diff options
Diffstat (limited to 'src/parser.y')
| -rw-r--r-- | src/parser.y | 52 |
1 files changed, 34 insertions, 18 deletions
diff --git a/src/parser.y b/src/parser.y index 5952aa9..a758e84 100644 --- a/src/parser.y +++ b/src/parser.y @@ -1,14 +1,14 @@ +%error-verbose %{ #include <stdio.h> #include "ast.h" -extern char *yytext; -extern int yylineno; extern int yylex(); - IMP_ASTNode *ast_root; -void yyerror(const char *s) { +void yyerror(const char *s) { + extern char *yytext; + extern int yylineno; fprintf(stderr, "Parse error at token \"%s\", line %d: %s\n", yytext, yylineno, s); } %} @@ -37,25 +37,36 @@ void yyerror(const char *s) { %token T_ASSIGN %token T_LPAREN T_RPAREN T_COM T_SEM -%type <node> prog stm var aexp bexp procd procc -%type <node_list> args +%type <node> prog tlstm stm var aexp bexp procd procc +%type <node_list> argl, varl %% -prog : stm +prog : tlstm { ast_root = $1; } ; -stm : T_SKIP - { $$ = imp_ast_skip(); } - | var T_ASSIGN aexp - { $$ = imp_ast_assign($1, $3); } - | T_LPAREN stm T_SEM stm T_RPAREN +tlstm : T_LPAREN tlstm T_SEM tlstm T_RPAREN + { $$ = imp_ast_seq($2, $4); } + | tlstm T_SEM tlstm + { $$ = imp_ast_seq($1, $3); } + | tlstm T_SEM + { $$ = $1; } + | stm + { $$ = $1; } + | procd + { $$ = $1; } + +stm : T_LPAREN stm T_SEM stm T_RPAREN { $$ = imp_ast_seq($2, $4); } | stm T_SEM stm { $$ = imp_ast_seq($1, $3); } | stm T_SEM { $$ = $1; } + | T_SKIP + { $$ = imp_ast_skip(); } + | var T_ASSIGN aexp + { $$ = imp_ast_assign($1, $3); } | T_IF bexp T_THEN stm T_ELSE stm T_END { $$ = imp_ast_if($2, $4, $6); } | T_IF bexp T_THEN stm T_END @@ -64,10 +75,9 @@ stm : T_SKIP { $$ = imp_ast_while($2, $4); } | T_VAR var T_ASSIGN aexp T_IN stm T_END { $$ = imp_ast_let($2, $4, $6); } - | procd - { $$ = $1; } | procc { $$ = $1; } + ; var : T_ID @@ -116,17 +126,23 @@ bexp : bexp T_OR bexp { $$ = imp_ast_rop(IMP_AST_ROP_EQ, imp_ast_int(0), imp_ast_int(1)); } ; -args : var +argl : aexp + { $$ = imp_ast_list($1, NULL); } + | argl T_COM aexp + { $$ = imp_ast_list($3, $1); } + ; + +varl : var { $$ = imp_ast_list($1, NULL); } - | args T_COM var + | argl T_COM var { $$ = imp_ast_list($3, $1); } ; -procd : T_PROC T_ID T_LPAREN args T_SEM args T_RPAREN T_BEGIN stm T_END +procd : T_PROC T_ID T_LPAREN varl T_SEM varl T_RPAREN T_BEGIN stm T_END { $$ = imp_ast_procdecl($2, $4, $6, $9); } ; -procc : T_ID T_LPAREN args T_SEM args T_RPAREN +procc : T_ID T_LPAREN argl T_SEM varl T_RPAREN { $$ = imp_ast_proccall($1, $3, $5); } ; %% |