Adding Crystal samples to address https://github.com/github/github/issues/24802

samples/Crystal/const_spec.cr

@@ -0,0 +1,169 @@
+#!/usr/bin/env bin/crystal --run
+require "../../spec_helper"
+
+describe "Codegen: const" do
+  it "define a constant" do
+    run("A = 1; A").to_i.should eq(1)
+  end
+
+  it "support nested constant" do
+    run("class B; A = 1; end; B::A").to_i.should eq(1)
+  end
+
+  it "support constant inside a def" do
+    run("
+      class Foo
+        A = 1
+
+        def foo
+          A
+        end
+      end
+
+      Foo.new.foo
+    ").to_i.should eq(1)
+  end
+
+  it "finds nearest constant first" do
+    run("
+      A = 1
+
+      class Foo
+        A = 2.5_f32
+
+        def foo
+          A
+        end
+      end
+
+      Foo.new.foo
+    ").to_f32.should eq(2.5)
+  end
+
+  it "allows constants with same name" do
+    run("
+      A = 1
+
+      class Foo
+        A = 2.5_f32
+
+        def foo
+          A
+        end
+      end
+
+      A
+      Foo.new.foo
+    ").to_f32.should eq(2.5)
+  end
+
+  it "constants with expression" do
+    run("
+      A = 1 + 1
+      A
+    ").to_i.should eq(2)
+  end
+
+  it "finds global constant" do
+    run("
+      A = 1
+
+      class Foo
+        def foo
+          A
+        end
+      end
+
+      Foo.new.foo
+    ").to_i.should eq(1)
+  end
+
+  it "define a constant in lib" do
+    run("lib Foo; A = 1; end; Foo::A").to_i.should eq(1)
+  end
+
+  it "invokes block in const" do
+    run("require \"prelude\"; A = [\"1\"].map { |x| x.to_i }; A[0]").to_i.should eq(1)
+  end
+
+  it "declare constants in right order" do
+    run("A = 1 + 1; B = true ? A : 0; B").to_i.should eq(2)
+  end
+
+  it "uses correct types lookup" do
+    run("
+      module A
+        class B
+          def foo
+            1
+          end
+        end
+
+        C = B.new;
+      end
+
+      def foo
+        A::C.foo
+      end
+
+      foo
+      ").to_i.should eq(1)
+  end
+
+  it "codegens variable assignment in const" do
+    run("
+      class Foo
+        def initialize(@x)
+        end
+
+        def x
+          @x
+        end
+      end
+
+      A = begin
+            f = Foo.new(1)
+            f
+          end
+
+      def foo
+        A.x
+      end
+
+      foo
+      ").to_i.should eq(1)
+  end
+
+  it "declaring var" do
+    run("
+      BAR = begin
+        a = 1
+        while 1 == 2
+          b = 2
+        end
+        a
+      end
+      class Foo
+        def compile
+          BAR
+        end
+      end
+
+      Foo.new.compile
+      ").to_i.should eq(1)
+  end
+
+  it "initialize const that might raise an exception" do
+    run("
+      require \"prelude\"
+      CONST = (raise \"OH NO\" if 1 == 2)
+
+      def doit
+        CONST
+      rescue
+      end
+
+      doit.nil?
+    ").to_b.should be_true
+  end
+end

samples/Crystal/declare_var_spec.cr

@@ -0,0 +1,79 @@
+#!/usr/bin/env bin/crystal --run
+require "../../spec_helper"
+
+describe "Type inference: declare var" do
+  it "types declare var" do
+    assert_type("a :: Int32") { int32 }
+  end
+
+  it "types declare var and reads it" do
+    assert_type("a :: Int32; a") { int32 }
+  end
+
+  it "types declare var and changes its type" do
+    assert_type("a :: Int32; while 1 == 2; a = 'a'; end; a") { union_of(int32, char) }
+  end
+
+  it "declares instance var which appears in initialize" do
+    result = assert_type("
+      class Foo
+        @x :: Int32
+      end
+
+      Foo.new") { types["Foo"] }
+
+    mod = result.program
+
+    foo = mod.types["Foo"] as NonGenericClassType
+    foo.instance_vars["@x"].type.should eq(mod.int32)
+  end
+
+  it "declares instance var of generic class" do
+    result = assert_type("
+      class Foo(T)
+        @x :: T
+      end
+
+      Foo(Int32).new") do
+        foo = types["Foo"] as GenericClassType
+        foo_i32 = foo.instantiate([int32] of Type | ASTNode)
+        foo_i32.lookup_instance_var("@x").type.should eq(int32)
+        foo_i32
+    end
+  end
+
+  it "declares instance var of generic class after reopen" do
+    result = assert_type("
+      class Foo(T)
+      end
+
+      f = Foo(Int32).new
+
+      class Foo(T)
+        @x :: T
+      end
+
+      f") do
+        foo = types["Foo"] as GenericClassType
+        foo_i32 = foo.instantiate([int32] of Type | ASTNode)
+        foo_i32.lookup_instance_var("@x").type.should eq(int32)
+        foo_i32
+    end
+  end
+
+  it "declares an instance variable in initialize" do
+    assert_type("
+      class Foo
+        def initialize
+          @x :: Int32
+        end
+
+        def x
+          @x
+        end
+      end
+
+      Foo.new.x
+      ") { int32 }
+  end
+end

