Improve handling of frame slots (#1634)

This makes various improvements to the handling of frame slot vars, and includes some bug fixes introduced by https://github.com/apple/pkl/pull/1622 * Refactor SymbolTable to track for-generator and parameter slots in each scope * Execute let expressions in their own root node in some places * Unify how frame slots are managed; they are all represented as `FrameSlotVariable`, created in `AstBuilder`, and passed into `SymbolTable`. * Fix how let expressions are executed in custom this scopes (introduce a new root node when needed)
2026-06-25 14:56:19 +02:00 · 2026-06-10 20:02:42 -07:00
parent 27fe06c796
commit 84d2c32d10
30 changed files with 1000 additions and 278 deletions
@@ -0,0 +1,30 @@
+// let expr inside custom this scopes
+typealias Foo = String(let (x = this) this == x)
+
+typealias Foo2 = String(let (x = "foo") this.startsWith(x), let (y = "o") this.endsWith(y))
+
+typealias Foo3 = String(let (x = "foo") this.startsWith(x))(let (y = "o") this.endsWith(y))
+
+res1: Foo = "foo"
+
+res2: Foo2 = "foo"
+
+res3: Foo3 = "foo"
+
+hidden bar {
+  new {
+    name = "fooey"
+  }
+}
+
+res4 = (bar) {
+  [[let (x = "foo") this.name.startsWith(x)]] {
+    name = "bob"
+  }
+}
+
+res5 = (bar) {
+  [[let (x = this) x.name.startsWith("foo")]] {
+    name = "bob"
+  }
+}
@@ -0,0 +1,53 @@
+res =
+  let (
+    x = new Listing {
+      for (elem in List(1, 2)) {
+        elem + 5
+      }
+    }
+  )
+    x
+
+res2 =
+  let (qux = 1)
+  let (
+    x = new Listing {
+      for (num in List(1, 2)) {
+        qux + num
+      }
+    }
+  )
+    x
+
+res3 =
+  let (qux = 1)
+  let (
+    x = new Listing {
+      for (num in List(1, 2)) {
+        qux + num
+      }
+    }
+  )
+  let (y = 5)
+  let (
+    z = new Listing {
+      for (nummm in List(1, 2)) {
+        when (qux + y == nummm) {
+          nummm + y
+        }
+      }
+    }
+  )
+    new { ...x; ...z }
+
+res4 = 
+  let (m: Mapping<String, String> = new Mapping {
+    ["foo"] = "bar"
+  })
+    new Mapping {
+      for (k, _ in Map("foo", "bar")) {
+        [k] {
+          m[k]
+        }
+      }
+    }
@@ -0,0 +1,11 @@
+prop = "qux"
+
+res =
+  new Mapping {
+    default {
+      when (module.prop == "qux") {
+        myProp = "qux"
+      }
+    }
+    ["bar"] {}
+  }
@@ -480,3 +480,16 @@ whenWithElse = new Dynamic {
    }
  }
 }
+
+local func = (it) -> new Listing {
+  for (elem1 in List(1, 2)) {
+    it
+    new Listing {
+      for (elem2 in List(1, 2)) {
+        elem1 + elem2
+      }
+    }
+  }
+}
+
+nestedForsWithinLambda = func.apply("hi")
@@ -475,3 +475,42 @@ withinLetExpr =
        [k] = v
      }
    }
+
+// object bodies that are children of for-generators inherit the frame descriptor of the parent object
+nestedObjectInsideFor {
+  for (idx, qux in List(1, 2)) {
+    [idx] {
+      for (baz in List(1, 2)) {
+        when (baz == qux) {
+          baz
+        }
+      }
+    }
+  }
+}
+
