From 89c7bb5253ce4d64bc604ed43d63b3493db2efba Mon Sep 17 00:00:00 2001
From: omicron <omicron.me@protonmail.com>
Date: Tue, 1 Apr 2025 20:03:28 +0200
Subject: [PATCH] Add basic parser utilities

---
 src/parser_util.c | 31 +++++++++++++++++++++++++++++++
 src/parser_util.h | 22 ++++++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 src/parser_util.c
 create mode 100644 src/parser_util.h

diff --git a/src/parser_util.c b/src/parser_util.c
new file mode 100644
index 0000000..1ece241
--- /dev/null
+++ b/src/parser_util.c
@@ -0,0 +1,31 @@
+#include "parser_util.h"
+
+error_t *err_parse_no_match =
+    &(error_t){.message = "parsing failed to find the correct token sequence"};
+
+parse_result_t parse_error(error_t *err) {
+    return (parse_result_t){.err = err};
+}
+
+parse_result_t parse_no_match() {
+    return parse_error(err_parse_no_match);
+}
+
+parse_result_t parse_success(ast_node_t *ast, tokenlist_entry_t *next) {
+    return (parse_result_t){.node = ast, .next = next};
+}
+
+parse_result_t parse_token(tokenlist_entry_t *current,
+                           lexer_token_id_t token_id, node_id_t ast_id) {
+    if (current->token.id != token_id)
+        return parse_no_match();
+
+    ast_node_t *node;
+    error_t *err = ast_node_alloc(&node);
+    if (err)
+        return parse_error(err);
+    node->id = ast_id;
+    node->token_entry = current;
+
+    return parse_success(node, current->next);
+}
diff --git a/src/parser_util.h b/src/parser_util.h
new file mode 100644
index 0000000..c081ef3
--- /dev/null
+++ b/src/parser_util.h
@@ -0,0 +1,22 @@
+#ifndef INCLUDE_SRC_PARSER_UTIL_H_
+#define INCLUDE_SRC_PARSER_UTIL_H_
+
+#include "ast.h"
+#include "error.h"
+#include "tokenlist.h"
+
+typedef struct parse_result {
+    error_t *err;
+    tokenlist_entry_t *next;
+    ast_node_t *node;
+} parse_result_t;
+
+parse_result_t parse_error(error_t *err);
+parse_result_t parse_no_match();
+parse_result_t parse_success(ast_node_t *ast, tokenlist_entry_t *next);
+parse_result_t parse_token(tokenlist_entry_t *current,
+                           lexer_token_id_t token_id, node_id_t ast_id);
+
+tokenlist_entry_t *skip_insignificant(tokenlist_entry_t *);
+
+#endif // INCLUDE_SRC_PARSER_UTIL_H_