made array comprehensions into expressions

code.jaa

@@ -1,5 +1,4 @@
 # TODO: switch/case statements
-# Make array comprehensions expressions. (return the computed array).
 # Make arbitrary-length if else if else if chains possible.
 # Think of a name for this crazy thing.
 
@@ -37,7 +36,6 @@ exponents : [x => x., x => x * x., x => x * x * x.]
 # Conditionals and ternaries.
 if submarine.shields_up
   full_speed_ahead()
-# else if submarine.fully_loaded
   fire_torpedos()
 else
   run_away().
@@ -100,7 +98,6 @@ change_a_and_set_b: =>
 b: 20
 
 # Array comprehensions.
-print(food.capitalize()) for food in ['toast', 'wine', 'cheese'].
+supper: food.capitalize() for food in ['toast', 'cheese', 'wine'].
 
-cooler: ['soda', 'wine', 'lemonade']
-drink(bottle) for bottle, i in cooler if even(i).
+drink(bottle) for bottle, i in ['soda', 'wine', 'lemonade'] if even(i).

nodes.rb

@@ -36,10 +36,9 @@ class Node
   TAB = '  '
 
   def line_ending;      ';';    end
-
   def statement?;       false;  end
-
-  def custom_return?;   false;   end
+  def custom_return?;   false;  end
+  def custom_assign?;   false;  end
 
   def compile(indent='', scope=nil, opts={}); end
 end
@@ -196,8 +195,10 @@ class AssignNode < Node
     return "#{name} = #{value}" if @variable.properties?
     defined = scope.find(name)
     postfix = !defined && opts[:return] ? ";\n#{indent}return #{name}" : ''
-    name = "var #{name}" if !defined
-    "#{name} = #{@value.compile(indent, scope)}#{postfix}"
+    def_part = defined ? "" : "var #{name};\n#{indent}"
+    return def_part + @value.compile(indent, scope, opts.merge(:assign => name)) if @value.custom_assign?
+    def_part = defined ? name : "var #{name}"
+    "#{def_part} = #{@value.compile(indent, scope)}#{postfix}"
   end
 end
 
@@ -346,7 +347,11 @@ class ForNode < Node
     ''
   end
 
-  def statement?
+  def custom_return?
+    true
+  end
+
+  def custom_assign?
     true
   end
 
@@ -360,7 +365,22 @@ class ForNode < Node
     for_part    = "var #{ivar}=0, #{lvar}=#{svar}.length; #{ivar}<#{lvar}; #{ivar}++"
     var_part    = "\n#{indent + TAB}#{name_part} = #{svar}[#{ivar}];\n"
     index_part  = @index ? "#{indent + TAB}#{index_name} = #{ivar};\n" : ''
-    "#{source_part}\n#{indent}for (#{for_part}) {#{var_part}#{index_part}#{indent + TAB}#{@body.compile(indent + TAB, scope)};\n#{indent}}"
+
+    set_result    = ''
+    save_result   = ''
+    return_result = ''
+    if opts[:return] || opts[:assign]
+      rvar          = scope.free_variable
+      set_result    = "var #{rvar} = [];\n#{indent}"
+      save_result   = "#{rvar}[#{ivar}] = "
+      return_result = rvar
+      return_result = "#{opts[:assign]} = #{return_result}" if opts[:assign]
+      return_result = "return #{return_result}" if opts[:return]
+      return_result = "\n#{indent}#{return_result}"
+    end
+
+    body = @body.compile(indent + TAB, scope)
+    "#{source_part}\n#{indent}#{set_result}for (#{for_part}) {#{var_part}#{index_part}#{indent + TAB}#{save_result}#{body};\n#{indent}}#{return_result}"
   end
 end