Named values enhancement (#184).

examples/classy_test.src

@@ -0,0 +1,7 @@
+class Chris extends Person {
+}
+
+main {
+	var string cool;
+	printnat(cool);
+}

examples/nv_classy_ast.jison

@@ -0,0 +1,126 @@
+/* description: ClassyLang grammar with AST-building actions. Very classy. */
+/* 
+  To build parser:
+
+    $ ./bin/jison examples/classy_ast.jison examples/classy.jisonlex 
+
+*/
+
+/* author: Zach Carter */
+
+%{
+    function prependChild(node, child){
+      node.splice(2,0,child); 
+      return node;
+    }
+%}
+
+%ebnf
+
+%right ASSIGN
+%left OR
+%nonassoc EQUALITY GREATER
+%left PLUS MINUS
+%left TIMES
+%right NOT
+%left DOT
+
+%%
+
+pgm
+    : cdl MAIN LBRACE vdl el RBRACE ENDOFFILE
+        {{$$ = ['PROGRAM',{},$1,$4,$5]; console.log(JSON.stringify($$, null, 4)); return $$; }}
+    ;
+
+cdl
+    : c cdl
+        {$$ = prependChild($2, $1);}
+    | 
+        {{$$ = ['CLASS_DECL_LIST',{}];}}
+    ;
+
+c
+    : CLASS id[class_name] EXTENDS id[base_class] LBRACE vdl mdl RBRACE
+        {{$$ = ['CLASS_DECL',{},$class_name,$base_class,$vdl,$mdl];}}
+    ;
+
+vdl
+    : VAR t id SEMICOLON vdl
+        {{$$ = prependChild($5, ['VAR_DECL',{},$2,$3]);}}
+    | 
+        {{$$ = ['VAR_DECL_LIST',{}];}}
+    ;
+
+mdl
+    : t id LPAREN t id RPAREN LBRACE vdl el RBRACE mdl
+        {{$$ = prependChild($11, ['METHOD_DECL',{},$1,$2,$4,$5,$8,$9]);}}
+    | 
+        {{$$ = ['METHOD_DECL_LIST',{}];}}
+    ;
+
+t
+    : NATTYPE
+        {{$$ = ['NAT_TYPE',{}];}}
+    | id
+        {$$ = $1}
+    ;
+
+id
+    : ID
+        {{$$ = ['AST_ID',{val:yytext}]}}
+    ;
+
+el
+    : e SEMICOLON el
+        {$$ = prependChild($3, $1);}
+    | e SEMICOLON
+        {{$$ = ['EXPR_LIST',{},$1];}}
+    ;
+
+e
+    : NATLITERAL
+        {{$$ = ['NAT_LITERAL_EXPR',{val:parseInt(yytext)}];}}
+    | NUL
+        {{$$ = ['NULL_EXPR',{}];}}
+    | id
+        {{$$ = ['ID_EXPR',{},$1];}}
+    | NEW id
+        {{$$ = ['NEW_EXPR',{},$2];}}
+    | THIS
+        {{$$ = ['THIS_EXPR',{}];}}
+    | IF LPAREN e RPAREN LBRACE el RBRACE ELSE LBRACE el RBRACE
+        {{$$ = ['IF_THEN_ELSE_EXPR',{},$3,$6,$10];}}
+    | FOR LPAREN e SEMICOLON e SEMICOLON e RPAREN LBRACE el RBRACE
+        {{$$ = ['FOR_EXPR',{},$3,$5,$7,$10];}}
+    | READNAT LPAREN RPAREN
+        {{$$ = ['READ_EXPR',{}];}}
+    | PRINTNAT LPAREN e RPAREN
+        {{$$ = ['PRINT_EXPR',{},$3];}}
+    | e PLUS e
+        {{$$ = ['PLUS_EXPR',{},$1,$3];}}
+    | e MINUS e
+        {{$$ = ['MINUS_EXPR',{},$1,$3];}}
+    | e TIMES e
+        {{$$ = ['TIMES_EXPR',{},$1,$3];}}
+    | e EQUALITY e
+        {{$$ = ['EQUALITY_EXPR',{},$1,$3];}}
+    | e GREATER e
+        {{$$ = ['GREATER_THAN_EXPR',{},$1,$3];}}
+    | NOT e
+        {{$$ = ['NOT_EXPR',{},$2];}}
+    | e OR e
+        {{$$ = ['OR_EXPR',{},$1,$3];}}
+    | e DOT id
+        {{$$ = ['DOT_ID_EXPR',{},$1,$3];}}
+    | id ASSIGN e
+        {{$$ = ['ASSIGN_EXPR',{},$1,$3];}}
+    | e DOT id ASSIGN e
+        {{$$ = ['DOT_ASSIGN_EXPR',{},$1,$3,$5];}}
+    | id LPAREN e RPAREN
+        {{$$ = ['METHOD_CALL_EXPR',{},$1,$3];}}
+    | e DOT id LPAREN e RPAREN
+        {{$$ = ['DOT_METHOD_CALL_EXPR',{},$1,$3,$5];}}
+    | LPAREN e RPAREN
+        {$$ = $2;}
+    ;
+

