lang: replace stack-based parser with a recursive parser

lang/parse/ctx.c

@@ -0,0 +1,126 @@
+#include "ctx.h"
+
+#include <ivy/lang/parse.h>
+#include <stdlib.h>
+#include <string.h>
+
+enum ivy_status ivy_parser_create(struct ivy_parser **parser)
+{
+	struct ivy_parser *out = malloc(sizeof *out);
+	if (!out) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(out, 0x0, sizeof *out);
+
+	*parser = out;
+	return IVY_OK;
+}
+
+void ivy_parser_destroy(struct ivy_parser *parser)
+{
+	free(parser);
+}
+
+enum ivy_status ivy_parser_set_diag_ctx(
+	struct ivy_parser *parser, struct ivy_diag_ctx *ctx)
+{
+	parser->p_diag = ctx;
+	return IVY_OK;
+}
+
+enum ivy_status ivy_parser_get_status(struct ivy_parser *parser)
+{
+	return parser->p_status;
+}
+
+enum ivy_status ivy_parser_parse(
+	struct ivy_parser *parser, struct ivy_lexer *src, struct ivy_ast_node **out)
+{
+	parser->p_src = src;
+	enum ivy_status status = parse_unit(parser, out);
+	if (status == IVY_ERR_EOF && *out != NULL) {
+		status = IVY_OK;
+	}
+
+	return status;
+}
+
+struct ivy_token *peek_token(struct ivy_parser *parser)
+{
+	fx_queue_entry *entry = fx_queue_first(&parser->p_tokens);
+	if (!entry) {
+		return ivy_lexer_peek(parser->p_src);
+	}
+
+	return fx_unbox(struct ivy_token, entry, t_entry);
+}
+
+struct ivy_token *peek_next_token(struct ivy_parser *parser)
+{
+	if (fx_queue_empty(&parser->p_tokens)) {
+		struct ivy_token *tok = parse_token(parser);
+		fx_queue_push_back(&parser->p_tokens, &tok->t_entry);
+		return ivy_lexer_peek(parser->p_src);
+	}
+
+	fx_queue_entry *buf = fx_queue_first(&parser->p_tokens);
+	if (buf) {
+		buf = fx_queue_next(buf);
+	}
+
+	if (buf) {
+		return fx_unbox(struct ivy_token, buf, t_entry);
+	}
+
+	return ivy_lexer_peek(parser->p_src);
+}
+
+struct ivy_token *parse_token(struct ivy_parser *parser)
+{
+	fx_queue_entry *entry = fx_queue_pop_front(&parser->p_tokens);
+	if (!entry) {
+		return ivy_lexer_read(parser->p_src);
+	}
+
+	return fx_unbox(struct ivy_token, entry, t_entry);
+}
+
+void discard_token(struct ivy_parser *parser)
+{
+	struct ivy_token *tok = parse_token(parser);
+	if (tok) {
+		ivy_token_destroy(tok);
+	}
+}
+
+void __parse_trace(
+	struct ivy_parser *parser, const char *func, int line,
+	const char *format, ...)
+{
+	struct ivy_token *tok = NULL;
+	if (parser) {
+		tok = peek_token(parser);
+		if (tok) {
+			fprintf(stderr, "[%zu:%zu] ", tok->t_start.c_row,
+			        tok->t_start.c_col);
+		} else {
+			fprintf(stderr, "[EOF] ");
+		}
+	} else {
+		fprintf(stderr, "[UNK] ");
+	}
+
+	fprintf(stderr, "%s:%d: ", func, line);
+
+	if (tok) {
+		fprintf(stderr, "(%s) ", ivy_token_to_string(tok));
+	}
+
+	va_list va;
+	va_start(va, format);
+	vfprintf(stderr, format, va);
+	va_end(va);
+
+	fputc('\n', stderr);
+}