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// Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
// SPDX-License-Identifier: MIT
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <term.h>
#include <print.h>
#include <log.h>
struct term *new_term(term_type type)
{
struct term *term = malloc(sizeof(*term));
if (!term)
fatal("out of memory!\n");
term->type = type;
return term;
}
void free_term(struct term *term)
{
switch (term->type) {
case ABS:
free_term(term->u.abs.term);
free(term);
break;
case APP:
free_term(term->u.app.lhs);
free_term(term->u.app.rhs);
free(term);
break;
case VAR:
free(term);
break;
case REF:
free(term);
break;
default:
fatal("invalid type %d\n", term->type);
}
}
void diff_term(struct term *a, struct term *b)
{
if (a->type != b->type) {
fprintf(stderr, "Term a: ");
print_bruijn(a);
fprintf(stderr, "\nTerm b: ");
print_bruijn(b);
fatal("\ntype mismatch %d %d\n", a->type, b->type);
}
switch (a->type) {
case ABS:
diff_term(a->u.abs.term, b->u.abs.term);
break;
case APP:
diff_term(a->u.app.lhs, b->u.app.lhs);
diff_term(a->u.app.rhs, b->u.app.rhs);
break;
case VAR:
if (a->u.var.index != b->u.var.index)
fatal("var mismatch %d=%d\n", a->u.var.index,
b->u.var.index);
break;
default:
fatal("invalid type %d\n", a->type);
}
}
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