commit some crimes

compiler/load/src/file.rs

@@ -2239,17 +2239,21 @@ fn fabricate_effects_module<'a>(
 
         module_ids.get_or_insert(&declared_name)
     };
+    let mut scope = roc_can::scope::Scope::new(module_id, &mut var_store);
 
     let effect_symbol = {
         let mut ident_ids_by_module = (*ident_ids_by_module).lock();
 
         let ident_ids: &mut IdentIds = ident_ids_by_module.get_mut(&module_id).unwrap();
+        //let ident_id = ident_ids.get_or_insert(&declared_name);
+        //Symbol::new(module_id, ident_id)
 
-        let ident_id = ident_ids.get_or_insert(&declared_name);
+        let ident = declared_name.clone().into();
-        Symbol::new(module_id, ident_id)
+        scope
+            .introduce(ident, &(ident_ids.clone()), ident_ids, Region::zero())
+            .unwrap()
     };
 
-    let mut scope = roc_can::scope::Scope::new(module_id, &mut var_store);
     let mut aliases = MutMap::default();
     let alias = {
         let a_var = var_store.fresh();
@@ -2273,14 +2277,14 @@ fn fabricate_effects_module<'a>(
             actual,
         );
 
-        scope.lookup_alias(effect_symbol).clone()
+        scope.lookup_alias(effect_symbol).unwrap().clone()
     };
 
     aliases.insert(effect_symbol, alias);
 
     let mut declarations = Vec::new();
 
-    let exposed_symbols = {
+    let exposed_vars_by_symbol = {
         let module_ids = (*module_ids).lock();
         let mut ident_ids_by_module = (*ident_ids_by_module).lock();
 
@@ -2289,7 +2293,7 @@ fn fabricate_effects_module<'a>(
         let ident_id = ident_ids.get_or_insert(&declared_name);
         let effect_symbol = Symbol::new(module_id, ident_id);
 
-        let mut exposed = MutSet::default();
+        let mut exposed_vars_by_symbol = Vec::new();
 
         {
             use bumpalo::collections::Vec;
@@ -2316,8 +2320,6 @@ fn fabricate_effects_module<'a>(
                         let ident_id = ident_ids.get_or_insert(&as_inlinable_string);
                         let symbol = Symbol::new(module_id, ident_id);
 
-                        exposed.insert(symbol);
-
                         let annotation = roc_can::annotation::canonicalize_annotation(
                             &mut can_env,
                             &mut scope,
@@ -2335,6 +2337,8 @@ fn fabricate_effects_module<'a>(
                             annotation,
                         );
 
+                        exposed_vars_by_symbol.push((symbol, def.expr_var));
+
                         declarations.push(Declaration::Declare(def));
                     }
                     EffectsEntry::SpaceAfter(nested, _) | EffectsEntry::SpaceBefore(nested, _) => {
@@ -2344,19 +2348,19 @@ fn fabricate_effects_module<'a>(
             }
         }
 
-        exposed
+        exposed_vars_by_symbol
     };
 
     use roc_can::module::ModuleOutput;
     let module_output = ModuleOutput {
-        aliases: MutMap::default(),
+        aliases,
         rigid_variables: MutMap::default(),
         declarations,
         exposed_imports: MutMap::default(),
         lookups: Vec::new(),
         problems: Vec::new(),
         ident_ids: IdentIds::default(),
-        exposed_vars_by_symbol: Vec::new(),
+        exposed_vars_by_symbol,
         references: MutSet::default(),
     };
 

compiler/mono/src/ir.rs

@@ -3,7 +3,7 @@ use crate::exhaustive::{Ctor, Guard, RenderAs, TagId};
 use crate::layout::{Builtin, ClosureLayout, Layout, LayoutCache, LayoutProblem};
 use bumpalo::collections::Vec;
 use bumpalo::Bump;
-use roc_collections::all::{default_hasher, MutMap, MutSet};
+use roc_collections::all::{default_hasher, MutMap, MutSet, SendMap};
 use roc_module::ident::{Ident, Lowercase, TagName};
 use roc_module::low_level::LowLevel;
 use roc_module::symbol::{IdentIds, ModuleId, Symbol};
@@ -1427,6 +1427,62 @@ pub fn specialize_all<'a>(
     procs
 }
 
