Reorganize repl modules

Cargo.lock

@@ -3236,6 +3236,7 @@ dependencies = [
  "roc_cli",
  "roc_repl_cli",
  "roc_test_utils",
+ "rustyline",
  "strip-ansi-escapes",
  "wasmer",
  "wasmer-wasi",

crates/cli/src/main.rs

@@ -177,14 +177,7 @@ fn main() -> io::Result<()> {
                 }
             }
         }
-        Some((CMD_REPL, _)) => {
+        Some((CMD_REPL, _)) => Ok(roc_repl_cli::main()),
-            {
-                roc_repl_cli::main()?;
-
-                // Exit 0 if the repl exited normally
-                Ok(0)
-            }
-        }
         Some((CMD_EDIT, matches)) => {
             match matches
                 .values_of_os(DIRECTORY_OR_FILES)

crates/repl_cli/src/cli_gen.rs

@@ -0,0 +1,270 @@
+use bumpalo::Bump;
+use inkwell::context::Context;
+use libloading::Library;
+use roc_build::link::llvm_module_to_dylib;
+use roc_collections::all::MutSet;
+use roc_gen_llvm::llvm::build::LlvmBackendMode;
+use roc_gen_llvm::llvm::externs::add_default_roc_externs;
+use roc_gen_llvm::{run_jit_function, run_jit_function_dynamic_type};
+use roc_intern::SingleThreadedInterner;
+use roc_load::{EntryPoint, MonomorphizedModule};
+use roc_mono::ir::OptLevel;
+use roc_mono::layout::Layout;
+use roc_parse::ast::Expr;
+use roc_parse::parser::SyntaxError;
+use roc_repl_eval::eval::jit_to_ast;
+use roc_repl_eval::gen::{compile_to_mono, format_answer, ReplOutput};
+use roc_repl_eval::{ReplApp, ReplAppMemory};
+use roc_reporting::report::DEFAULT_PALETTE;
+use roc_std::RocStr;
+use roc_target::TargetInfo;
+use roc_types::pretty_print::{name_and_print_var, DebugPrint};
+use roc_types::subs::Subs;
+use target_lexicon::Triple;
+
+pub fn gen_and_eval_llvm<'a>(
+    src: &str,
+    target: Triple,
+    opt_level: OptLevel,
+    val_name: String,
+) -> Result<ReplOutput, SyntaxError<'a>> {
+    let arena = Bump::new();
+    let target_info = TargetInfo::from(&target);
+
+    let mut loaded = match compile_to_mono(&arena, src, target_info, DEFAULT_PALETTE) {
+        Ok(x) => x,
+        Err(prob_strings) => {
+            return Ok(ReplOutput::Problems(prob_strings));
+        }
+    };
+
+    debug_assert_eq!(loaded.exposed_to_host.values.len(), 1);
+    let (main_fn_symbol, main_fn_var) = loaded.exposed_to_host.values.iter().next().unwrap();
+    let main_fn_symbol = *main_fn_symbol;
+    let main_fn_var = *main_fn_var;
+
+    // pretty-print the expr type string for later.
+    let expr_type_str = name_and_print_var(
+        main_fn_var,
+        &mut loaded.subs,
+        loaded.module_id,
+        &loaded.interns,
+        DebugPrint::NOTHING,
+    );
+
+    let (_, main_fn_layout) = match loaded.procedures.keys().find(|(s, _)| *s == main_fn_symbol) {
+        Some(layout) => *layout,
+        None => {
+            return Ok(ReplOutput::NoProblems {
+                expr: "<function>".to_string(),
+                expr_type: expr_type_str,
+                val_name,
+            });
+        }
+    };
+
+    let interns = loaded.interns.clone();
+
+    let (lib, main_fn_name, subs, layout_interner) =
+        mono_module_to_dylib(&arena, target, loaded, opt_level).expect("we produce a valid Dylib");
+
+    let mut app = CliApp { lib };
+
+    let res_answer = jit_to_ast(
+        &arena,
+        &mut app,
+        main_fn_name,
+        main_fn_layout,
+        main_fn_var,
+        &subs,
+        &interns,
+        layout_interner.into_global().fork(),
+        target_info,
+    );
+
+    Ok(format_answer(&arena, res_answer, expr_type_str, val_name))
+}
+
+struct CliApp {
+    lib: Library,
+}
+
+struct CliMemory;
+
+impl<'a> ReplApp<'a> for CliApp {
+    type Memory = CliMemory;
+
+    /// Run user code that returns a type with a `Builtin` layout
+    /// Size of the return value is statically determined from its Rust type
+    fn call_function<Return, F>(&mut self, main_fn_name: &str, mut transform: F) -> Expr<'a>
+    where
+        F: FnMut(&'a Self::Memory, Return) -> Expr<'a>,
+        Self::Memory: 'a,
+    {
+        run_jit_function!(self.lib, main_fn_name, Return, |v| transform(&CliMemory, v))
+    }
+
+    /// Run user code that returns a struct or union, whose size is provided as an argument
+    fn call_function_dynamic_size<T, F>(
+        &mut self,
+        main_fn_name: &str,
+        ret_bytes: usize,
+        mut transform: F,
+    ) -> T
+    where
+        F: FnMut(&'a Self::Memory, usize) -> T,
+        Self::Memory: 'a,
+    {
