"variables" vocab with uniform-access global, dynamic, and local vars

extra/variables/variables.factor

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+! (c)2010 Joe Groff bsd license
+USING: accessors definitions fry kernel locals.types namespaces parser
+see sequences words ;
+FROM: help.markup.private => link-effect? ;
+IN: variables
+
+PREDICATE: variable < word
+    "variable-setter" word-prop ;
+
+GENERIC: variable-setter ( word -- word' )
+
+M: variable variable-setter "variable-setter" word-prop ;
+M: local-reader variable-setter "local-writer" word-prop ;
+
+SYNTAX: set:
+    scan-object variable-setter suffix! ;
+
+: [variable-getter] ( variable -- quot )
+    '[ _ get ] ;
+: [variable-setter] ( variable -- quot )
+    '[ _ set ] ;
+
+: (define-variable) ( word getter setter -- )
+    [ (( -- value )) define-inline ]
+    [
+        [
+            [ name>> "set: " prepend <uninterned-word> ]
+            [ over "variable-setter" set-word-prop ] bi
+        ] dip (( value -- )) define-inline
+    ] bi-curry* bi ;
+
+: define-variable ( word -- )
+    dup [ [variable-getter] ] [ [variable-setter] ] bi (define-variable) ;
+
+SYNTAX: VAR:
+    CREATE-WORD define-variable ;    
+
+M: variable definer drop \ VAR: f ;
+M: variable definition drop f ;
+M: variable link-effect? drop f ;
+M: variable print-stack-effect? drop f ;
+
+TUPLE: global-box value ;
+
+PREDICATE: global-variable < variable
+    "variable-setter" word-prop def>> first global-box? ;
+
+: [global-getter] ( box -- quot )
+    '[ _ value>> ] ;
+: [global-setter] ( box -- quot )
+    '[ _ (>>value) ] ;
+
+: define-global ( word -- )
+    global-box new [ [global-getter] ] [ [global-setter] ] bi (define-variable) ;
+
+SYNTAX: GLOBAL:
+    CREATE-WORD define-global ;
+
+M: global-variable definer drop \ GLOBAL: f ;
+