Interactive read eval loop (#409)

yash-cli/CHANGELOG-bin.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   reports a syntax error instead of treating it as a variable. For example,
   `${1abc}` and `${0_1}` are now syntax errors.
 - Improved error messages for some parameter expansion errors.
+- Interactive shells no longer exit on shell errors such as syntax errors.
 - Interactive shells now ignore the `noexec` option.
 - Interactive shells now allow modifying the trap for signals that were ignored
   on the shell startup.

yash-cli/CHANGELOG-lib.md

@@ -25,6 +25,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - The shell now executes the initialization files on startup if the shell is
   interactive.
+- Interactive shells now use `yash_semantics::interactive_read_eval_loop` instead
+  of `yash_semantics::read_eval_loop`.
 - The `bin_main` function has been renamed to `main` and its return type is now
   `!`.
 - The signature of the `startup::input::prepare_input` function has been revised

yash-cli/src/lib.rs

@@ -35,14 +35,15 @@ use futures_util::FutureExt as _;
 use std::cell::RefCell;
 use std::num::NonZeroU64;
 use std::ops::ControlFlow::{Break, Continue};
+use yash_env::option::{Interactive, On};
 use yash_env::signal;
 use yash_env::system::{Disposition, Errno};
 use yash_env::Env;
 use yash_env::RealSystem;
 use yash_env::System;
 use yash_semantics::trap::run_exit_trap;
-use yash_semantics::ExitStatus;
-use yash_semantics::{read_eval_loop, Divert};
+use yash_semantics::{interactive_read_eval_loop, read_eval_loop};
+use yash_semantics::{Divert, ExitStatus};
 use yash_syntax::parser::lex::Lexer;
 
 async fn print_version(env: &mut Env) -> ExitStatus {
@@ -71,6 +72,8 @@ async fn parse_and_print(mut env: Env) -> ExitStatus {
 
     let work = self::startup::configure_environment(&mut env, run);
 
+    let is_interactive = env.options.get(Interactive) == On;
+
     // Run initialization files
     // TODO run profile if login
     run_rcfile(&mut env, work.rcfile).await;
@@ -97,7 +100,11 @@ async fn parse_and_print(mut env: Env) -> ExitStatus {
     let mut lexer = Lexer::new(input, line, source.into());
 
     // Run the read-eval loop
-    let result = read_eval_loop(ref_env, &mut { lexer }).await;
+    let result = if is_interactive {
+        interactive_read_eval_loop(ref_env, &mut { lexer }).await
+    } else {
+        read_eval_loop(ref_env, &mut { lexer }).await
+    };
 
     env.apply_result(result);
 

yash-cli/tests/scripted_test.rs

@@ -185,6 +185,11 @@ fn error_consequences() {
     run("error-p.sh")
 }
 
+#[test]
+fn error_consequences_ex() {
+    run("error-y.sh")
+}
+
 #[test]
 fn eval_builtin() {
     run("eval-p.sh")

yash-cli/tests/scripted_test/error-p.sh

@@ -20,7 +20,6 @@ __IN__
 0
 __OUT__
 
-: TODO interactive shell not yet implemented <<\__OUT__
 test_o -d 'syntax error spares interactive shell' -i +m
 fi
 echo reached
@@ -43,7 +42,6 @@ __IN__
 0
 __OUT__
 
-: TODO interactive shell not yet implemented <<\__OUT__
 test_o -d 'expansion error spares interactive shell' -i +m
 unset a
 echo ${a?}
@@ -74,7 +72,6 @@ __IN__
 0
 __OUT__
 
-: TODO interactive shell not yet implemented <<\__OUT__
 test_o 'assignment error without command spares interactive shell' -i +m
 readonly a=a
 a=b
@@ -113,7 +110,6 @@ __OUT__
 # $1 = line no.
 # $2 = command name
 test_assign_i() {
-: TODO interactive shell not yet implemented <<\__OUT__
     testcase "$1" -d \
         "assignment error on command $2 spares interactive shell" \
         -i +m 3<<__IN__ 4<<\__OUT__ 5<&-
@@ -288,7 +284,6 @@ done
 printf 'not reached 2\n'
 __IN__
 
-: TODO interactive shell not yet implemented <<\__OUT__
 test_o 'assignment error in for loop spares interactive shell' -i +m
 readonly a=a
 for a in b
@@ -328,7 +323,6 @@ __OUT__
 # $1 = line no.
 # $2 = built-in name
 test_special_builtin_redirect_i() {
-: TODO interactive shell not yet implemented <<\__OUT__
     testcase "$1" -d \
         "redirection error on special built-in $2 spares interactive shell" \
         -i +m 3<<__IN__ 4<<\__OUT__ 5<&-