+        run_jit_function_dynamic_type!(self.lib, main_fn_name, ret_bytes, |v| transform(
+            &CliMemory, v
+        ))
+    }
+}
+
+macro_rules! deref_number {
+    ($name: ident, $t: ty) => {
+        fn $name(&self, addr: usize) -> $t {
+            let ptr = addr as *const _;
+            unsafe { *ptr }
+        }
+    };
+}
+
+impl ReplAppMemory for CliMemory {
+    deref_number!(deref_bool, bool);
+
+    deref_number!(deref_u8, u8);
+    deref_number!(deref_u16, u16);
+    deref_number!(deref_u32, u32);
+    deref_number!(deref_u64, u64);
+    deref_number!(deref_u128, u128);
+    deref_number!(deref_usize, usize);
+
+    deref_number!(deref_i8, i8);
+    deref_number!(deref_i16, i16);
+    deref_number!(deref_i32, i32);
+    deref_number!(deref_i64, i64);
+    deref_number!(deref_i128, i128);
+    deref_number!(deref_isize, isize);
+
+    deref_number!(deref_f32, f32);
+    deref_number!(deref_f64, f64);
+
+    fn deref_str(&self, addr: usize) -> &str {
+        let reference: &RocStr = unsafe { std::mem::transmute(addr) };
+        reference.as_str()
+    }
+
+    fn deref_pointer_with_tag_id(&self, addr: usize) -> (u16, u64) {
+        let addr_with_id = self.deref_usize(addr);
+        let tag_id_mask = 0b111;
+
+        let tag_id = addr_with_id & tag_id_mask;
+        let data_addr = addr_with_id & !tag_id_mask;
+        (tag_id as _, data_addr as _)
+    }
+}
+
+fn mono_module_to_dylib<'a>(
+    arena: &'a Bump,
+    target: Triple,
+    loaded: MonomorphizedModule<'a>,
+    opt_level: OptLevel,
+) -> Result<
+    (
+        libloading::Library,
+        &'a str,
+        Subs,
+        SingleThreadedInterner<'a, Layout<'a>>,
+    ),
+    libloading::Error,
+> {
+    let target_info = TargetInfo::from(&target);
+
+    let MonomorphizedModule {
+        procedures,
+        entry_point,
+        interns,
+        subs,
+        layout_interner,
+        ..
+    } = loaded;
+
+    let context = Context::create();
+    let builder = context.create_builder();
+    let module = arena.alloc(roc_gen_llvm::llvm::build::module_from_builtins(
+        &target, &context, "",
+    ));
+
+    let module = arena.alloc(module);
+    let (module_pass, function_pass) =
+        roc_gen_llvm::llvm::build::construct_optimization_passes(module, opt_level);
+
+    let (dibuilder, compile_unit) = roc_gen_llvm::llvm::build::Env::new_debug_info(module);
+
+    // Compile and add all the Procs before adding main
+    let env = roc_gen_llvm::llvm::build::Env {
+        arena,
+        layout_interner: &layout_interner,
+        builder: &builder,
+        dibuilder: &dibuilder,
+        compile_unit: &compile_unit,
+        context: &context,
+        interns,
+        module,
+        target_info,
+        mode: LlvmBackendMode::GenTest, // so roc_panic is generated
+        // important! we don't want any procedures to get the C calling convention
+        exposed_to_host: MutSet::default(),
+    };
+
+    // Add roc_alloc, roc_realloc, and roc_dealloc, since the repl has no
+    // platform to provide them.
+    add_default_roc_externs(&env);
+
+    let entry_point = match entry_point {
+        EntryPoint::Executable { symbol, layout, .. } => {
+            roc_mono::ir::EntryPoint { symbol, layout }
+        }
+        EntryPoint::Test => {
+            unreachable!()
+        }
+    };
+
+    let (main_fn_name, main_fn) = roc_gen_llvm::llvm::build::build_procedures_return_main(
+        &env,
+        opt_level,
+        procedures,
+        entry_point,
+    );
+
+    env.dibuilder.finalize();
+
+    // we don't use the debug info, and it causes weird errors.
+    module.strip_debug_info();
+
+    // Uncomment this to see the module's un-optimized LLVM instruction output:
+    // env.module.print_to_stderr();
+
+    if main_fn.verify(true) {
+        function_pass.run_on(&main_fn);
+    } else {
+        panic!("Main function {} failed LLVM verification in build. Uncomment things nearby to see more details.", main_fn_name);
+    }
+
+    module_pass.run_on(env.module);
+
+    // Uncomment this to see the module's optimized LLVM instruction output:
+    // env.module.print_to_stderr();
+
+    // Verify the module
+    if let Err(errors) = env.module.verify() {
+        panic!(
+            "Errors defining module:\n{}\n\nUncomment things nearby to see more details.",
+            errors.to_string()
+        );
+    }
+
+    llvm_module_to_dylib(env.module, &target, opt_level)
+        .map(|lib| (lib, main_fn_name, subs, layout_interner))
+}

