initial commit of the mystery language

SYNTAX

@@ -0,0 +1,30 @@
+Every line is an expression. Multiple expressions on a single line can be
+separated by a ";" character.
+
+NUM:      1
+          1.0
+          
+STRING:   "hello"
+          'hello'
+          
+OBJECT:   {one : 1, two : 2}
+          
+ARRAY:    [1, 2, 3]
+          
+CODE:     a, b => a * b.
+          
+IF:       return x if x > 1
+            
+          if (x > 1) return x
+              
+ASSIGN:   a : b
+              
+LOGICAL:  x && y
+          x and y
+          x || y
+          x or y
+
+
+
+          
+

code.jaa

@@ -0,0 +1,40 @@
+# I'm a comment and I'm ok.
+# Return
+# Case
+
+square: x => x * x.
+
+sum: x, y => x + y.
+
+odd: x => x % 2 is 0.
+
+even: x => x % 2 aint 0.
+
+object_literal: {one: 1, two: 2, three: 3}
+
+multiline_object: {
+  pi: 3.14159
+  list: [1, 2, 3, 4]
+  three: 3
+  inner_obj: {
+    freedom: => _.freedom().
+  }
+}
+
+run_loop: =>
+  fire_events(e => e.stopPropagation().)
+  listen()
+  wait().
+
+if submarine.shields_up
+  full_speed_ahead()
+  weapons.fire_torpedos()
+else
+  run_away().
+
+eldest: if 25 > 21 then liz else marge.
+
+
+
+
+

documents.jaa

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+# Document Model
+dc.model.Document: dc.Model.extend({
+
+  constructor : attributes => this.base(attributes).
+
+  # For display, show either the highlighted search results, or the summary,
+  # if no highlights are available.
+  # The import process will take care of this in the future, but the inline
+  # version of the summary has all runs of whitespace squeezed out.
+  displaySummary : =>
+    text: this.get('highlight') or this.get('summary')
+    text ? text.replace(/\s+/g, ' ') else ''
+
+  # Return a list of the document's metadata. Think about caching this on the
+  # document by binding to Metadata, instead of on-the-fly.
+  metadata : =>
+    docId : this.id
+    _.select(Metadata.models(), (m =>
+      _.any(m.get('instances'), (i =>
+        i.document_id == docId
+      ))
+    ))
+
+  bookmark : pageNumber =>
+    bookmark : new dc.model.Bookmark({title : this.get('title'), page_number : pageNumber, document_id : this.id})
+    Bookmarks.create(bookmark)
+
+  # Inspect.
+  toString : =>
+    'Document ' + this.id + ' "' + this.get('title') + '"'
+
+})
+
+# Document Set
+dc.model.DocumentSet : dc.model.RESTfulSet.extend({
+
+  resource : 'documents'
+
+  SELECTION_CHANGED : 'documents:selection_changed'
+
+  constructor : options =>
+    this.base(options)
+    _.bindAll(this, 'downloadSelectedViewers', 'downloadSelectedPDF', 'downloadSelectedFullText')
+
+  selected      : => _.select(this.models(), m => m.get('selected'))
+
+  selectedIds   : => _.pluck(this.selected(), 'id')
+
+  countSelected : => this.selected().length
+
+  downloadSelectedViewers : =>
+    dc.app.download('/download/' + this.selectedIds().join('/') + '/document_viewer.zip');
+
+  downloadSelectedPDF : =>
+    return window.open(this.selected()[0].get('pdf_url')) if this.countSelected() <= 1
+    dc.app.download('/download/' + this.selectedIds().join('/') + '/document_pdfs.zip')
+
+  downloadSelectedFullText : =>
+    return window.open(this.selected()[0].get('full_text_url')) if this.countSelected() <= 1
+    dc.app.download('/download/' + this.selectedIds().join('/') + '/document_text.zip')
+
+  # We override "_onModelEvent" to fire selection changed events when documents
+  # change their selected state.
+  _onModelEvent : e, model =>
+    this.base(e, model)
+    fire : (e == dc.Model.CHANGED and model.hasChanged('selected'))
+    _.defer(_(this.fire).bind(this, this.SELECTION_CHANGED, this)) if fire
+  }
+
+})
+
+# The main set of Documents, used by the search tab.
+window.Documents : new dc.model.DocumentSet()
+
+# The set of documents that is used to look at a particular label.
+dc.app.LabeledDocuments : new dc.model.DocumentSet()

