From cac3bbd732014bee392ac8a098fb371c2c650325 Mon Sep 17 00:00:00 2001
From: Per Lindgren <per.lindgren@ltu.se>
Date: Sun, 13 Sep 2020 13:32:07 +0200
Subject: [PATCH] fallible iterator
---
src/ast/main.rs | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/src/ast/main.rs b/src/ast/main.rs
index 4b310e9..825a7ff 100644
--- a/src/ast/main.rs
+++ b/src/ast/main.rs
@@ -31,17 +31,18 @@ fn parse_num_or_id() {
type Error = String;
fn type_check(stmts: &Stmts) -> Result<(), Error> {
- for i in stmts {
- match i {
- Stmt::Let(_, _) => {
- println!("let");
- }
- Stmt::If(_, _, __) => {
- println!("if");
- }
+ let r: Result<(), Error> = stmts.iter().try_for_each(|i| match i {
+ Stmt::Let(_, _) => {
+ println!("let");
+ Ok(())
}
- }
- Ok(())
+ Stmt::If(_, _, __) => {
+ println!("if");
+ Err("error in if".to_string())?
+ }
+ });
+ println!("here we can do something before returning");
+ r
}
#[test]
@@ -49,6 +50,7 @@ fn test_stmts() {
let stmts = vec![
Stmt::Let("a".to_string(), NumOrId::Num(1)),
Stmt::Let("b".to_string(), NumOrId::Num(2)),
+ Stmt::If("b".to_string(), Stmts::new(), None),
Stmt::Let("c".to_string(), NumOrId::Num(3)),
];
type_check(&stmts).unwrap();
--
GitLab