crates/repl_cli/src/lib.rs

@@ -1,28 +1,12 @@
+mod cli_gen;
 mod colors;
-mod repl_state;
+pub mod repl_state;
-
-use bumpalo::Bump;
-use const_format::concatcp;
-use inkwell::context::Context;
-use libloading::Library;
-use repl_state::ReplState;
-use roc_gen_llvm::llvm::build::LlvmBackendMode;
-use roc_intern::SingleThreadedInterner;
-use roc_mono::layout::Layout;
-use roc_types::subs::Subs;
-use target_lexicon::Triple;
 
 use colors::{BLUE, END_COL, PINK};
-use roc_build::link::llvm_module_to_dylib;
+use const_format::concatcp;
-use roc_collections::all::MutSet;
+use repl_state::ReplState;
-use roc_gen_llvm::llvm::externs::add_default_roc_externs;
+
-use roc_gen_llvm::{run_jit_function, run_jit_function_dynamic_type};
+use crate::repl_state::PROMPT;
-use roc_load::{EntryPoint, MonomorphizedModule};
-use roc_mono::ir::OptLevel;
-use roc_parse::ast::Expr;
-use roc_repl_eval::{ReplApp, ReplAppMemory};
-use roc_std::RocStr;
-use roc_target::TargetInfo;
 
 pub const WELCOME_MESSAGE: &str = concatcp!(
     "\n  The rockin’ ",
@@ -38,194 +22,7 @@ pub const WELCOME_MESSAGE: &str = concatcp!(
 