samples/Crystal/transformer.cr

@@ -0,0 +1,515 @@
+module Crystal
+  class ASTNode
+    def transform(transformer)
+      transformer.before_transform self
+      node = transformer.transform self
+      transformer.after_transform self
+      node
+    end
+  end
+
+  class Transformer
+    def before_transform(node)
+    end
+
+    def after_transform(node)
+    end
+
+    def transform(node : Expressions)
+      exps = [] of ASTNode
+      node.expressions.each do |exp|
+        new_exp = exp.transform(self)
+        if new_exp
+          if new_exp.is_a?(Expressions)
+            exps.concat new_exp.expressions
+          else
+            exps << new_exp
+          end
+        end
+      end
+
+      if exps.length == 1
+        exps[0]
+      else
+        node.expressions = exps
+        node
+      end
+    end
+
+    def transform(node : Call)
+      if node_obj = node.obj
+        node.obj = node_obj.transform(self)
+      end
+      transform_many node.args
+
+      if node_block = node.block
+        node.block = node_block.transform(self)
+      end
+
+      if node_block_arg = node.block_arg
+        node.block_arg = node_block_arg.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : And)
+      node.left = node.left.transform(self)
+      node.right = node.right.transform(self)
+      node
+    end
+
+    def transform(node : Or)
+      node.left = node.left.transform(self)
+      node.right = node.right.transform(self)
+      node
+    end
+
+    def transform(node : StringInterpolation)
+      transform_many node.expressions
+      node
+    end
+
+    def transform(node : ArrayLiteral)
+      transform_many node.elements
+
+      if node_of = node.of
+        node.of = node_of.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : HashLiteral)
+      transform_many node.keys
+      transform_many node.values
+
+      if of_key = node.of_key
+        node.of_key = of_key.transform(self)
+      end
+
+      if of_value = node.of_value
+        node.of_value = of_value.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : If)
+      node.cond = node.cond.transform(self)
+      node.then = node.then.transform(self)
+      node.else = node.else.transform(self)
+      node
+    end
+
+    def transform(node : Unless)
+      node.cond = node.cond.transform(self)
+      node.then = node.then.transform(self)
+      node.else = node.else.transform(self)
+      node
+    end
+
+    def transform(node : IfDef)
+      node.cond = node.cond.transform(self)
+      node.then = node.then.transform(self)
+      node.else = node.else.transform(self)
+      node
+    end
+
+    def transform(node : MultiAssign)
+      transform_many node.targets
+      transform_many node.values
+      node
+    end
+
+    def transform(node : SimpleOr)
+      node.left = node.left.transform(self)
+      node.right = node.right.transform(self)
+      node
+    end
+
+    def transform(node : Def)
+      transform_many node.args
+      node.body = node.body.transform(self)
+
+      if receiver = node.receiver
+        node.receiver = receiver.transform(self)
+      end
+
+      if block_arg = node.block_arg
+        node.block_arg = block_arg.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : Macro)
+      transform_many node.args
+      node.body = node.body.transform(self)
+
+      if receiver = node.receiver
+        node.receiver = receiver.transform(self)
+      end
+
+      if block_arg = node.block_arg
+        node.block_arg = block_arg.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : PointerOf)
+      node.exp = node.exp.transform(self)
+      node
+    end
+
+    def transform(node : SizeOf)
+      node.exp = node.exp.transform(self)
+      node
+    end
+
+    def transform(node : InstanceSizeOf)
+      node.exp = node.exp.transform(self)
+      node
+    end
+
+    def transform(node : IsA)
+      node.obj = node.obj.transform(self)
+      node.const = node.const.transform(self)
+      node
+    end
+
+    def transform(node : RespondsTo)
+      node.obj = node.obj.transform(self)
+      node
+    end
+
+    def transform(node : Case)
+      node.cond = node.cond.transform(self)
+      transform_many node.whens
+
+      if node_else = node.else
+        node.else = node_else.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : When)
+      transform_many node.conds
+      node.body = node.body.transform(self)
+      node
+    end
+
+    def transform(node : ImplicitObj)
+      node
+    end
+
+    def transform(node : ClassDef)
+      node.body = node.body.transform(self)
+
+      if superclass = node.superclass
+        node.superclass = superclass.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : ModuleDef)
+      node.body = node.body.transform(self)
+      node
+    end
+
+    def transform(node : While)
+      node.cond = node.cond.transform(self)
+      node.body = node.body.transform(self)
+      node
+    end
+
+    def transform(node : Generic)
+      node.name = node.name.transform(self)
+      transform_many node.type_vars
+      node
+    end
+
+    def transform(node : ExceptionHandler)
+      node.body = node.body.transform(self)
+      transform_many node.rescues
