Replace new with alloc and initialize

Author: Ary Borenszweig

bin/icr

@@ -17,7 +17,7 @@ def count_openings(string)
     when :IDENT
       case token.value
       when :begin, :class, :def, :if, :If, :unless, :Unless, :while
-        openings += 1 if last_token.nil? || last_token == :';' || last_token == :NEWLINE
+        openings += 1
       when :do
         openings += 1
       when :end, :End

lib/crystal/ast.rb

@@ -122,10 +122,6 @@ def accept(visitor)
       visitor.end_visit_class self
     end
 
-    def ==(other)
-      other.is_a?(Class) && other.name == name
-    end
-
     def to_s
       @name
     end
@@ -873,10 +869,10 @@ def returns?
     end
   end
 
-  class NewClass < Expression
+  class Alloc < Expression
     def accept(visitor)
-      visitor.visit_new_class self
-      visitor.end_visit_new_class self
+      visitor.visit_alloc self
+      visitor.end_visit_alloc self
     end
   end
 end

lib/crystal/builtin.rb

@@ -28,11 +28,13 @@ def define_builtin_classes
 
     def define_object_class
       @object_class = define_class Class.new("Object")
+      @object_class.define_method Def.new('initialize', [], nil)
     end
 
     def define_class_class
       @class_class = define_class Class.new("Class", @object_class)
-      @class_class.define_method Def.new('new', [], NewClass.new)
+      @class_class.define_method Def.new('new', [], nil)
+      @class_class.define_method Def.new('alloc', [], Alloc.new)
       @object_class.class_class = @class_class
     end
 

lib/crystal/codegen.rb

@@ -665,7 +665,7 @@ def codegen(mod)
     end
   end
 
-  class NewClass
+  class Alloc
     def codegen(mod)
       malloc = mod.builder.call mod.malloc, LLVM::Int(0)
       mod.builder.bit_cast malloc, resolved_type.llvm_type(mod)

lib/crystal/resolve.rb

@@ -206,9 +206,9 @@ def visit_call(node)
         method = node.obj.resolved_type.find_method(node.name)
 
         if method
-          #if method.obj == @scope.class_class && method.name == 'new'
-
-          #end
+          if method.is_a?(Def) && method.obj == @scope.class_class && method.name == 'new'
+            return replace_new_with_alloc_and_initialize node
+          end
         else
           # Special case: rewrite a != b as !(a == b)
           return rewrite_not_equals node if node.name == :'!='
@@ -298,6 +298,21 @@ def visit_call(node)
       false
     end
 
+    def replace_new_with_alloc_and_initialize(node)
+      @@temp_name_index ||= 0
+      @@temp_name_index += 1
+      temp_name = "*temp#{@@temp_name_index}"
+
+      exps = Expressions.new
+      exps.expressions << Assign.new(Ref.new(temp_name), Call.new(node.obj, "alloc"))
+      exps.expressions << Call.new(Ref.new(temp_name), "initialize", node.args)
+      exps.expressions << Ref.new(temp_name)
+      exps.accept self
+
+      node.parent.replace node, exps
+      return false
+    end
+
     def rewrite_not_equals(node)
       node.name = :'=='
       node.resolved_type = nil
@@ -446,7 +461,7 @@ def visit_static_array_get(node)
       false
     end
 
-    def visit_new_class(node)
+    def visit_alloc(node)
       node.resolved_type = @scope.def.args[0].resolved_type.real_class
       false
     end

lib/crystal/visitor.rb

@@ -42,7 +42,7 @@ class Visitor
       'new_static_array',
       'static_array_set',
       'static_array_get',
-      'new_class',
+      'alloc',
     ].each do |name|
       class_eval %Q(
         def visit_#{name}(node)

spec/eval_spec.rb

@@ -131,6 +131,7 @@ def self.it_evals_class(string, expected_value, options = {})
   it_evals "def Int.bar; 1; end; def StaticArray.foo; T; end; StaticArray(Int).foo.bar", 1.int
   it_evals "class Number; def foo; If self.class == Int; 1; Else; 2; End; end; end; 1.foo + 1.0.foo", 3.int
   it_evals "def Number.foo; If self == Int; 1; Else; 2; End; end; Int.foo + Float.foo", 3.int
+  it_evals "class Foo; def bar; 1; end; end; foo = Foo.alloc; foo.bar", 1.int
   it_evals "class Foo; def bar; 1; end; end; foo = Foo.new; foo.bar", 1.int
   it_evals "class Foo; def initialize(x); end; def bar; 1; end; end; foo = Foo.new(1); foo.bar", 1.int
 end