 // For when nothing is entered in the repl
 // TODO add link to repl tutorial(does not yet exist).
-pub const SHORT_INSTRUCTIONS: &str = "Enter an expression, or :help, or :q to quit.\n";
+const SHORT_INSTRUCTIONS: &str = "Enter an expression, or :help, or :q to quit.\n";
-
-pub const PROMPT: &str = concatcp!("\n", BLUE, "»", END_COL, " ");
-pub const CONT_PROMPT: &str = concatcp!(BLUE, "…", END_COL, " ");
-
-struct CliApp {
-    lib: Library,
-}
-
-struct CliMemory;
-
-impl<'a> ReplApp<'a> for CliApp {
-    type Memory = CliMemory;
-
-    /// Run user code that returns a type with a `Builtin` layout
-    /// Size of the return value is statically determined from its Rust type
-    fn call_function<Return, F>(&mut self, main_fn_name: &str, mut transform: F) -> Expr<'a>
-    where
-        F: FnMut(&'a Self::Memory, Return) -> Expr<'a>,
-        Self::Memory: 'a,
-    {
-        run_jit_function!(self.lib, main_fn_name, Return, |v| transform(&CliMemory, v))
-    }
-
-    /// Run user code that returns a struct or union, whose size is provided as an argument
-    fn call_function_dynamic_size<T, F>(
-        &mut self,
-        main_fn_name: &str,
-        ret_bytes: usize,
-        mut transform: F,
-    ) -> T
-    where
-        F: FnMut(&'a Self::Memory, usize) -> T,
-        Self::Memory: 'a,
-    {
-        run_jit_function_dynamic_type!(self.lib, main_fn_name, ret_bytes, |v| transform(
-            &CliMemory, v
-        ))
-    }
-}
-
-macro_rules! deref_number {
-    ($name: ident, $t: ty) => {
-        fn $name(&self, addr: usize) -> $t {
-            let ptr = addr as *const _;
-            unsafe { *ptr }
-        }
-    };
-}
-
-impl ReplAppMemory for CliMemory {
-    deref_number!(deref_bool, bool);
-
-    deref_number!(deref_u8, u8);
-    deref_number!(deref_u16, u16);
-    deref_number!(deref_u32, u32);
-    deref_number!(deref_u64, u64);
-    deref_number!(deref_u128, u128);
-    deref_number!(deref_usize, usize);
-
-    deref_number!(deref_i8, i8);
-    deref_number!(deref_i16, i16);
-    deref_number!(deref_i32, i32);
-    deref_number!(deref_i64, i64);
-    deref_number!(deref_i128, i128);
-    deref_number!(deref_isize, isize);
-
-    deref_number!(deref_f32, f32);
-    deref_number!(deref_f64, f64);
-
-    fn deref_str(&self, addr: usize) -> &str {
-        let reference: &RocStr = unsafe { std::mem::transmute(addr) };
-        reference.as_str()
-    }
-
-    fn deref_pointer_with_tag_id(&self, addr: usize) -> (u16, u64) {
-        let addr_with_id = self.deref_usize(addr);
-        let tag_id_mask = 0b111;
-
-        let tag_id = addr_with_id & tag_id_mask;
-        let data_addr = addr_with_id & !tag_id_mask;
-        (tag_id as _, data_addr as _)
-    }
-}
-
-pub fn mono_module_to_dylib<'a>(
-    arena: &'a Bump,
-    target: Triple,
-    loaded: MonomorphizedModule<'a>,
-    opt_level: OptLevel,
-) -> Result<
-    (
-        libloading::Library,
-        &'a str,
-        Subs,
-        SingleThreadedInterner<'a, Layout<'a>>,
-    ),
-    libloading::Error,
-> {
-    let target_info = TargetInfo::from(&target);
-
-    let MonomorphizedModule {
-        procedures,
-        entry_point,
-        interns,
-        subs,
-        layout_interner,
-        ..
-    } = loaded;
-
-    let context = Context::create();
-    let builder = context.create_builder();
-    let module = arena.alloc(roc_gen_llvm::llvm::build::module_from_builtins(
-        &target, &context, "",
-    ));
-
-    let module = arena.alloc(module);
-    let (module_pass, function_pass) =
-        roc_gen_llvm::llvm::build::construct_optimization_passes(module, opt_level);
-
-    let (dibuilder, compile_unit) = roc_gen_llvm::llvm::build::Env::new_debug_info(module);
-
-    // Compile and add all the Procs before adding main
-    let env = roc_gen_llvm::llvm::build::Env {
-        arena,
-        layout_interner: &layout_interner,
-        builder: &builder,
-        dibuilder: &dibuilder,
-        compile_unit: &compile_unit,
-        context: &context,
-        interns,
-        module,
-        target_info,
-        mode: LlvmBackendMode::GenTest, // so roc_panic is generated
-        // important! we don't want any procedures to get the C calling convention
-        exposed_to_host: MutSet::default(),
-    };
-
-    // Add roc_alloc, roc_realloc, and roc_dealloc, since the repl has no
-    // platform to provide them.
-    add_default_roc_externs(&env);
-
-    let entry_point = match entry_point {
-        EntryPoint::Executable { symbol, layout, .. } => {
-            roc_mono::ir::EntryPoint { symbol, layout }
-        }
-        EntryPoint::Test => {
-            unreachable!()
-        }
-    };
-
-    let (main_fn_name, main_fn) = roc_gen_llvm::llvm::build::build_procedures_return_main(
-        &env,
-        opt_level,
-        procedures,
-        entry_point,
-    );
-
-    env.dibuilder.finalize();
-
-    // we don't use the debug info, and it causes weird errors.
-    module.strip_debug_info();
-
-    // Uncomment this to see the module's un-optimized LLVM instruction output:
-    // env.module.print_to_stderr();
-
-    if main_fn.verify(true) {
-        function_pass.run_on(&main_fn);
-    } else {
-        panic!("Main function {} failed LLVM verification in build. Uncomment things nearby to see more details.", main_fn_name);
-    }
-
-    module_pass.run_on(env.module);
-
-    // Uncomment this to see the module's optimized LLVM instruction output:
-    // env.module.print_to_stderr();
-
-    // Verify the module
-    if let Err(errors) = env.module.verify() {
-        panic!(
-            "Errors defining module:\n{}\n\nUncomment things nearby to see more details.",
-            errors.to_string()
-        );
-    }
-
-    llvm_module_to_dylib(env.module, &target, opt_level)
-        .map(|lib| (lib, main_fn_name, subs, layout_interner))
-}
 
