introducing expressions and constants

not everything statement anymore (as in ruby)
basic statement tests working, rest havoc

lib/mom/instruction/slot_constant.rb

@@ -4,7 +4,7 @@ module Mom
   # the a is an instance variable on the current frame, and the frame is an instance
   # of the current message, so the effect is something like message.frame.a = 5
   # @left:  See SlotLoad, an array of symbols
-  # @right: A Constant from parse, ie an instance of classes in basc_value, like TrueStatement
+  # @right: A Constant from parse, ie an instance of classes in basc_value, like TrueConstant
   class SlotConstant < SlotLoad
 
     def initialize(left , right)

lib/vool/ruby_compiler.rb

@@ -38,31 +38,31 @@ module Vool
 
     #basic Values
     def on_self exp
-      SelfStatement.new
+      SelfExpression.new
     end
 
     def on_nil expression
-      NilStatement.new
+      NilConstant.new
     end
 
     def on_int expression
-      IntegerStatement.new(expression.children.first)
+      IntegerConstant.new(expression.children.first)
     end
 
     def on_float expression
-      FloatStatement.new(expression.children.first)
+      FloatConstant.new(expression.children.first)
     end
 
     def on_true expression
-      TrueStatement.new
+      TrueConstant.new
     end
 
     def on_false expression
-      FalseStatement.new
+      FalseConstant.new
     end
 
     def on_str expression
-      StringStatement.new(expression.children.first)
+      StringConstant.new(expression.children.first)
     end
     alias  :on_string :on_str
 
@@ -72,7 +72,7 @@ module Vool
     alias  :on_xstr :on_dstr
 
     def on_sym expression
-      SymbolStatement.new(expression.children.first)
+      SymbolConstant.new(expression.children.first)
     end
     alias  :on_string :on_str
 
@@ -151,7 +151,7 @@ module Vool
 
     def on_send statement
       kids = statement.children.dup
-      receiver = process(kids.shift) || SelfStatement.new
+      receiver = process(kids.shift) || SelfExpression.new
       name = kids.shift
       arguments = process_all(kids)
       SendStatement.new( name , receiver , arguments )
@@ -167,14 +167,14 @@ module Vool
 
     # this is a call to super without args (z = zero arity)
     def on_zsuper exp
-      SendStatement.new( nil , SuperStatement.new , nil)
+      SendStatement.new( nil , SuperExpression.new , nil)
     end
 
     # this is a call to super with args and
     # same name as current method, which is set later
     def on_super( statement )
       arguments = process_all(statement.children)
-      SendStatement.new( nil , SuperStatement.new , arguments)
+      SendStatement.new( nil , SuperExpression.new , arguments)
     end
 
     def on_assignment statement

lib/vool/statement.rb

@@ -10,6 +10,9 @@
 # Also, Vool is a typed tree, not abstract, so  there is a base class Statement
 #            and all it's derivation that make up the syntax tree
 #
+# Also Vool has expression and statements and simple syntax. So returns must be explicit
+# not everthing is just assignable, ifs can only test simple expressions etc (wip)
+#
 # This allows us to write compilers or passes of the compiler(s) as functions on the
 # classes.
 #
@@ -22,6 +25,13 @@ module Vool
   #
   class Statement
 
+    # after creation vool normalizes to ensure valid syntax and simplify
+    # also throw errors if violation
+    def normalize
+      return self
+    end
+
+    # flatten tree to array
     def collect(arr)
       arr << self
     end
@@ -51,6 +61,10 @@ module Vool
     def set_class( clazz )
     end
   end
+
+  class Expression
+  end
+
 end
 
 
@@ -61,7 +75,7 @@ require_relative "statements/class_statement"
 require_relative "statements/hash_statement"
 require_relative "statements/if_statement"
 require_relative "statements/logical_statement"
-require_relative "statements/local_statement"
+require_relative "statements/local_assignment"
 require_relative "statements/method_statement"
 require_relative "statements/return_statement"
 require_relative "statements/statements"

lib/vool/statements/assign_statement.rb

@@ -5,6 +5,14 @@ module Vool
     def initialize(name , value )
       @name , @value = name , value
     end
+
+    def normalize()
+      raise "not named left #{name}" unless @name.is_a?(Named)
+      raise "unsupported right #{value}" unless @name.is_a?(Named) or
+              @name.is_a?(SendStatement) or @name.is_a?(Constant)
+      self
+    end
+
     def collect(arr)
       @value.collect(arr)
       super

lib/vool/statements/basic_values.rb

@@ -4,13 +4,13 @@ module Vool
       Mom::SlotMove
     end
   end
-  class ConstantStatement < Statement
+  class Constant < Expression
     def slot_class
       Mom::SlotConstant
     end
   end
 