+// object bodies inherit the frame descriptor of the parent object
+doublyNestedObjectInsideFor {
+  for (idx, qux in List(1, 2)) {
+    [idx] {
+      new Listing {
+        for (baz in List(1, 2)) {
+          when (baz == qux) {
+            baz
+          }
+        }
+      }
+    }
+  }
+}
+
+insideObjectBodyWithParam: Mapping<String, Dynamic> = new {
+  default { key ->
+    for (key, value in Map("foo", List(new Dynamic { bar = 1 }))) {
+      [key] {
+        ...value
+      }
+    }
+  }
+  ["res"] {}
+}
@@ -1,7 +1,7 @@
 examples {
  local a = List("1", "2", "3", "4")
  local b = List("a", "b", "c", "d")
-  
+
  ["shadow key variable"] {
    new {
      for (key, outerValue in a) {
@@ -0,0 +1,5 @@
+res {
+  for (prefix in List("foo")) {
+    "foobar" as String(let (y = this) y.startsWith(prefix))
+  }
+}
@@ -43,7 +43,8 @@ res5 = new {

 // nested predicate
 res6 = (people) {
-  [[(people) { [[name == "Barn Owl"]] { age = 99 } }.toList().find((it) -> it.age == 99).name == name]] {
+  [[(people) { [[name == "Barn Owl"]] { age = 99 } }.toList().find((it) -> it.age == 99).name
+    == name]] {
    age = 55
  }
 }
@@ -86,3 +87,28 @@ res12 = (people) {
    [[name == "Pigeon"]] { age = 122 }
  }
 }
+
+res13 = (people) {
+  [[(() -> this.name == "Pigeon").apply()]] {
+    age = 99
+  }
+}
+
+res14 = (people) {
+  for (foo in List(1, 2)) {
+    [[foo == 1]] {
+      age = foo
+    }
+  }
+}
+
+res15 =
+  (
+    (it) -> (people) {
+      for (foo in List(1, 2)) {
+        [[foo == 1]] {
+          age = foo
+        }
+      }
+    }
+  ).apply("hi")
@@ -0,0 +1,13 @@
+res1 = "foo"
+res2 = "foo"
+res3 = "foo"
+res4 {
+  new {
+    name = "bob"
+  }
+}
+res5 {
+  new {
+    name = "bob"
+  }
+}
@@ -0,0 +1,17 @@
+res {
+  6
+  7
+}
+res2 {
+  2
+  3
+}
+res3 {
+  2
+  3
+}
+res4 {
+  ["foo"] {
+    "bar"
+  }
+}
@@ -0,0 +1,6 @@
+prop = "qux"
+res {
+  ["bar"] {
+    myProp = "qux"
+  }
+}
@@ -335,3 +335,15 @@ whenWithElse {
  20
  40
 }
+nestedForsWithinLambda {
+  "hi"
+  new {
+    2
+    3
+  }
+  "hi"
+  new {
+    3
+    4
+  }
+}
@@ -323,3 +323,32 @@ withinLetExpr {
  ["a"] = 1
  ["b"] = 2
 }
+nestedObjectInsideFor {
+  [0] {
+    1
+  }
+  [1] {
+    2
+  }
+}
+doublyNestedObjectInsideFor {
+  [0] {
+    new {
+      1
+    }
+  }
+  [1] {
+    new {
+      2
+    }
+  }
+}
+insideObjectBodyWithParam {
+  ["res"] {
+    ["foo"] {
+      new {
+        bar = 1
+      }
+    }
+  }
+}
@@ -0,0 +1,3 @@
+res {
+  "foobar"
+}
@@ -153,3 +153,45 @@ res12 {
    age = 33
  }
 }
+res13 {
+  new {
+    name = "Pigeon"
+    age = 99
+  }
+  new {
+    name = "Barn Owl"
+    age = 21
+  }
+  new {
+    name = "Parrot"
+    age = 33
+  }
+}
+res14 {
+  new {
+    name = "Pigeon"
+    age = 1
+  }
+  new {
+    name = "Barn Owl"
+    age = 1
+  }
+  new {
+    name = "Parrot"
+    age = 1
+  }
+}
+res15 {
+  new {
+    name = "Pigeon"
+    age = 1
+  }
+  new {
+    name = "Barn Owl"
+    age = 1
+  }
+  new {
+    name = "Parrot"
+    age = 1
+  }
+}