bc_interactive.c

#include "../include/rdesc.h"
#include "../include/grammar.h"
#include "../src/common.h"
 
#include "grammar/bc.h"
#include "lib/bc_interpreter.h"
#include "lib/exblex.h"
 
#include <stdint.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
 
 
void program(struct exblex *lex, struct rdesc *p)
{
        char buf[4096];
 
        int pump_res;
 
        while (true) {
                unwrap(rdesc_start(p, NT_STMT));
 
                pump_res = -1;
 
                printf("> ");
                while (pump_res != RDESC_READY) {
                        if (fgets(buf, 4096, stdin) == NULL) {
                                rdesc_reset(p);
 
                                return;
                        }
 
                        exblex_init(lex, buf, bc_tks);
 
                        uint16_t tk;
                        while ((tk = exblex_next(lex)) != 0) {
                                const void *seminfo = exblex_current_seminfo(lex);
                                pump_res =
                                        rdesc_pump(p, tk, &seminfo);
 
                                if (pump_res == RDESC_CONTINUE)
                                        continue;
 
                                break;
                        }
 
                        if (tk == 0 && lex->cur <= strlen(buf)) {
                                printf("  %*s", (int) lex->cur, "^\n");
                                printf("Invalid token, ignoring tokens after "
                                       "index %zu!\n", lex->cur);
                        }
 
                        if (pump_res == RDESC_NOMATCH) {
                                printf("SYNTAX ERROR!\n");
                                rdesc_reset(p);
 
                                break;
                        }
 
                        if (pump_res == RDESC_CONTINUE || pump_res == -1)
                                printf("  ");
                }
 
                if (pump_res == RDESC_READY) {
                        struct rdesc_node *cst;
                        cst = rdesc_root(p);
 
                        printf("< (%.2lf)\n", bc_interpreter(p, cst));
                }
        }
}
 
 
int main(void)
{
        struct exblex lex;
        struct rdesc_grammar grammar;
        struct rdesc p;
 
        unwrap(rdesc_grammar_init(&grammar,
                                  BC_PRODUCTION_COUNT,
                                  BC_MAX_ALTERNATIVE_COUNT,
                                  BC_MAX_ALTERNATIVE_SIZE,
                                  (struct rdesc_grammar_symbol *) bc));
        unwrap(rdesc_init(&p,
                          &grammar,
                          sizeof(void *) /* semantic info holds char* */,
                          bc_tk_destroyer));
 
        printf("Basic Calculator, librdesc sample program\n");
        program(&lex, &p);
 
        rdesc_destroy(&p);
        rdesc_grammar_destroy(&grammar);
}