Merge branch 'flexible_conditionals'

Conflicts:
	lib/object.fy

bin/ifancy

@@ -58,14 +58,14 @@ load_history
 try {
   bnd = binding()
 
-  { Readline readline(">> ", true) } while_do: |line| {
+  while: { Readline readline(">> ", true) } do: |line| {
     HISTORY << line
-    double_or_empty?: line . if_true: {
+    if: (double_or_empty?: line) then: {
       Readline::HISTORY pop()
       HISTORY pop()
     }
 
-    line =~ /^\s*$/ if_false: {
+    unless: (line =~ /^\s*$/) do: {
       try {
         Fancy eval: line binding: bnd . inspect println
       } catch Exception => e {

examples/echo.fy

@@ -1,7 +1,7 @@
 # echo.fy
 # Outputs contents of files
 
-ARGV[1] if_do: |filename| {
+ARGV[1] if_true: |filename| {
  try {
     File open: filename modes: ['read] with: |f| {
       until: { f eof? } do: {

examples/game_of_life.fy

@@ -72,7 +72,7 @@ class World {
   def was_alive?: pos {
     "Indicates, if a cell ([row,column]) was alive in the last generation."
 
-    @last_alive[pos[0]] if_do: |row| {
+    @last_alive[pos[0]] if_true: |row| {
       row[pos[1]] == 1
     }
   }
@@ -115,7 +115,7 @@ class World {
     column = pos[1]
 
     neighbors = @offsets map: |o| {
-      @matrix[row + (o[0])] if_do: |r| {
+      @matrix[row + (o[0])] if_true: |r| {
         r[column + (o[1])]
       }
     }

lib/argv.fy

@@ -1,9 +1,9 @@
 def ARGV for_option: op_name do: block {
   "Runs a given block if an option is in ARGV."
 
-  ARGV index: op_name . if_do: |idx| {
+  ARGV index: op_name . if_true: |idx| {
     if: (block argcount > 0) then: {
-      ARGV[idx + 1] if_do: |arg| {
+      ARGV[idx + 1] if_true: |arg| {
         block call: [arg]
         ARGV remove_at: idx
         ARGV remove_at: idx

lib/block.fy

@@ -36,7 +36,7 @@ class Block {
 
   def while_true: work {
     {
-      call if_do: |val| {
+      call if_true: |val| {
         work call: [val]
       } else: {
         break

lib/boot.fy

@@ -25,6 +25,7 @@ require: "array"
 require: "tuple"
 require: "block"
 require: "iteration"
+require: "enumerator"
 require: "file"
 require: "directory"
 require: "fancy_spec"
@@ -46,4 +47,4 @@ require: "argv"
 
 require: "documentation"
 
-require: "package.fy"
+require: "package.fy"

lib/compiler/ast/class_def.fy

@@ -18,7 +18,7 @@ class Fancy AST {
     def bytecode: g {
       pos(g)
       docstring = body() body() shift_docstring
-      docstring if_do: {
+      docstring if_true: {
         setdoc = MessageSend new: @line \
                              message: (Identifier from: "for:append:" line: @line) \
                              to: (Identifier from: "Fancy::Documentation" line: @line) \

lib/compiler/ast/identifier.fy

@@ -25,10 +25,10 @@ class Fancy AST {
     }
 
     def method_name: receiver ruby_send: ruby (false) {
-      ruby || @ruby_ident if_do: {
+      ruby || @ruby_ident if_true: {
         @string to_sym()
       } else: {
-        @string =~ /:$/ . if_do: {
+        @string =~ /:$/ . if_true: {
           @string to_sym()
         } else: {
           ":" + @string . to_sym()

lib/compiler/ast/method_def.fy

@@ -27,10 +27,10 @@ class Fancy AST {
       g send(@access, 0)
       g pop()
 
-      @name to_s =~ /^initialize:(\S)+/ if_do: {
+      @name to_s =~ /^initialize:(\S)+/ if_true: {
         define_constructor_class_method: g
       }
-      @name to_s =~ /^unknown_message:with_params:$/ if_do: {
+      @name to_s =~ /^unknown_message:with_params:$/ if_true: {
         define_method_missing: g
       }
 

lib/documentation.fy

@@ -63,7 +63,7 @@ class Fancy Documentation {
       If obj has no documentation, one is created for it.
     """
     doc = for: obj
-    doc if_do: {
+    if: doc then: {
       doc docs << docstring
     } else: {
       doc  = for: obj is: docstring

lib/enumerable.fy

@@ -77,7 +77,7 @@ class FancyEnumerable {
     """
 
     each: |x| {
-      block call: [x] . if_do: |item| {
+      if: (block call: [x]) then: |item| {
         return item
       }
     }

