From 25457ffa19b60849a44e3113841cb6dbef3d15e6 Mon Sep 17 00:00:00 2001
From: Nat Quayle Nelson <natquaylenelson@gmail.com>
Date: Sun, 19 Jun 2022 21:33:20 +0000
Subject: [PATCH] don't try to type-guess on list expressions in case

---
 kiss/src/kiss/FieldForms.hx   |  3 ++-
 kiss/src/kiss/Helpers.hx      | 10 ++++++----
 kiss/src/kiss/SpecialForms.hx | 35 +++++++++++++++++++++++------------
 3 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/kiss/src/kiss/FieldForms.hx b/kiss/src/kiss/FieldForms.hx
index 2ed14717..bdbeb9db 100644
--- a/kiss/src/kiss/FieldForms.hx
+++ b/kiss/src/kiss/FieldForms.hx
@@ -102,7 +102,8 @@ class FieldForms {
             var access = fieldAccess(formName, name, args[0]);
 
             var type = Helpers.explicitType(args[0]);
-            k.typeHints.push({name: name, type: type});
+            if (type != null)
+                k.typeHints.push({name: name, type: type});
 
             ({
                 name: name,
diff --git a/kiss/src/kiss/Helpers.hx b/kiss/src/kiss/Helpers.hx
index dde00c67..f4952aff 100644
--- a/kiss/src/kiss/Helpers.hx
+++ b/kiss/src/kiss/Helpers.hx
@@ -173,7 +173,7 @@ class Helpers {
             };
         }
 
-        var args = switch (argList.def) {
+        var args:Array<FunctionArg> = switch (argList.def) {
             case ListExp(funcArgs):
                 funcArgs.map(makeFuncArg);
             case CallExp(_, _):
@@ -190,7 +190,8 @@ class Helpers {
         }];
 
         for (v in vars) {
-            k.typeHints.push(v);
+            if (v.type != null)
+                k.typeHints.push(v);
         }
 
         var expr = if (body.length == 0) {
@@ -206,7 +207,8 @@ class Helpers {
         }
 
         for (v in vars) {
-            k.typeHints.remove(v);
+            if (v.type != null)
+                k.typeHints.remove(v);
         }
 
         // To make function args immutable by default, we would use (let...) instead of (begin...)
@@ -217,7 +219,7 @@ class Helpers {
             ret: if (name != null) Helpers.explicitType(name) else null,
             args: args,
             expr: expr
-        }
+        };
     }
 
     // The name of this function is confusing--it actually makes a Haxe `case` expression, not a switch-case expression
diff --git a/kiss/src/kiss/SpecialForms.hx b/kiss/src/kiss/SpecialForms.hx
index ed22dae3..14794598 100644
--- a/kiss/src/kiss/SpecialForms.hx
+++ b/kiss/src/kiss/SpecialForms.hx
@@ -204,7 +204,8 @@ class SpecialForms {
             }
 
             for (v in varDefs) {
-                k.typeHints.push(v);
+                if (v.type != null)
+                    k.typeHints.push(v);
             }
 
             var block = EBlock([
@@ -213,7 +214,8 @@ class SpecialForms {
             ]).withMacroPosOf(wholeExp);
 
             for (v in varDefs) {
-                k.typeHints.remove(v);
+                if (v.type != null)
+                    k.typeHints.remove(v);
             }
 
             block;
@@ -322,16 +324,25 @@ class SpecialForms {
 
             // On C#, C++, and HashLink, value types (specifically Float and Int) cannot be null, so they cannot be compared with null.
             // Therefore a null case doesn't need to be added--and will cause a compile failure if it is.
-            var canCompareNull = if (Context.defined('cs') || Context.defined('cpp') || Context.defined('hl')) {
-                switch (exp.typeof(k.typeHints)) {
-                    case Success(TAbstract(ref, [])) if (["Int", "Float", "Bool"].indexOf(ref.get().name) != -1):
-                        false;
-                    case Failure(_):
-                        KissError.warnFromExp(args[0], "Can't detect whether expression can be null-checked");
-                        false;
-                    default: true;
-                }
-            } else true;
+            var canCompareNull = switch (args[0].def) {
+                // don't try to type [multiple caseArgs]! It will never return!
+                case ListExp(_):
+                    false;
+                default:
+                    if (Context.defined('cs') || Context.defined('cpp') || Context.defined('hl')) {
+                        var type = exp.typeof(k.typeHints);
+                        switch (type) {
+                            case null:
+                                false;
+                            case Success(TAbstract(ref, [])) if (["Int", "Float", "Bool"].indexOf(ref.get().name) != -1):
+                                false;
+                            case Failure(_):
+                                KissError.warnFromExp(args[0], "Can't detect whether expression can be null-checked");
+                                false;
+                            default: true;
+                        }
+                    } else true;
+            }
 
             var cases = args.slice(1);
             // case also override's haxe's switch() behavior by refusing to match null values against <var> patterns.