 pub fn main() -> i32 {
     use rustyline::error::ReadlineError;
@@ -250,11 +47,13 @@ pub fn main() -> i32 {
 
                 let repl_helper = editor.helper_mut().expect("Editor helper was not set");
 
-                dbg!(&editor);
+                match repl_helper.step(trim_line) {
-
-                match step_repl_state(repl_helper, trim_line) {
                     Ok(output) => {
-                        print!("{}", output);
+                        // If there was no output, don't print a blank line!
+                        // (This happens for something like a type annotation.)
+                        if !output.is_empty() {
+                            println!("{}", output);
+                        }
                     }
                     Err(exit_code) => return exit_code,
                 };

crates/repl_cli/src/repl_state.rs

@@ -1,20 +1,23 @@
-use crate::colors::{BLUE, END_COL, PINK};
+use crate::cli_gen::gen_and_eval_llvm;
+use crate::colors::{BLUE, END_COL, GREEN, PINK};
 use bumpalo::Bump;
 use const_format::concatcp;
-use roc_parse::ast::ValueDef;
+use roc_mono::ir::OptLevel;
-use roc_parse::expr::{parse_single_def, ExprParseOptions};
+use roc_parse::ast::{Expr, TypeDef, ValueDef};
-use roc_parse::parser::{EClosure, EExpr, Parser};
+use roc_parse::expr::{parse_single_def, ExprParseOptions, SingleDef};
+use roc_parse::parser::{EClosure, EExpr};
 use roc_parse::parser::{Either, SyntaxError};
 use roc_parse::state::State;
-use roc_repl_eval::eval::jit_to_ast;
+use roc_repl_eval::gen::ReplOutput;
-use roc_repl_eval::gen::{compile_to_mono, format_answer, ReplOutput};
-use roc_reporting::report::DEFAULT_PALETTE;
-use roc_types::pretty_print::{name_and_print_var, DebugPrint};
 use rustyline::highlight::{Highlighter, PromptInfo};
 use rustyline::validate::{self, ValidationContext, ValidationResult, Validator};
 use rustyline_derive::{Completer, Helper, Hinter};
 use std::borrow::Cow;
 use std::collections::LinkedList;
+use target_lexicon::Triple;
+
+pub const PROMPT: &str = concatcp!("\n", BLUE, "»", END_COL, " ");
+pub const CONT_PROMPT: &str = concatcp!(BLUE, "…", END_COL, " ");
 
 // TODO add link to repl tutorial(does not yet exist).
 pub const TIPS: &str = concatcp!(
@@ -39,17 +42,17 @@ pub const TIPS: &str = concatcp!(
     ":help\n"
 );
 