lib/jison.js

@@ -284,12 +284,21 @@ generator.buildProductions = function buildProductions(bnf, productions, nonterm
                     var count = {},
                         names = {};
                     for (i=0;i<rhs.length;i++) {
-                        if (names[rhs[i]]) {
-                            names[rhs[i]+(++count[rhs[i]])] = i+1;
+                        // check for aliased names, e.g., id[alias]
+                        var rhs_i = rhs[i].match(/\[[a-zA-Z][a-zA-Z0-9_-]*\]/);
+                        if (rhs_i) {
+                            rhs_i = rhs_i[0].substr(1, rhs_i[0].length-2);
+                            rhs[i] = rhs[i].substr(0, rhs[i].indexOf('['));
                         } else {
-                            names[rhs[i]] = i+1;
-                            names[rhs[i]+"1"] = i+1;
-                            count[rhs[i]] = 1;
+                            rhs_i = rhs[i];
+                        }
+
+                        if (names[rhs_i]) {
+                            names[rhs_i + (++count[rhs_i])] = i+1;
+                        } else {
+                            names[rhs_i] = i+1;
+                            names[rhs_i + "1"] = i+1;
+                            count[rhs_i] = 1;
                         }
                     }
                     action = action.replace(/\$([a-zA-Z][a-zA-Z0-9_]*)/g, function (str, pl) {
@@ -312,19 +321,25 @@ generator.buildProductions = function buildProductions(bnf, productions, nonterm
                     });
                 actions.push(action);
 
+                // done with aliases; strip them.
+                rhs = rhs.map(function(e,i) { return e.replace(/\[[a-zA-Z_][a-zA-Z0-9_-]*\]/g, '') });
                 r = new Production(symbol, rhs, productions.length+1);
                 // precedence specified also
                 if (handle[2] && operators[handle[2].prec]) {
                     r.precedence = operators[handle[2].prec].precedence;
                 }
             } else {
+                // no action -> don't care about aliases; strip them.
+                rhs = rhs.map(function(e,i) { return e.replace(/\[[a-zA-Z_][a-zA-Z0-9_-]*\]/g, '') });
                 // only precedence specified
                 r = new Production(symbol, rhs, productions.length+1);
                 if (operators[handle[1].prec]) {
                     r.precedence = operators[handle[1].prec].precedence;
                 }
             }
         } else {
+            // no action -> don't care about aliases; strip them.
+            handle = handle.replace(/\[[a-zA-Z_][a-zA-Z0-9_-]*\]/g, '');
             rhs = handle.trim().split(' ');
             for (i=0; i<rhs.length; i++) {
                 if (rhs[i] === 'error') her = true;

tests/parser/actions.js

@@ -460,3 +460,47 @@ exports["test parse params"] = function() {
 
     assert.equal(parser.parse('y', "foo", "bar"), "foobar", "semantic action");
 };
+
+exports["test symbol aliases"] = function() {
+    var lexData = {
+        rules: [
+           ["a", "return 'a';"],
+           ["b", "return 'b';"],
+           ["c", "return 'c';"]
+        ]
+    };
+    var grammar = {
+        bnf: {
+            "pgm" :[ ["expr[alice] expr[bob] expr[carol]", "return $alice+$bob+$carol;"] ],
+            "expr"   :[ ["a", "$$ = 'a';"],
+                        ["b", "$$ = 'b';"],
+                         ["c", "$$ = 'c';"] ]
+        }
+    };
+
+    var parser = new Jison.Parser(grammar);
+    parser.lexer = new RegExpLexer(lexData);
+    assert.equal(parser.parse('abc'), "abc", "should return original string");
+};
+
+exports["test symbol aliases in ebnf"] = function() {
+    var lexData = {
+        rules: [
+           ["a", "return 'a';"],
+           ["b", "return 'b';"],
+           ["c", "return 'c';"]
+        ]
+    };
+    var grammar = {
+        ebnf: {
+            "pgm" :[ ["expr[alice] (expr[bob] expr[carol])+", "return $alice+$2;"] ],
+            "expr"   :[ ["a", "$$ = 'a';"],
+                        ["b", "$$ = 'b';"],
+                         ["c", "$$ = 'c';"] ]
+        }
+    };
+
+    var parser = new Jison.Parser(grammar);
+    parser.lexer = new RegExpLexer(lexData);
+    assert.equal(parser.parse('abc'), "ab", "should tolerate aliases in subexpression");
+};