+fn hacky_hacky_hack_hack<'a>(
+    env: &mut Env<'a, '_>,
+    fn_var: Variable,
+    body: roc_can::expr::Expr,
+    arg_symbols: &[Symbol],
+) -> roc_can::expr::Expr {
+    match env.subs.get(fn_var).content {
+        Content::Structure(FlatType::Func(args, closure_var, ret_var)) => {
+            let temp = env.unique_symbol();
+
+            let pattern = roc_can::pattern::Pattern::Identifier(temp);
+            let mut pattern_vars = SendMap::default();
+            pattern_vars.insert(temp, fn_var);
+            let def = roc_can::def::Def {
+                loc_pattern: Located::at_zero(pattern),
+                loc_expr: Located::at_zero(body),
+                expr_var: fn_var,
+                pattern_vars,
+                annotation: None,
+            };
+
+            let mut arguments: std::vec::Vec<(Variable, Located<roc_can::expr::Expr>)> =
+                std::vec::Vec::new();
+
+            for (symbol, var) in arg_symbols.iter().zip(args.iter()) {
+                arguments.push((*var, Located::at_zero(roc_can::expr::Expr::Var(*symbol))));
+            }
+
+            use roc_module::operator::CalledVia;
+            // Box<(Variable, Located<Expr>, Variable, Variable)>,
+            let boxed = (
+                fn_var,
+                Located::at_zero(roc_can::expr::Expr::Var(temp)),
+                closure_var,
+                ret_var,
+            );
+            let call_temp = roc_can::expr::Expr::Call(Box::new(boxed), arguments, CalledVia::Space);
+
+            roc_can::expr::Expr::LetNonRec(
+                Box::new(def),
+                Box::new(Located::at_zero(call_temp)),
+                ret_var,
+            )
+        }
+        Content::Alias(_, _, actual) => hacky_hacky_hack_hack(env, actual, body, arg_symbols),
+        Content::Structure(FlatType::TagUnion(tags, _)) => {
+            let mut it = tags.iter();
+            let (_, args) = it.next().unwrap();
+            let mut it = args.iter();
+            let var = it.next().unwrap();
+            hacky_hacky_hack_hack(env, *var, body, arg_symbols)
+        }
+        other => unreachable!("{:?}", other),
+    }
+}
+
 fn specialize_external<'a>(
     env: &mut Env<'a, '_>,
     procs: &mut Procs<'a>,
@@ -1453,8 +1509,6 @@ fn specialize_external<'a>(
     let is_valid = matches!(unified, roc_unify::unify::Unified::Success(_));
     debug_assert!(is_valid);
 
-    let mut specialized_body = from_can(env, fn_var, body, procs, layout_cache);
-
     // if this is a closure, add the closure record argument
     let pattern_symbols = if let CapturedSymbols::Captured(_) = captured_symbols {
         let mut temp = Vec::from_iter_in(pattern_symbols.iter().copied(), env.arena);
@@ -1464,9 +1518,73 @@ fn specialize_external<'a>(
         pattern_symbols
     };
 
-    let (proc_args, opt_closure_layout, ret_layout) =
+    let spec_proc =
         build_specialized_proc_from_var(env, layout_cache, proc_name, pattern_symbols, fn_var)?;
 
+    match spec_proc {
+        SpecializedLayout::EmptyClosure(arg_layouts, ret_layout) => {
+            let mut arg_symbols = Vec::new_in(env.arena);
+            for _ in arg_layouts.iter() {
+                arg_symbols.push(env.unique_symbol());
+            }
+
+            let new_body = hacky_hacky_hack_hack(env, fn_var, body, &arg_symbols);
+
+            let specialized_body = from_can(env, fn_var, new_body, procs, layout_cache);
+            // determine the layout of aliases/rigids exposed to the host
+            let host_exposed_layouts = if host_exposed_variables.is_empty() {
+                HostExposedLayouts::NotHostExposed
+            } else {
+                let mut aliases = MutMap::default();
+
+                for (symbol, variable) in host_exposed_variables {
+                    let layout = layout_cache
+                        .from_var(env.arena, *variable, env.subs)
+                        .unwrap();
+                    aliases.insert(*symbol, layout);
+                }
+
+                HostExposedLayouts::HostExposed {
+                    rigids: MutMap::default(),
+                    aliases,
+                }
+            };
+
+            // reset subs, so we don't get type errors when specializing for a different signature
+            layout_cache.rollback_to(cache_snapshot);
+            env.subs.rollback_to(snapshot);
+
+            let recursivity = if is_self_recursive {
+                SelfRecursive::SelfRecursive(JoinPointId(env.unique_symbol()))
+            } else {
+                SelfRecursive::NotSelfRecursive
+            };
+
+            let closure_data_layout = None;
+
+            let proc_args = Vec::from_iter_in(
+                arg_symbols
+                    .iter()
+                    .zip(arg_layouts.into_iter())
+                    .map(|(s, l)| (l.clone(), *s)),
+                env.arena,
+            );
+            let proc_args = proc_args.into_bump_slice();
+
+            let proc = Proc {
+                name: proc_name,
+                args: proc_args,
+                body: specialized_body,
+                closure_data_layout,
+                ret_layout,
+                is_self_recursive: recursivity,
+                host_exposed_layouts,
+            };
+
+            Ok(proc)
+        }
+        SpecializedLayout::Normal(proc_args, opt_closure_layout, ret_layout) => {
+            let mut specialized_body = from_can(env, fn_var, body, procs, layout_cache);
             // unpack the closure symbols, if any
             if let CapturedSymbols::Captured(captured) = captured_symbols {
                 let mut layouts = Vec::with_capacity_in(captured.len(), env.arena);
@@ -1494,7 +1612,8 @@ fn specialize_external<'a>(
                     // layout is cached anyway, re-using the one found above leads to
                     // issues (combining by-ref and by-move in pattern match
                     let layout = layout_cache.from_var(env.arena, *variable, env.subs)?;
-            specialized_body = Stmt::Let(*symbol, expr, layout, env.arena.alloc(specialized_body));
+                    specialized_body =
+                        Stmt::Let(*symbol, expr, layout, env.arena.alloc(specialized_body));
                 }
             }
 