-pub struct PastDef {
+struct PastDef {
-    ident: String,
+    _ident: String,
-    src: String,
+    _src: String,
 }
 
 #[derive(Completer, Helper, Hinter)]
-pub(crate) struct ReplState {
+pub struct ReplState {
     validator: InputValidator,
     prev_line_blank: bool,
     pending_src: String,
-    past_defs: LinkedList<PastDef>,
+    _past_defs: LinkedList<PastDef>,
 }
 
 impl ReplState {
@@ -58,11 +61,11 @@ impl ReplState {
             validator: InputValidator::new(),
             prev_line_blank: false,
             pending_src: String::new(),
-            past_defs: Default::default(),
+            _past_defs: Default::default(),
         }
     }
 
-    fn step(&mut self, trim_line: &str) -> Result<String, i32> {
+    pub fn step(&mut self, trim_line: &str) -> Result<String, i32> {
         match trim_line.to_lowercase().as_str() {
             "" => {
                 if self.pending_src.is_empty() {
@@ -114,24 +117,12 @@ impl ReplState {
             self.pending_src.as_str()
         };
 
-        dbg!(&src);
+        let arena = Bump::new();
 
-        // First, try to parse it as a Def. If that succeeds, record it in self and continue.
+        let src = match parse_src(&arena, src) {
-        let src = match parse_single_def(
+            ParseOutcome::Expr(_) => src,
-            ExprParseOptions {
+            ParseOutcome::ValueDef(value_def) => {
-                accept_multi_backpassing: true,
+                match value_def {
-                check_for_arrow: true,
-            },
-            0,
-            &Bump::new(),
-            State::new(src.as_bytes()),
-        ) {
-            Ok((_, Some(single_def), _)) => match single_def.type_or_value {
-                Either::First(type_def) => {
-                    // Alias, Opaque, or Ability
-                    todo!("handle Alias, Opaque, or Ability")
-                }
-                Either::Second(value_def) => match value_def {
                     ValueDef::Annotation(_, _) => {
                         // Needed to avoid a borrow error.
                         let src = src.to_string();
@@ -145,13 +136,13 @@ impl ReplState {
                         self.pending_src.push_str(src.as_str());
                         self.pending_src.push('\n');
 
-                        // Return without clearing pending_src.
+                        // Return without running eval or clearing pending_src.
                         return Ok(String::new());
                     }
-                    ValueDef::Body(loc_pattern, loc_expr)
+                    ValueDef::Body(_loc_pattern, _loc_expr)
                     | ValueDef::AnnotatedBody {
-                        body_pattern: loc_pattern,
+                        body_pattern: _loc_pattern,
-                        body_expr: loc_expr,
+                        body_expr: _loc_expr,
                         ..
                     } => todo!("handle receiving a toplevel def of a value/function"),
                     ValueDef::Expect { .. } => {
@@ -160,12 +151,13 @@ impl ReplState {
                     ValueDef::ExpectFx { .. } => {
                         todo!("handle receiving an `expect-fx` - what should the repl do for that?")
                     }
-                },
+                }
-            },
-            Ok(_) => src,
-            Err((_, eexpr, _)) => {
-                return Err(fail);
             }
+            ParseOutcome::TypeDef(_) => {
+                // Alias, Opaque, or Ability
+                todo!("handle Alias, Opaque, or Ability")
+            }
+            ParseOutcome::Incomplete => todo!(),
         };
 
         let answer = gen_and_eval_llvm(
@@ -182,11 +174,11 @@ impl ReplState {
     }
 
     /// Wrap the given expresssion in the appropriate past defs
-    fn wrapped_expr_src(&self, src: &str) -> String {
+    fn _wrapped_expr_src(&self, src: &str) -> String {
         let mut buf = String::new();
 
-        for past_def in self.past_defs.iter() {
+        for past_def in self._past_defs.iter() {
-            buf.push_str(past_def.src.as_str());
+            buf.push_str(past_def._src.as_str());
             buf.push('\n');
         }
 
