect IndexOutOfRangeException
+                        l, m, n, c1 = @[1, 'Two', c'3']
                 
                 assert l == 1
@@ -125 +126 @@
                 assert c1 == 'x'
         
-                p, q, r = 'ab'
+                expect IndexOutOfRangeException
+                        p, q, r = 'ab'
                 assert p == c'a'
                 assert q == c'b'

cobra/trunk/Tests/110-basics-two/912-multi-assign.cobra

@@ -14 +14 @@
                 ma.nonLocalVar
                 ma.forIEnum
+                ma.forSwap
 
         def nonLocalVar
@@ -41 +42 @@
                 
         def forIEnum
-                list = [1, 2, 3, 4]
+                list = [1, 2, 3, 4]  # TODO: should be an error with too many elements
                 a, b = for k in list get k 
                 assert a == 1
                 assert b == 2
+                
+        def forSwap
+                # common variable swap idiom ( python a,b = b,a)
+                a = 99
+                b = 100
+                a, b = [b, a]
+                assert a == 100
+                assert b == 99