bshell/bshell.runtime/parse/syntax/func.c

#include "../syntax.h"

bool parse_func(struct bshell_parse_ctx *ctx, struct bshell_ast_node **out)
{
	if (!parse_keyword(ctx, BSHELL_KW_FUNC)) {
		return false;
	}

	struct bshell_lex_token *name = NULL;
	if (!parse_word(ctx, &name)) {
		report_error(ctx, "expected function identifier");
		return false;
	}

	struct bshell_func_ast_node *func
		= (struct bshell_func_ast_node *)bshell_ast_node_create(
			BSHELL_AST_FUNC);
	if (!func) {
		ctx->p_status = BSHELL_ERR_NO_MEMORY;
		bshell_lex_token_destroy(name);
		return false;
	}

	func->n_name = name;

	if (!parse_symbol(ctx, BSHELL_SYM_LEFT_PAREN)) {
		report_error(ctx, "expected `(` after function identifier");
		bshell_ast_node_destroy((struct bshell_ast_node *)func);
		return false;
	}

	size_t nr_args = 0;
	bool ok = true;
	while (1) {
		if (parse_symbol(ctx, BSHELL_SYM_RIGHT_PAREN)) {
			break;
		}

		if (nr_args > 0 && !parse_symbol(ctx, BSHELL_SYM_COMMA)) {
			report_error(
				ctx,
				"expected `,` or `)` after parameter name");
			ok = false;
			break;
		}

		struct bshell_lex_token *param_token = NULL;
		struct bshell_var_ast_node *param_node = NULL;
		if (!parse_var(ctx, &param_token)) {
			report_error(ctx, "expected parameter variable");
			ok = false;
			break;
		}

		param_node
			= (struct bshell_var_ast_node *)bshell_ast_node_create(
				BSHELL_AST_VAR);
		if (!param_node) {
			ok = false;
			ctx->p_status = BSHELL_ERR_NO_MEMORY;
			bshell_lex_token_destroy(param_token);
			break;
		}

		param_node->n_ident = param_token;
		fx_queue_push_back(
			&func->n_params,
			&param_node->n_base.n_entry);
	}

	if (!ok) {
		if (ctx->p_status == BSHELL_SUCCESS) {
			ctx->p_status = BSHELL_ERR_BAD_SYNTAX;
		}

		bshell_ast_node_destroy((struct bshell_ast_node *)func);
		return false;
	}

	if (!parse_block(ctx, &func->n_body)) {
		report_error(ctx, "failed to parse function body");
		bshell_ast_node_destroy((struct bshell_ast_node *)func);
		return false;
	}

	*out = (struct bshell_ast_node *)func;
	return true;
}