@@ -196,6 +188,58 @@ impl ReplState {
     }
 }
 
+enum ParseOutcome<'a> {
+    ValueDef(ValueDef<'a>),
+    TypeDef(TypeDef<'a>),
+    Expr(Expr<'a>),
+    Incomplete,
+}
+
+fn parse_src<'a>(arena: &'a Bump, src: &'a str) -> ParseOutcome<'a> {
+    let src_bytes = src.trim().as_bytes();
+
+    match roc_parse::expr::parse_loc_expr(0, &arena, State::new(src_bytes)) {
+        Ok((_, loc_expr, _)) => ParseOutcome::Expr(loc_expr.value),
+        // Special case some syntax errors to allow for multi-line inputs
+        Err((_, EExpr::Closure(EClosure::Body(_, _), _), _)) => ParseOutcome::Incomplete,
+        Err((_, EExpr::DefMissingFinalExpr(_), _))
+        | Err((_, EExpr::DefMissingFinalExpr2(_, _), _)) => {
+            // This indicates that we had an attempted def; re-parse it as a single-line def.
+            match parse_single_def(
+                ExprParseOptions {
+                    accept_multi_backpassing: true,
+                    check_for_arrow: true,
+                },
+                0,
+                &arena,
+                State::new(src_bytes),
+            ) {
+                Ok((
+                    _,
+                    Some(SingleDef {
+                        type_or_value: Either::First(type_def),
+                        ..
+                    }),
+                    _,
+                )) => ParseOutcome::TypeDef(type_def),
+                Ok((
+                    _,
+                    Some(SingleDef {
+                        type_or_value: Either::Second(value_def),
+                        ..
+                    }),
+                    _,
+                )) => ParseOutcome::ValueDef(value_def),
+                Ok((_, None, _)) => {
+                    todo!("TODO determine appropriate ParseOutcome for Ok(None)")
+                }
+                Err(_) => ParseOutcome::Incomplete,
+            }
+        }
+        Err(_) => ParseOutcome::Incomplete,
+    }
+}
+
 struct InputValidator {}
 
 impl InputValidator {
@@ -206,36 +250,26 @@ impl InputValidator {
 
 impl Validator for InputValidator {
     fn validate(&self, ctx: &mut ValidationContext) -> rustyline::Result<ValidationResult> {
-        if ctx.input().is_empty() {
+        validate(ctx.input())
-            Ok(ValidationResult::Incomplete)
+    }
-        } else {
+}
-            let arena = bumpalo::Bump::new();
-            let state = roc_parse::state::State::new(ctx.input().trim().as_bytes());
-            let answer = match roc_parse::expr::toplevel_defs(0).parse(&arena, state) {
-                // Special case some syntax errors to allow for multi-line inputs
-                Err((_, EExpr::DefMissingFinalExpr(_), _))
-                | Err((_, EExpr::DefMissingFinalExpr2(_, _), _))
-                | Err((_, EExpr::Closure(EClosure::Body(_, _), _), _)) => {
-                    Ok(ValidationResult::Incomplete)
-                }
-                Err((_, _, state)) => {
-                    // It wasn't a valid top-level decl, so continue parsing it as an expr.
-                    match roc_parse::expr::parse_loc_expr(0, &arena, state) {
-                        // Special case some syntax errors to allow for multi-line inputs
-                        Err((_, EExpr::DefMissingFinalExpr(_), _))
-                        | Err((_, EExpr::DefMissingFinalExpr2(_, _), _))
-                        | Err((_, EExpr::Closure(EClosure::Body(_, _), _), _)) => {
-                            Ok(ValidationResult::Incomplete)
-                        }
-                        _ => Ok(ValidationResult::Valid(None)),
-                    }
-                }
-                Ok(_) => Ok(ValidationResult::Valid(None)),
-            };
 
