steve.jison

gistfile1.txt

/* Part of the grammar of Steve */

%lex
%%

\s+                         { /* ignore whitespace */ }
[0-9]+"."[0-9]+\b           { return 'FLOAT'; }
[0-9]+\b                    { return 'INT'; }
\"[^\"]+\"                  { yytext = yytext.substr(1, yyleng-2); return 'STR'; }
"int"                       return 'INTTYPE'
"float"                     return 'FLOATTYPE'
"string"                    return 'STRTYPE'
"=>"                        return 'RETURNS'
"["                         return '['
"]"                         return ']'
"{"                         return '{'
"}"                         return '}'
","                         return ','
<<EOF>>                     return 'EOF'
.                           return 'INVALID'

/lex

%left UMINUS


%start grammar
%%

grammar
    : type_decl RETURNS expr EOF        { console.log($expr); return $expr }
    | EOF                               { return null }
    ;

type
    : INTTYPE
    | FLOATTYPE
    | STRTYPE
    ;

type_decl
    : type '[' ']'
    | type
    ;

number
    : '-' number %prec UMINUS           { $$ = -$2; }
    | INT                               { $$ = Number(yytext); }
    | FLOAT                             { $$ = Number(yytext); }
    ;

primitive
    : number                            { $$ = $1 }
    | STR                               { $$ = $1 }
    ;

primitives
    : primitives ',' primitive          { $$ = $primitives; $$.push($primitive); }
    | primitive                         { $$ = [$primitive] }
    ;

list
    : type_decl '{' primitives '}'      { $$ = $primitives; }
    ;

expr
    : list                              { $$ = $list; }
    | primitive                         { $$ = $primitive; }
    ;