From 0290fbc2261d0585d2b394ff3448e4a19f065b1d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emmanuel=20Beno=C3=AEt?= <tseeker@nocternity.net>
Date: Mon, 2 Jan 2023 20:20:47 +0100
Subject: [PATCH] Parser - Return statement
---
src/parser.rs | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/src/parser.rs b/src/parser.rs
index e00a740..9ec561b 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -111,6 +111,7 @@ impl Parser {
/// statement := while_statement
/// statement := for_statement
/// statement := loop_control_statement
+ /// statement := return_statement
/// ```
fn parse_statement(&mut self) -> ParserResult<ast::StmtNode> {
if self.expect(&[TokenType::Var]).is_some() {
@@ -129,6 +130,8 @@ impl Parser {
self.parse_for_statement(None)
} else if let Some(lcs) = self.expect(&[TokenType::Break, TokenType::Continue]) {
self.parse_loop_control_statement(&lcs)
+ } else if let Some(ret) = self.expect(&[TokenType::Return]) {
+ self.parse_return_statement(&ret)
} else if self.expect(&[TokenType::Print]).is_some() {
let expression = self.parse_expression()?;
self.consume(&TokenType::Semicolon, "expected ';' after value")?;
@@ -426,6 +429,22 @@ impl Parser {
})
}
+ /// Parse the following rule:
+ /// ```
+ /// return_statement := "return" expression? ";"
+ /// ```
+ fn parse_return_statement(&mut self, ret_token: &Token) -> ParserResult<ast::StmtNode> {
+ let value = if self.check(&TokenType::Semicolon) {
+ None
+ } else {
+ Some(self.parse_expression()?)
+ };
+ Ok(ast::StmtNode::Return {
+ token: ret_token.clone(),
+ value,
+ })
+ }
+
/// Parse the following rule:
/// ```
/// expression := assignment