99 lines
1.6 KiB
Plaintext
99 lines
1.6 KiB
Plaintext
%{
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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extern int yylineno;
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void yyerror(const char *s);
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int yylex();
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extern FILE *yyin;
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%}
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%union {
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int num;
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char *str;
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}
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%token <num> NUMBER
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%token <str> IDENTIFIER
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%token IF ELSE WHILE RETURN PRINT
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%token AND OR NOT GE LE EQ NE
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%nonassoc '>' '<' GE LE EQ NE
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%left OR
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%left AND
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%left '=' '+' '-'
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%left '*' '/' '%'
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%right NOT UMINUS
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%%
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program:
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| program statement
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;
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statement:
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expr ';' semicolons
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| IF '(' expr ')' statement ELSE statement
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| IF '(' expr ')' statement
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| WHILE '(' expr ')' statement
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| RETURN expr ';' semicolons
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| PRINT expr ';' semicolons
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| '{' program '}'
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;
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semicolons:
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/* empty */
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| semicolons ';'
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;
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expr:
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NUMBER
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| IDENTIFIER
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| IDENTIFIER '=' expr
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| expr '+' expr
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| expr '-' expr
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| expr '*' expr
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| expr '/' expr
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| expr '%' expr
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| expr AND expr
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| expr OR expr
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| NOT expr
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| '-' expr %prec UMINUS
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| '+' expr
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| expr '>' expr
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| expr '<' expr
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| expr GE expr
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| expr LE expr
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| expr EQ expr
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| expr NE expr
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| '(' expr ')'
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;
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%%
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void yyerror(const char *s) {
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fprintf(stderr, "Error at line %d: %s\n", yylineno, s);
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exit(1);
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}
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int main(int argc, char *argv[]) {
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if (argc < 2) {
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fprintf(stderr, "Usage: %s <input_file>\n", argv[0]);
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return 1;
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}
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FILE *input = fopen(argv[1], "r");
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if (!input) {
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perror("Error opening file");
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return 1;
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}
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yyin = input;
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yyparse();
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fclose(input);
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printf("Parsing completed successfully!\n");
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return 0;
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} |