@@ -1543,13 +1662,18 @@ fn specialize_external<'a>(
             };
 
             Ok(proc)
+        }
+    }
 }
 
-type SpecializedLayout<'a> = (
+enum SpecializedLayout<'a> {
+    Normal(
         &'a [(Layout<'a>, Symbol)],
         Option<ClosureLayout<'a>>,
         Layout<'a>,
-);
+    ),
+    EmptyClosure(&'a [Layout<'a>], Layout<'a>),
+}
 
 #[allow(clippy::type_complexity)]
 fn build_specialized_proc_from_var<'a>(
@@ -1669,14 +1793,17 @@ fn build_specialized_proc_adapter<'a>(
 #[allow(clippy::type_complexity)]
 fn build_specialized_proc<'a>(
     arena: &'a Bump,
-    _proc_name: Symbol,
+    proc_name: Symbol,
     pattern_symbols: &[Symbol],
-    pattern_layouts: Vec<Layout<'a>>,
+    pattern_layouts: Vec<'a, Layout<'a>>,
     opt_closure_layout: Option<ClosureLayout<'a>>,
     ret_layout: Layout<'a>,
 ) -> Result<SpecializedLayout<'a>, LayoutProblem> {
+    use SpecializedLayout::*;
+
     let mut proc_args = Vec::with_capacity_in(pattern_layouts.len(), arena);
 
+    let pattern_layouts_slice = pattern_layouts.clone().into_bump_slice();
     let pattern_layouts_len = pattern_layouts.len();
 
     for (arg_layout, arg_name) in pattern_layouts.into_iter().zip(pattern_symbols.iter()) {
@@ -1714,7 +1841,7 @@ fn build_specialized_proc<'a>(
 
             let proc_args = proc_args.into_bump_slice();
 
-            Ok((proc_args, Some(layout), ret_layout))
+            Ok(Normal(proc_args, Some(layout), ret_layout))
         }
         Some(layout) => {
             // else if there is a closure layout, we're building the `f_closure` value
@@ -1729,7 +1856,7 @@ fn build_specialized_proc<'a>(
             let closure_layout =
                 Layout::Struct(arena.alloc([function_ptr_layout, closure_data_layout]));
 
-            Ok((&[], None, closure_layout))
+            Ok(Normal(&[], None, closure_layout))
         }
         None => {
             // else we're making a normal function, no closure problems to worry about
@@ -1738,16 +1865,15 @@ fn build_specialized_proc<'a>(
             // make sure there is not arg_closure argument without a closure layout
             debug_assert!(pattern_symbols.last() != Some(&Symbol::ARG_CLOSURE));
 
-            // since this is not a closure, the number of arguments should match between symbols
+            match pattern_layouts_len - pattern_symbols.len() {
-            // and layout
+                0 => {
-            debug_assert_eq!(
-                pattern_layouts_len,
-                pattern_symbols.len(),
-                "Tried to zip two vecs with different lengths!"
-            );
                     let proc_args = proc_args.into_bump_slice();
 
-            Ok((proc_args, None, ret_layout))
+                    Ok(Normal(proc_args, None, ret_layout))
+                }
+                1 => Ok(EmptyClosure(pattern_layouts_slice, ret_layout)),
+                _ => panic!(),
+            }
         }
     }
 }

compiler/mono/src/layout.rs

@@ -109,10 +109,8 @@ impl<'a> ClosureLayout<'a> {
 
                 use UnionVariant::*;
                 match variant {
-                    Never | Unit => {
+                    Never => Ok(None),
-                        // a max closure size of 0 means this is a standard top-level function
+                    Unit => Ok(None),
-                        Ok(None)
-                    }
                     BoolUnion { .. } => {
                         let closure_layout = ClosureLayout::from_bool(arena);