lib/enumerator.fy

@@ -0,0 +1,77 @@
+class FancyEnumerator {
+  def initialize: @object {
+    @iterator = 'each:
+    rewind
+  }
+
+  def initialize: @object with: @iterator {
+    rewind
+  }
+
+  def next {
+    if: @peeked then: {
+      @peeked = false
+      @peek
+    } else: {
+      result = @fiber resume
+      if: (@fiber alive?) then: {
+        return result
+      } else: {
+        (Fancy StopIteration new: result) raise!
+      }
+    }
+  }
+
+  def peek {
+    """
+    Returns the next object in the FancyEnumerator, but doesn't move the
+    internal position forward.
+    When the position reaches the end, a Fancy StopIteration exception is
+    raised.
+
+    a = [1,2,3]
+    e = a to_enum
+    e next p #=> 1
+    e peek p #=> 2
+    e peek p #=> 2
+    e peek p #=> 2
+    e next p #=> 2
+    e next p #=> 3
+    e next p #=> raises Fancy StopIteration
+    """
+
+    unless: @peeked do: {
+      @peeked = true
+      @peek = @fiber resume
+      if: (@fiber alive?) then: {
+        return @peek
+      } else: {
+        (Fancy StopIteration new: result) raise!
+      }
+    }
+
+    return @peek
+  }
+
+  def rewind {
+    @peeked = false
+    @peek = nil
+
+    @fiber = Fiber new: {
+      param = |element| { yield: element }
+      @object send_message: @iterator with_params: [param]
+    }
+  }
+
+  def with: object each: block {
+    loop: {
+      try {
+        block call: [next, object]
+      } catch (Fancy StopIteration) => ex {
+        return object
+      }
+    }
+
+    return object
+  }
+}

lib/false_class.fy

@@ -1,41 +1,35 @@
 class FalseClass {
   "FalseClass. The class of the singleton @false value."
 
-  def if_true: then_block else: else_block {
-    "Calls @else_block."
-    else_block call
+  def FalseClass new {
+    # always return false singleton object when trying to create a new
+    # FalseClass instance
+    false
   }
 
   def if_true: block {
     "Returns @nil."
     nil
   }
 
-  def if_false: block {
-    "Calls @block."
-    block call
+  def if_true: then_block else: else_block {
+    "Calls @else_block."
+    else_block call
   }
 
-  def if_nil: block {
-    "Calls @block."
-    nil
+  def if_false: block {
+    block call: [self]
   }
 
-  def nil? {
-    "Returns @false."
-    false
+  def if_false: then_block else: else_block {
+    then_block call: [self]
   }
 
   def false? {
     "Returns @true."
     true
   }
 
-  def true? {
-    "Returns @false."
-    false
-  }
-
   def to_s {
     "Returns @false as a @String@."
     "false"

lib/fancy_spec.fy

@@ -29,7 +29,7 @@ class FancySpec {
   def it: spec_info_string for: method_name when: spec_block {
     test = SpecTest new: spec_info_string block: spec_block
     # try {
-    #   @test_obj method: method_name . if_do: |method| {
+    #   @test_obj method: method_name . if_true: |method| {
     #     method tests << test
     #   }
     # } catch MethodNotFoundError => e {

lib/fdoc.fy

@@ -284,8 +284,8 @@ class Fancy FDoc {
              method = method sub(/^:/, "")
            }
            sigil = ""
-           name =~ (Regexp.new("^#")) . if_do: { sigil = "<small>#</small>" }
-           type = n[1] include?(":") . if_do: {
+           name =~ (Regexp.new("^#")) . if_true: { sigil = "<small>#</small>" }
+           type = n[1] include?(":") . if_true: {
              if: (sigil == "") then: {
                "singleton-method-ref"
              } else: {

lib/iteration.fy

@@ -8,4 +8,53 @@ class Fancy {
     read_slots: ['return_value]
     def initialize: @return_value {}
   }
+
+  class StopIteration : StdError {
+    """
+    Raised to stop the iteration, in particular by Enumerator#next.
+    It is rescued by Block#loop.
+
+    Example:
+      {
+        'Hello println
+        StopIteration new raise!
+        'World println
+      } loop
+      'Done! println
+
+    Produces:
+
+      Hello
+      Done!
+    """
+
+    def initialize { @result = nil }
+    def initialize: @result { }
+
+    def result {
+      """
+      Returns the return value of the iterator.
+
+        o = Object new
+        def o each: block {
+          block call: 1
+          block call: 2
+          block call: 3
+          100
+        }
+
+        e = o to_enum
+        e next p #=> 1
+        e next p #=> 2
+        e next p #=> 3
+        try {
+          e next
+        } catch Fancy StopIteration => ex {
+          ex result p #=> 100
+        }
+      """
+
+      @result
+    }
+  }
 }

lib/main.fy

@@ -39,7 +39,7 @@ ARGV for_option: "-e" do: |eval_string| {
 }
 
 ARGV for_option: "-c" do: {
-  ARGV index: "-c" . if_do: |idx| {
+  ARGV index: "-c" . if_true: |idx| {
     ARGV[[idx + 1, -1]] each: |filename| {
       "Compiling " ++ filename println
       Fancy Compiler compile_file: filename to: nil line: 1 print: false
@@ -49,7 +49,7 @@ ARGV for_option: "-c" do: {
 }
 
 ARGV for_option: "-cv" do: {
-  ARGV index: "-cv" . if_do: |idx| {
+  ARGV index: "-cv" . if_true: |idx| {
     ARGV[[idx + 1, -1]] each: |filename| {
       "Compiling " ++ filename println
       Fancy Compiler compile_file: filename to: nil line: 1 print: true
@@ -77,14 +77,14 @@ ARGV for_option: "list-packages" do: {
 Fancy Package add_to_loadpath
 
 # Load a source file, if any given:
-ARGV first if_do: |file| {
+ARGV first if_true: |file| {
   try {
     Fancy CodeLoader load_compiled_file: file
   } catch Fancy Parser ParseError => e {
     e message println
   }
 }
 
-ARGV empty? if_do: {
+ARGV empty? if_true: {
   require: "../bin/ifancy"
 }