From 448140d2232a6f9045b278c3392dc517e4e63c12 Mon Sep 17 00:00:00 2001
From: Brian Carroll <brian.carroll.ireland@gmail.com>
Date: Wed, 23 Mar 2022 22:25:52 +0000
Subject: [PATCH] wasm: refactor to prepare for HigherOrder calls

---
 compiler/gen_wasm/src/backend.rs   |  8 ++++-
 compiler/gen_wasm/src/lib.rs       |  2 +-
 compiler/gen_wasm/src/low_level.rs | 48 +++++++++++++++++++++++++-----
 compiler/module/src/low_level.rs   |  2 +-
 4 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/compiler/gen_wasm/src/backend.rs b/compiler/gen_wasm/src/backend.rs
index 66aeadb673..d7337ab51b 100644
--- a/compiler/gen_wasm/src/backend.rs
+++ b/compiler/gen_wasm/src/backend.rs
@@ -799,11 +799,17 @@ impl<'a> WasmBackend<'a> {
                     ret_storage,
                 )
             }
+
             CallType::LowLevel { op: lowlevel, .. } => {
                 self.expr_call_low_level(*lowlevel, arguments, ret_sym, ret_layout, ret_storage)
             }
 
-            x => todo!("call type {:?}", x),
+            CallType::HigherOrder(higher_order_lowlevel) => {
+                // Note: Zig's calling convention bug will require a generated wrapper function!
+                todo!("higher order calls");
+            }
+
+            CallType::Foreign { .. } => todo!("CallType::Foreign"),
         }
     }
 
diff --git a/compiler/gen_wasm/src/lib.rs b/compiler/gen_wasm/src/lib.rs
index 57266be640..6d8eb1db4c 100644
--- a/compiler/gen_wasm/src/lib.rs
+++ b/compiler/gen_wasm/src/lib.rs
@@ -134,7 +134,7 @@ pub fn build_module_without_wrapper<'a>(
         println!("## procs");
         for proc in procs.iter() {
             println!("{}", proc.to_pretty(200));
-            // println!("{:#?}", proc);
+            // println!("{:?}", proc);
         }
     }
 
diff --git a/compiler/gen_wasm/src/low_level.rs b/compiler/gen_wasm/src/low_level.rs
index 86eb023cd8..90412ce3b3 100644
--- a/compiler/gen_wasm/src/low_level.rs
+++ b/compiler/gen_wasm/src/low_level.rs
@@ -1,9 +1,11 @@
 use bumpalo::collections::Vec;
 use roc_builtins::bitcode::{self, FloatWidth, IntWidth};
 use roc_error_macros::internal_error;
-use roc_module::low_level::{LowLevel, LowLevel::*};
+use roc_module::low_level::LowLevel;
 use roc_module::symbol::Symbol;
+use roc_mono::ir::HigherOrderLowLevel;
 use roc_mono::layout::{Builtin, Layout, UnionLayout};
+use roc_mono::low_level::HigherOrder;
 
 use crate::backend::WasmBackend;
 use crate::layout::CallConv;
@@ -174,6 +176,7 @@ impl<'a> LowLevelCall<'a> {
 
     ///  Main entrypoint from WasmBackend
     pub fn generate(&self, backend: &mut WasmBackend<'a>) {
+        use LowLevel::*;
         use CodeGenNumType::*;
 
         let panic_ret_type = || {
@@ -260,14 +263,21 @@ impl<'a> LowLevelCall<'a> {
                 _ => internal_error!("invalid storage for List"),
             },
 
+            ListMap | ListMap2 | ListMap3 | ListMap4 | ListMapWithIndex | ListKeepIf | ListWalk
+            | ListWalkUntil | ListWalkBackwards | ListKeepOks | ListKeepErrs | ListSortWith
+            | ListAny | ListAll | ListFindUnsafe | DictWalk => {
+                internal_error!("HigherOrder lowlevels should not be handled here")
+            }
+
             ListGetUnsafe | ListReplaceUnsafe | ListSingle | ListRepeat | ListReverse
             | ListConcat | ListContains | ListAppend | ListPrepend | ListJoin | ListRange
-            | ListMap | ListMap2 | ListMap3 | ListMap4 | ListMapWithIndex | ListKeepIf
-            | ListWalk | ListWalkUntil | ListWalkBackwards | ListKeepOks | ListKeepErrs
-            | ListSortWith | ListSublist | ListDropAt | ListSwap | ListAny | ListAll
-            | ListFindUnsafe | DictSize | DictEmpty | DictInsert | DictRemove | DictContains
-            | DictGetUnsafe | DictKeys | DictValues | DictUnion | DictIntersection
-            | DictDifference | DictWalk | SetFromList => {
+            | ListSublist | ListDropAt | ListSwap => {
+                todo!("{:?}", self.lowlevel);
+            }
+
+            DictSize | DictEmpty | DictInsert | DictRemove | DictContains | DictGetUnsafe
+            | DictKeys | DictValues | DictUnion | DictIntersection | DictDifference
+            | SetFromList => {
                 todo!("{:?}", self.lowlevel);
             }
 
@@ -705,7 +715,7 @@ impl<'a> LowLevelCall<'a> {
             "Cannot do `==` comparison on different types"
         );
 
-        let invert_result = matches!(self.lowlevel, NotEq);
+        let invert_result = matches!(self.lowlevel, LowLevel::NotEq);
 
         match arg_layout {
             Layout::Builtin(
@@ -921,3 +931,25 @@ fn num_is_finite(backend: &mut WasmBackend<'_>, argument: Symbol) {
         }
     }
 }
+
+fn gen_higher_order(higher_order: HigherOrder) {
+    use HigherOrder::*;
+    match higher_order {
+        ListMap { .. }
+        | ListMap2 { .. }
+        | ListMap3 { .. }
+        | ListMap4 { .. }
+        | ListMapWithIndex { .. }
+        | ListKeepIf { .. }
+        | ListWalk { .. }
+        | ListWalkUntil { .. }
+        | ListWalkBackwards { .. }
+        | ListKeepOks { .. }
+        | ListKeepErrs { .. }
+        | ListSortWith { .. }
+        | ListAny { .. }
+        | ListAll { .. }
+        | ListFindUnsafe { .. }
+        | DictWalk { .. } => todo!("{:?}", higher_order),
+    }
+}
diff --git a/compiler/module/src/low_level.rs b/compiler/module/src/low_level.rs
index 98feb49ea8..1271816043 100644
--- a/compiler/module/src/low_level.rs
+++ b/compiler/module/src/low_level.rs
@@ -240,7 +240,7 @@ impl LowLevelWrapperType {
             Symbol::LIST_PREPEND => CanBeReplacedBy(ListPrepend),
             Symbol::LIST_JOIN => CanBeReplacedBy(ListJoin),
             Symbol::LIST_RANGE => CanBeReplacedBy(ListRange),
-            Symbol::LIST_MAP => CanBeReplacedBy(ListMap),
+            Symbol::LIST_MAP => WrapperIsRequired,
             Symbol::LIST_MAP2 => CanBeReplacedBy(ListMap2),
             Symbol::LIST_MAP3 => CanBeReplacedBy(ListMap3),
             Symbol::LIST_MAP4 => CanBeReplacedBy(ListMap4),