Abstract abstractification

1 files changed, 85 insertions, 0 deletions

diff --git a/src/parse.c b/src/parse.c
new file mode 100644
index 0000000..55bcb86
--- /dev/null
+++ b/src/parse.c
@@ -0,0 +1,85 @@
+// Copyright (c) 2023, Marvin Borner <dev@marvinborner.de>
+// SPDX-License-Identifier: MIT
+
+#include <stdlib.h>
+
+#include <parse.h>
+#include <lib/hashmap.h>
+#include <map.h>
+#include <log.h>
+
+static struct term *new_term(term_type_t type)
+{
+	struct term *term = malloc(sizeof(*term));
+	if (!term)
+		fatal("out of memory!\n");
+	term->type = type;
+	return term;
+}
+
+// TODO: bit parse_bblc
+hash_t parse_blc(char **term)
+{
+	hash_t res = 0;
+	struct term *res_term = 0;
+	term_type_t res_type = 0;
+
+	if (!**term) {
+		fatal("invalid parsing state!\n");
+	} else if (**term == '0' && *(*term + 1) == '0') {
+		(*term) += 2;
+		res_type = ABS;
+		hash_t inner_hash = parse_blc(term);
+		res = hash((uint8_t *)&res_type, sizeof(res_type), inner_hash);
+
+		if ((res_term = map_get(res))) {
+			res_term->refs++;
+		} else {
+			res_term = new_term(ABS);
+			res_term->refs = 1;
+			res_term->hash = res;
+			res_term->u.abs.term = inner_hash;
+			map_set(res_term, res);
+		}
+	} else if (**term == '0' && *(*term + 1) == '1') {
+		(*term) += 2;
+		res_type = APP;
+		hash_t lhs_hash = parse_blc(term);
+		hash_t rhs_hash = parse_blc(term);
+		res = hash((uint8_t *)&res_type, sizeof(res_type), lhs_hash);
+		res = hash((uint8_t *)&res, sizeof(res), rhs_hash);
+
+		if ((res_term = map_get(res))) {
+			res_term->refs++;
+		} else {
+			res_term = new_term(res_type);
+			res_term->refs = 1;
+			res_term->hash = res;
+			res_term->u.app.lhs = lhs_hash;
+			res_term->u.app.rhs = rhs_hash;
+			map_set(res_term, res);
+		}
+	} else if (**term == '1') {
+		res_type = VAR;
+		const char *cur = *term;
+		while (**term == '1')
+			(*term)++;
+		int index = *term - cur - 1;
+		res = hash((uint8_t *)&res_type, sizeof(res_type), index);
+
+		if ((res_term = map_get(res))) {
+			res_term->refs++;
+		} else {
+			res_term = new_term(res_type);
+			res_term->refs = 1;
+			res_term->hash = res;
+			res_term->u.var.index = index;
+			map_set(res_term, res);
+		}
+		(*term)++;
+	} else {
+		(*term)++;
+		res = parse_blc(term);
+	}
+	return res;
+}