Object literals and class objects

examples/src/Factories.jetl

@@ -1,17 +1,16 @@
 class Foo(bar : Bar) {
+  class object {
+    private val cache = HashMap<Bar, Foo>()
 
-} static {
+// Factory method:
-  private val cache = HashMap<Bar, Foo>()
+    Foo() = Foo(null);
 
-  Foo() {
+// Factory method:
-    return Foo(null);
+    Foo(bar : Bar) = cache.cachedLookup(bar, this(bar))
   }
 
-  Foo(bar : Bar) {
+  fun doFoo() {
-    if (bar in cache.keys) return cache[bar]
+    // ...
-    val newFoo = this(bar) // calls the primary constructor
-    cahce[bar] = newFoo
-    return newFoo
   }
 }
 
@@ -24,3 +23,12 @@ val foo = Foo(Bar())
 class FooSub(S : String) : Foo() { // Delegates to Foo created as a result of the factory method Foo()
 
 }
+
+extension Map<K, V>.cachedLookup(key : K, lazy value : V) : V {
+  var v = this[key]
+  if (v == null) {
+    v = value
+    this[key] = value
+  }
+  return v
+}

grammar/src/class_members.grm

@@ -30,11 +30,15 @@ class Example(a : Foo, i : Int) : Bar(i), Some {
 // h5. Grammar
 
 memberDeclaration
+  : classObject
   : constructor
   : method
   : property
-  : class //TODO : static
+  : class
-//  : constant ???
+  ;
+
+classObject
+  : "class" objectLiteral
   ;
 
 constructor
@@ -51,7 +55,7 @@ super
   ;
 
 method
-  : methodModifier* "fun" SimpleName functionParameters (":" type)? functionBody?
+  : methodModifier* "fun" SimpleName typeParameters? functionParameters (":" type)? functionBody?
   ;
 
 functionParameters

grammar/src/expressions.grm

@@ -11,9 +11,8 @@ expression
   : expressionWithPrecedences
   : match
   : if
-  : "new" constructorInvocation
+  : "new" constructorInvocation // TODO: Do we need "new"?, see factory methods
-  : anonymousInnerClassInstantiation // TODO
+  : objectLiteral
-// TODO: list comprehension
   : jump
   ;
 
@@ -159,6 +158,23 @@ arrayAccess
   : "[" expression "]"
   ;
 
-anonymousInnerClassInstantiation
+objectLiteral
-  : "object" delegationSpecifier{","} classBody
+  : "object" delegationSpecifier{","} classBody?
   ;
+
+/* Factory methods:
+
+objectLiteral
+  : "object" delegationSpecifier{","} ("{" objectLiteralMember{","} "}")?
+  ;
+
+objectLiteralMember
+  : memberDeclaration
+  : factoryMethod
+  ;
+
+factoryMethod
+  : accessModifier? SimpleName typeParameters? functionParameters functionBody
+  ;
+
+*/