-  class IntegerStatement < ConstantStatement
+  class IntegerConstant < Constant
     attr_reader :value
     def initialize(value)
       @value = value
@@ -22,7 +22,7 @@ module Vool
       Parfait.object_space.get_class_by_name(:Integer).instance_type
     end
   end
-  class FloatStatement < ConstantStatement
+  class FloatConstant < Constant
     attr_reader :value
     def initialize(value)
       @value = value
@@ -31,22 +31,22 @@ module Vool
       true
     end
   end
-  class TrueStatement < ConstantStatement
+  class TrueConstant < Constant
     def ct_type
       Parfait.object_space.get_class_by_name(:True).instance_type
     end
   end
-  class FalseStatement < ConstantStatement
+  class FalseConstant < Constant
     def ct_type
       Parfait.object_space.get_class_by_name(:False).instance_type
     end
   end
-  class NilStatement < ConstantStatement
+  class NilConstant < Constant
     def ct_type
       Parfait.object_space.get_class_by_name(:Nil).instance_type
     end
   end
-  class SelfStatement < Statement
+  class SelfExpression < Expression
     attr_reader :clazz
     def set_class(clazz)
       @clazz = clazz
@@ -58,9 +58,9 @@ module Vool
       @clazz.instance_type
     end
   end
-  class SuperStatement < Statement
+  class SuperExpression < Statement
   end
-  class StringStatement < ConstantStatement
+  class StringConstant < Constant
     attr_reader :value
     def initialize(value)
       @value = value
@@ -72,7 +72,7 @@ module Vool
       Parfait.object_space.get_class_by_name(:Word).instance_type
     end
   end
-  class SymbolStatement < StringStatement
+  class SymbolConstant < StringConstant
     def ct_type
       Parfait.object_space.get_class_by_name(:Word).instance_type
     end

lib/vool/statements/hoister.rb

@@ -1,10 +0,0 @@
-module Vool
-  module Hoister
-    def hoist_condition( method )
-      return [@condition] if @condition.is_a?(Vool::Named)
-      local = method.create_tmp
-      assign = LocalAssignment.new( local , @condition)
-      [Vool::LocalVariable.new(local) , assign]
-    end
-  end
-end

lib/vool/statements/if_statement.rb

@@ -1,7 +1,7 @@
-require_relative "hoister"
+require_relative "normalizer"
 module Vool
   class IfStatement < Statement
-    include Hoister
+    include Normalizer
 
     attr_reader :condition , :if_true , :if_false
 
@@ -12,6 +12,14 @@ module Vool
       simplify_condition
     end
 
+    def normalize(method)
+      cond , rest = *normalize_name(@condition)
+      fals = @if_false ? @if_false.normalize(method) : nil
+      me = IfStatement.new(cond , @if_true.normalize(method), fals)
+      return me unless rest
+      rest << me
+    end
+
     def to_mom( method )
       if_true =   @if_true.to_mom( method )
       if_false =  @if_false ? @if_false.to_mom( method ) : nil

lib/vool/statements/normalizer.rb

@@ -0,0 +1,16 @@
+module Vool
+  module Normalizer
+    # given a something, determine if it is a Name
+    #
+    # Return a Name, and a possible rest that has a hoisted part of the statement
+    #
+    # eg  if( @var % 5) is not normalized
+    # but if(tmp_123) is with tmp_123 = @var % 5 hoited above the if
+    def normalize_name( method )
+      return [@condition] if @condition.is_a?(Named)
+      local = method.create_tmp
+      assign = LocalAssignment.new( local , @condition)
+      [LocalVariable.new(local) , assign]
+    end
+  end
+end

lib/vool/statements/send_statement.rb

@@ -96,8 +96,8 @@ module Vool
       [Mom::SlotMove.new([@dynamic, :cached_type] , [:receiver , :type])]
     end
     def build_method_cache_update(in_method)
-      receiver = StringStatement.new(@name)
-      resolve = SendStatement.new(:resolve_method , receiver , [SelfStatement.new])
+      receiver = StringConstant.new(@name)
+      resolve = SendStatement.new(:resolve_method , receiver , [SelfExpression.new])
       move_method = Mom::SlotMove.new([@dynamic, :cached_method] , [:receiver , :return])
       resolve.to_mom(in_method) << move_method
     end

lib/vool/statements/variables.rb

@@ -6,7 +6,7 @@ module Vool
     end
   end
 
-  class LocalVariable < Statement
+  class LocalVariable < Expression
     include Named
     def to_mom(method)
       if method.args_type.variable_index(@name)
@@ -18,7 +18,7 @@ module Vool
     end
   end
 
-  class InstanceVariable < Statement
+  class InstanceVariable < Expression
     include Named
     def to_mom(method)
       Mom::SlotDefinition.new(:message , [ :receiver , @name] )
@@ -29,11 +29,11 @@ module Vool
     end
   end
 
-  class ClassVariable < Statement
+  class ClassVariable < Expression
     include Named
   end
 
-  class ModuleName < Statement
+  class ModuleName < Expression
     include Named
   end
 end

lib/vool/statements/while_statement.rb

@@ -1,8 +1,8 @@
-require_relative "hoister"
+require_relative "normalizer"
 
 module Vool
   class WhileStatement < Statement
-    include Hoister
+    include Normalizer
     attr_reader :condition , :statements
 
     def initialize( condition , statements )
@@ -11,6 +11,13 @@ module Vool
       simplify_condition
     end
 
+    def normalize(method)
+      cond , rest = *normalize_name(@condition)
+      me = WhileStatement.new(cond , @statements.normalize(method))
+      return me unless rest
+      rest << me
+    end
+
     def to_mom( method )
       statements =   @statements.to_mom( method )
       condition , hoisted  = hoist_condition( method )