+
+      if node_ensure = node.ensure
+        node.ensure = node_ensure.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : Rescue)
+      node.body = node.body.transform(self)
+      transform_many node.types
+      node
+    end
+
+    def transform(node : Union)
+      transform_many node.types
+      node
+    end
+
+    def transform(node : Hierarchy)
+      node.name = node.name.transform(self)
+      node
+    end
+
+    def transform(node : Metaclass)
+      node.name = node.name.transform(self)
+      node
+    end
+
+    def transform(node : Arg)
+      if default_value = node.default_value
+        node.default_value = default_value.transform(self)
+      end
+
+      if restriction = node.restriction
+        node.restriction = restriction.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : BlockArg)
+      node.fun = node.fun.transform(self)
+      node
+    end
+
+    def transform(node : Fun)
+      transform_many node.inputs
+
+      if output = node.output
+        node.output = output.transform(self)
+      end
+
+      node
+    end
+
+    def transform(node : Block)
+      node.args.map! { |exp| exp.transform(self) as Var }
+      node.body = node.body.transform(self)
+      node
+    end
+
+    def transform(node : FunLiteral)
+      node.def.body = node.def.body.transform(self)
+      node
+    end
+
+    def transform(node : FunPointer)
+      if obj = node.obj
+        node.obj = obj.transform(self)
+      end
+      node
+    end
+
+    def transform(node : Return)
+      transform_many node.exps
+      node
+    end
+
+    def transform(node : Break)
+      transform_many node.exps
+      node
+    end
+
+    def transform(node : Next)
+      transform_many node.exps
+      node
+    end
+
+    def transform(node : Yield)
+      if scope = node.scope
+        node.scope = scope.transform(self)
+      end
+      transform_many node.exps
+      node
+    end
+
+    def transform(node : Include)
+      node.name = node.name.transform(self)
+      node
+    end
+
+    def transform(node : Extend)
+      node.name = node.name.transform(self)
+      node
+    end
+
+    def transform(node : RangeLiteral)
+      node.from = node.from.transform(self)
+      node.to = node.to.transform(self)
+      node
+    end
+
+    def transform(node : Assign)
+      node.target = node.target.transform(self)
+      node.value = node.value.transform(self)
+      node
+    end
+
+    def transform(node : Nop)
+      node
+    end
+
+    def transform(node : NilLiteral)
+      node
+    end
+
+    def transform(node : BoolLiteral)
+      node
+    end
+
+    def transform(node : NumberLiteral)
+      node
+    end
+
+    def transform(node : CharLiteral)
+      node
+    end
+
+    def transform(node : StringLiteral)
+      node
+    end
+
+    def transform(node : SymbolLiteral)
+      node
+    end
+
+    def transform(node : RegexLiteral)
+      node
+    end
+
+    def transform(node : Var)
+      node
+    end
+
+    def transform(node : MetaVar)
+      node
+    end
+
+    def transform(node : InstanceVar)
+      node
+    end
+
+    def transform(node : ClassVar)
+      node
+    end
+
+    def transform(node : Global)
+      node
+    end
+
+    def transform(node : Require)
+      node
+    end
+
+    def transform(node : Path)
+      node
+    end
+
+    def transform(node : Self)
+      node
+    end
+
+    def transform(node : LibDef)
+      node.body = node.body.transform(self)
+      node
+    end
+
+    def transform(node : FunDef)
+      if body = node.body
+        node.body = body.transform(self)
+      end
+      node
+    end
+
+    def transform(node : TypeDef)
+      node
+    end
+
+    def transform(node : StructDef)
+      node
+    end
+
+    def transform(node : UnionDef)
+      node
+    end
+
+    def transform(node : EnumDef)
+      node
+    end
+
+    def transform(node : ExternalVar)
+      node
+    end
+
+    def transform(node : IndirectRead)
+      node.obj = node.obj.transform(self)
+      node
+    end
+
+    def transform(node : IndirectWrite)
+      node.obj = node.obj.transform(self)
+      node.value = node.value.transform(self)
+      node
+    end
+
+    def transform(node : TypeOf)
+      transform_many node.expressions
+      node
+    end
+
+    def transform(node : Primitive)
+      node
+    end
+
+    def transform(node : Not)
+      node
+    end
+
+    def transform(node : TypeFilteredNode)
+      node
+    end
+
+    def transform(node : TupleLiteral)
+      transform_many node.exps
+      node
+    end
+
+    def transform(node : Cast)
+      node.obj = node.obj.transform(self)
+      node.to = node.to.transform(self)
+      node
+    end
+
+    def transform(node : DeclareVar)
+      node.var = node.var.transform(self)
+      node.declared_type = node.declared_type.transform(self)
+      node
+    end
+
+    def transform(node : Alias)
+      node.value = node.value.transform(self)
+      node
+    end
+
+    def transform(node : TupleIndexer)
+      node
+    end
+
+    def transform(node : Attribute)
+      node
+    end
+
+    def transform_many(exps)
+      exps.map! { |exp| exp.transform(self) } if exps
+    end
+  end
+end