-            // This is necessary to extend the lifetime of `arena`; without it,
+pub fn validate(input: &str) -> rustyline::Result<ValidationResult> {
-            // we get a borrow checker error!
+    if input.is_empty() {
-            answer
+        Ok(ValidationResult::Incomplete)
+    } else {
+        let arena = Bump::new();
+
+        match parse_src(&arena, input) {
+            // Standalone annotations are default incomplete, because we can't know
+            // whether they're about to annotate a body on the next line
+            // (or if not, meaning they stay standalone) until you press Enter again!
+            ParseOutcome::ValueDef(ValueDef::Annotation(_, _)) | ParseOutcome::Incomplete => {
+                Ok(ValidationResult::Incomplete)
+            }
+            ParseOutcome::ValueDef(_) | ParseOutcome::TypeDef(_) | ParseOutcome::Expr(_) => {
+                Ok(ValidationResult::Valid(None))
+            }
         }
     }
 }
@@ -289,66 +323,3 @@ fn format_output(output: ReplOutput) -> String {
         ReplOutput::Problems(lines) => format!("\n{}\n", lines.join("\n\n")),
     }
 }
-
-fn gen_and_eval_llvm<'a>(
-    src: &str,
-    target: Triple,
-    opt_level: OptLevel,
-    val_name: String,
-) -> Result<ReplOutput, SyntaxError<'a>> {
-    let arena = Bump::new();
-    let target_info = TargetInfo::from(&target);
-
-    let mut loaded = match compile_to_mono(&arena, src, target_info, DEFAULT_PALETTE) {
-        Ok(x) => x,
-        Err(prob_strings) => {
-            return Ok(ReplOutput::Problems(prob_strings));
-        }
-    };
-
-    debug_assert_eq!(loaded.exposed_to_host.values.len(), 1);
-    let (main_fn_symbol, main_fn_var) = loaded.exposed_to_host.values.iter().next().unwrap();
-    let main_fn_symbol = *main_fn_symbol;
-    let main_fn_var = *main_fn_var;
-
-    // pretty-print the expr type string for later.
-    let expr_type_str = name_and_print_var(
-        main_fn_var,
-        &mut loaded.subs,
-        loaded.module_id,
-        &loaded.interns,
-        DebugPrint::NOTHING,
-    );
-
-    let (_, main_fn_layout) = match loaded.procedures.keys().find(|(s, _)| *s == main_fn_symbol) {
-        Some(layout) => *layout,
-        None => {
-            return Ok(ReplOutput::NoProblems {
-                expr: "<function>".to_string(),
-                expr_type: expr_type_str,
-                val_name,
-            });
-        }
-    };
-
-    let interns = loaded.interns.clone();
-
-    let (lib, main_fn_name, subs, layout_interner) =
-        mono_module_to_dylib(&arena, target, loaded, opt_level).expect("we produce a valid Dylib");
-
-    let mut app = CliApp { lib };
-
-    let res_answer = jit_to_ast(
-        &arena,
-        &mut app,
-        main_fn_name,
-        main_fn_layout,
-        main_fn_var,
-        &subs,
-        &interns,
-        layout_interner.into_global().fork(),
-        target_info,
-    );
-
-    Ok(format_answer(&arena, res_answer, expr_type_str, val_name))
-}

crates/repl_test/Cargo.toml

@@ -15,6 +15,7 @@ lazy_static = "1.4.0"
 indoc = "1.0.7"
 strip-ansi-escapes = "0.1.1"
 wasmer-wasi = "2.2.1"
+rustyline = {git = "https://github.com/roc-lang/rustyline", rev = "e74333c"}
 
 roc_repl_cli = {path = "../repl_cli"}
 roc_test_utils = {path = "../test_utils"}

crates/repl_test/src/cli.rs

@@ -3,7 +3,8 @@ use std::io::Write;
 use std::path::PathBuf;
 use std::process::{Command, ExitStatus, Stdio};
 
-use roc_repl_cli::{TIPS, WELCOME_MESSAGE};
+use roc_repl_cli::repl_state::TIPS;
+use roc_repl_cli::WELCOME_MESSAGE;
 use roc_test_utils::assert_multiline_str_eq;
 
 const ERROR_MESSAGE_START: char = '─';

crates/repl_test/src/lib.rs

@@ -5,6 +5,9 @@ extern crate lazy_static;
 #[cfg(test)]
 mod tests;
 
+#[cfg(test)]
+mod state;
+
 #[cfg(all(test, not(feature = "wasm")))]
 mod cli;
 

crates/repl_wasm/src/repl.rs

@@ -270,6 +270,8 @@ pub async fn entrypoint_from_js(src: String) -> Result<String, String> {
         target_info,
     );
 
+    let val_name = String::new(); // TODO
+
     // Transform the Expr to a string
     // `Result::Err` becomes a JS exception that will be caught and displayed
     match format_answer(arena, res_answer, expr_type_str, val_name) {