Allow let to bind capitalized unapplied identifiers

Author: LPTK

hkmc2/shared/src/main/scala/hkmc2/semantics/Elaborator.scala

@@ -833,7 +833,8 @@ extends Importer:
         newCtx.givenIn:
           go(sts, funs, Nil, newAcc)
 
-      case (hd @ LetLike(`let`, Apps(id: Ident, tups), rhso, N)) :: sts if id.name.headOption.exists(_.isLower) =>
+      case (hd @ LetLike(`let`, Apps(id: Ident, tups), rhso, N)) :: sts
+        if tups.isEmpty || id.name.headOption.exists(_.isLower) =>
         val sym =
           fieldOrVarSym(LetBind, id)
         log(s"Processing `let` statement $id (${sym}) ${ctx.outer}")

hkmc2/shared/src/test/mlscript/codegen/ImportJSClass.mls

@@ -11,13 +11,10 @@ MyClass
 new MyClass("Bob")
 //│ = [object Object]
 
-:todo
 let C = MyClass
-//│ ╔══[ERROR] Unsupported let binding shape
-//│ ║  l.15: 	let C = MyClass
-//│ ╙──      	    ^^^^^^^^^^^
+//│ C = class MyClass {  constructor(name) {    this.name = name;  }  greet() {    console.log(`Hello from ${this.name}!`);  }}
 
-let c = MyClass
+let c = C
 //│ c = class MyClass {  constructor(name) {    this.name = name;  }  greet() {    console.log(`Hello from ${this.name}!`);  }}
 
 :todo
@@ -33,7 +30,7 @@ fun foo() =
   import "../../js/MyClass.mjs"
   ()
 //│ ╔══[COMPILATION ERROR] Imports must be at the top level
-//│ ║  l.33: 	  import "../../js/MyClass.mjs"
+//│ ║  l.30: 	  import "../../js/MyClass.mjs"
 //│ ╙──      	         ^^^^^^^^^^^^^^^^^^^^^^
 
 

hkmc2/shared/src/test/mlscript/codegen/LetPatterns.mls

@@ -10,21 +10,33 @@ let Some(x) = Some(42)
 //│ ╙──     	    ^^^^^^^^^^^^^^^^^^
 
 
+object None
+
+let N = None
+//│ N = None
+
+:todo
+let (None) = N
+//│ ╔══[ERROR] Unsupported let binding shape
+//│ ║  l.19: 	let (None) = N
+//│ ╙──      	    ^^^^^^^^^^
+
+
 class Foo(a)
 
 :todo
 let Foo(x) = Foo(1) in log(x)
 //│ ╔══[ERROR] Unsupported let binding shape
-//│ ║  l.16: 	let Foo(x) = Foo(1) in log(x)
+//│ ║  l.28: 	let Foo(x) = Foo(1) in log(x)
 //│ ╙──      	    ^^^^^^^^^^^^^^^
 //│ ╔══[ERROR] Name not found: x
-//│ ║  l.16: 	let Foo(x) = Foo(1) in log(x)
+//│ ║  l.28: 	let Foo(x) = Foo(1) in log(x)
 //│ ╙──      	                           ^
 
 :todo
 let Foo(x) and x > 0 = Foo(1) in log("ok")
 //│ ╔══[ERROR] Unsupported let binding shape
-//│ ║  l.25: 	let Foo(x) and x > 0 = Foo(1) in log("ok")
+//│ ║  l.37: 	let Foo(x) and x > 0 = Foo(1) in log("ok")
 //│ ╙──      	    ^^^^^^^^^^^^^^^^^^^^^^^^^