1 files changed, 63 insertions, 11 deletions

diff --git a/src/parse.c b/src/parse.c
index 18dfffe..2ef3817 100644
--- a/src/parse.c
+++ b/src/parse.c
@@ -3,33 +3,85 @@
 
 #include <stdlib.h>
 
+#include <lib/list.h>
 #include <parse.h>
 #include <log.h>
+#include <map.h>
 
-struct term *parse_blc(char **term)
+static struct term_handle abs_blc(char **term)
+{
+	term_type_t res_type = ABS;
+	struct term_handle inner = parse_blc(term);
+	hash_t res = hash((uint8_t *)&res_type, sizeof(res_type), inner.hash);
+
+	struct term *res_term;
+	if (!(res_term = map_get(res))) {
+		res_term = term_new(res_type, res);
+		res_term->u.abs.term = inner.term;
+		map_set(res_term, res);
+	}
+
+	res_term->u.abs.term->parents =
+		list_add(res_term->u.abs.term->parents, res_term);
+	return (struct term_handle){ .term = res_term, .hash = res };
+}
+
+static struct term_handle app_blc(char **term)
+{
+	term_type_t res_type = APP;
+	struct term_handle lhs = parse_blc(term);
+	struct term_handle rhs = parse_blc(term);
+
+	hash_t res = hash((uint8_t *)&res_type, sizeof(res_type), lhs.hash);
+	res = hash((uint8_t *)&res, sizeof(res), rhs.hash);
+
+	struct term *res_term;
+	if (!(res_term = map_get(res))) {
+		res_term = term_new(res_type, res);
+		res_term->u.app.lhs = lhs.term;
+		res_term->u.app.rhs = rhs.term;
+		map_set(res_term, res);
+	}
+
+	res_term->u.app.lhs->parents =
+		list_add(res_term->u.app.lhs->parents, res_term);
+	res_term->u.app.rhs->parents =
+		list_add(res_term->u.app.rhs->parents, res_term);
+	return (struct term_handle){ .term = res_term, .hash = res };
+}
+
+static struct term_handle var_blc(int index)
+{
+	term_type_t res_type = VAR;
+	hash_t res = hash((uint8_t *)&res_type, sizeof(res_type), index);
+
+	struct term *res_term;
+	if (!(res_term = map_get(res))) {
+		res_term = term_new(res_type, res);
+		res_term->u.var.index = index;
+		map_set(res_term, res);
+	}
+
+	return (struct term_handle){ .term = res_term, .hash = res };
+}
+
+struct term_handle parse_blc(char **term)
 {
 	if (!**term) {
 		fatal("invalid parsing state!\n");
 	} else if (**term == '0' && *(*term + 1) == '0') {
 		(*term) += 2;
-		struct term *new = term_new(ABS);
-		new->u.abs.term = parse_blc(term);
-		return new;
+		return abs_blc(term);
 	} else if (**term == '0' && *(*term + 1) == '1') {
 		(*term) += 2;
-		struct term *new = term_new(APP);
-		new->u.app.lhs = parse_blc(term);
-		new->u.app.rhs = parse_blc(term);
-		return new;
+		return app_blc(term);
 	} else if (**term == '1') {
 		const char *cur = *term;
 		while (**term == '1')
 			(*term)++;
 		int index = *term - cur - 1;
 		(*term)++;
-		struct term *new = term_new(VAR);
-		new->u.var.index = index;
-		return new;
+		return var_blc(index);
 	} else {
 		(*term)++;
 		return parse_blc(term);