Map set syntax inits last map if key missing

base/Kind/Parser/lens.kind

@@ -29,15 +29,17 @@ Kind.Parser.lens(term: Kind.Term): Parser<Kind.Term>
   Parser {
     get dirs = Parser.many1!(Kind.Parser.lens.path)
     Parser.choice!([
-      Parser {
-        Kind.Parser.text("<-")
-        get xval = Kind.Parser.term
-        return Kind.Parser.lens.mutter(term, () xval, dirs)
-      }
+      // mut
       Parser {
         Kind.Parser.text("<~")
         get xfun = Kind.Parser.term
-        return Kind.Parser.lens.mutter(term, (x) Kind.Term.app(xfun, x), dirs)
+        return Kind.Parser.lens.mutter(term, (x) Kind.Term.app(xfun, x), dirs, false)
+      }
+      // set
+      Parser {
+        Kind.Parser.text("<-")
+        get xval = Kind.Parser.term
+        return Kind.Parser.lens.mutter(term, () xval, dirs, true)
       }
       Parser {
         return Kind.Parser.lens.getter(term, dirs)
@@ -50,33 +52,37 @@ Kind.Parser.lens.let(body: Unit -> Parser(Kind.Term)): Parser<Kind.Term>
     Kind.Parser.text("let ")
     get name = Kind.Parser.name1
     get dirs = Parser.many1!(Kind.Parser.lens.path)
-    get symb = Parser.option([Kind.Parser.text("<-"), Kind.Parser.text("<~")])
+    get symb = Parser.option([Kind.Parser.text("<~"), Kind.Parser.text("<-")])
     get expr = Kind.Parser.term
     Parser.maybe!(Kind.Parser.text(";"))
     get body = body(unit)
-    let expr = Kind.Parser.lens.mutter(Kind.Term.ref(name), case symb { zero: () expr, succ: (x) Kind.Term.app(expr,x) }, dirs)
+    let expr = case symb {
+      zero: Kind.Parser.lens.mutter(Kind.Term.ref(name), (x) Kind.Term.app(expr,x), dirs, false)
+      succ: Kind.Parser.lens.mutter(Kind.Term.ref(name), (x) expr, dirs, true)
+    }
     return Kind.Term.let(name, expr, (x) body)
   }
 
-Kind.Parser.lens.mutter(expr: Kind.Term, func: Kind.Term -> Kind.Term, dirs: List<Kind.Parser.lens.dir>): Kind.Term
+Kind.Parser.lens.mutter(expr: Kind.Term, func: Kind.Term -> Kind.Term, dirs: List<Kind.Parser.lens.dir>, is_set: Bool): Kind.Term
   case dirs {
     nil: func(expr)
     cons: case dirs.head {
       record:
-        //foo@x <- 7
-        Kind.Term.mut(expr, dirs.head.key, Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail)))
+        Kind.Term.mut(expr, dirs.head.key, Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail, is_set)))
       list:
         let term = Kind.Term.ref("List.mut")
         let term = Kind.Term.app(term, Kind.Term.hol(Bits.e))
         let term = Kind.Term.app(term, dirs.head.key)
-        let term = Kind.Term.app(term, Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail)))
+        let term = Kind.Term.app(term, Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail, is_set)))
         let term = Kind.Term.app(term, expr)
         term
       map:
-        let term = Kind.Term.ref("Map.mut")
+        let sets = List.is_empty!(dirs.tail) && is_set
+        let term = Kind.Term.ref(if sets then "Map.set" else "Map.mut")
         let term = Kind.Term.app(term, Kind.Term.hol(Bits.e))
         let term = Kind.Term.app(term, dirs.head.key)
-        let term = Kind.Term.app(term, Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail)))
+        let argf = if sets then func(Kind.Term.ref("?")) else Kind.Term.lam("x", (x) Kind.Parser.lens.mutter(x, func, dirs.tail, is_set))
+        let term = Kind.Term.app(term, argf)
         let term = Kind.Term.app(term, expr)
         term
     }

base/Test.kind

@@ -1,26 +1,4 @@
-type Object {
-  new(
-    name: String
-    data: Map<List<F64>>
-  )
-}
-
-Test: Maybe<F64>
-  let obj = Object.new("sample", {
-    "a": [1.0, 2.0, 3.0, 4.0, 5.0, 6.0]
-    "b": [7.0, 7.0, 7.0, 7.0, 7.0, 7.0]
-  })
-  let obj@data{"a"}[0] <~ F64.mul(2.0)
-  obj@data{"a"}[0]
-
-// ------------------------------------
-
-id<A: $Type>(x: A): A
-  x
-
-explicit: Nat
-  id<$Nat>(7)
-
-implicit: Nat
-  id(7)
-
+Test: _
+  let x = {"a": {"x":3}, "b": {"x":1}}
+  let x = x{"a"}{"y"} <- 10
+  List.show!(Nat.show, Map.values!(x{"a"} <> {}))

bin/js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "kind-lang",
-  "version": "1.0.105",
+  "version": "1.0.106",
   "description": "Kind-Lang in JavaScript",
   "main": "src/kind.js",
   "scripts": {