grammar.y

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+class Parser
+
+# Declare tokens produced by the lexer
+token IF ELSE THEN
+token NEWLINE
+token NUMBER
+token STRING
+token TRUE FALSE NULL
+token IDENTIFIER PROPERTY_ACCESS
+token CODE
+
+prechigh
+  nonassoc UMINUS NOT '!'
+  left     '*' '/' '%'
+  left     '+' '-'
+  left     '<=' '<' '>' '>='
+  right    '==' '!=' IS AINT
+  left     '&&' '||' AND OR
+  right    '-=' '+=' '/=' '*='
+preclow
+
+rule
+  # All rules are declared in this format:
+  #
+  #   RuleName:
+  #     OtherRule TOKEN AnotherRule    { code to run when this matches }
+  #   | OtherRule                      { ... }
+  #   ;
+  #
+  # In the code section (inside the {...} on the right):
+  # - Assign to "result" the value returned by the rule.
+  # - Use val[index of expression] to reference expressions on the left.
+
+
+  # All parsing will end in this rule, being the trunk of the AST.
+  Root:
+    /* nothing */                      { result = Nodes.new([]) }
+  | Expressions                        { result = val[0] }
+  ;
+
+  # Any list of expressions or method body, seperated by line breaks.
+  Expressions:
+    Expression                         { result = Nodes.new(val) }
+  | Expressions Terminator Expression  { result = val[0] << val[2] }
+  | Expressions Terminator             { result = Nodes.new([val[0]]) }
+  | Terminator Expressions             { result = Nodes.new([val[1]]) }
+  ;
+
+  # All types of expressions in our language
+  Expression:
+    Literal
+  | Variable
+  | Call
+  | Assign
+  | Object
+  | Code
+  | Operation
+  | Array
+  | If
+  ;
+
+  # All tokens that can terminate an expression
+  Terminator:
+    "\n"
+  | ";"
+  ;
+
+  # All hard-coded values
+  Literal:
+    NUMBER                        { result = LiteralNode.new(val[0]) }
+  | STRING                        { result = LiteralNode.new(val[0]) }
+  | TRUE                          { result = LiteralNode.new(true) }
+  | FALSE                         { result = LiteralNode.new(false) }
+  | NULL                          { result = LiteralNode.new(nil) }
+  ;
+
+  # Assign to a variable
+  Assign:
+    Variable ":" Expression       { result = AssignNode.new(val[0], val[2]) }
+  ;
+
+  # Assignment within an object literal.
+  AssignObj:
+    IDENTIFIER ":" Expression     { result = AssignNode.new(val[0], val[2], :object) }
+  ;
+
+  # Arithmetic and logical operators
+  # For Ruby's Operator precedence, see:
+  # https://www.cs.auckland.ac.nz/references/ruby/ProgrammingRuby/language.html
+  Operation:
+    '!' Expression              { result = OpNode.new(val[0], val[1]) }
+  | '-' Expression = UMINUS     { result = OpNode.new(val[0], val[1]) }
+  | NOT Expression              { result = OpNode.new(val[0], val[1]) }
+
+
+  | Expression '*' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '/' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '%' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+
+  | Expression '+' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '-' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+
+  | Expression '<=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '<' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '>' Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '>=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+
+  | Expression '==' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '!=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression IS Expression    { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression AINT Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+
+  | Expression '&&' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '||' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression AND Expression   { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression OR Expression    { result = OpNode.new(val[1], val[0], val[2]) }
+
+  # Add ternary?
+
+  | Expression '-=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '+=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '/=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  | Expression '*=' Expression  { result = OpNode.new(val[1], val[0], val[2]) }
+  # Add ||= &&=
+  ;
+
+
+  # Method definition
+  Code:
+    "=>" Expressions "."     { result = CodeNode.new([], val[1]) }
+  | ParamList
+      "=>" Expressions "."   { result = CodeNode.new(val[0], val[2]) }
+  ;
+
+  ParamList:
+    /* nothing */                 { result = [] }
+  | IDENTIFIER                    { result = val }
+  | ParamList "," IDENTIFIER      { result = val[0] << val[2] }
+  ;
+
+  Variable:
+    IDENTIFIER                              { result = VariableNode.new(val) }
+  | Variable PROPERTY_ACCESS IDENTIFIER     { result = val[0] << val[2] }
+  ;
+
+  Object:
+    "{" "}"                       { result = ObjectNode.new([]) }
+  | "{" AssignList "}"            { result = ObjectNode.new(val[1]) }
+  | "{" Terminator AssignList
+        Terminator "}"            { result = ObjectNode.new(val[2]) }
+  ;
+
+  AssignList:
+    /* nothing */                     { result = []}
+  | AssignObj                         { result = val }
+  | AssignList "," AssignObj          { result = val[0] << val[2] }
+  | AssignList Terminator AssignObj   { result = val[0] << val[2] }
+  ;
+
+  # A method call.
+  Call:
+    Variable "(" ArgList ")"          { result = CallNode.new(val[0], val[2]) }
+  ;
+
+  # An Array.
+  Array:
+    "[" ArgList "]"                   { result = ArrayNode.new(val[1]) }
+  ;
+
+  # A list of arguments to a method call.
+  ArgList:
+    /* nothing */                 { result = [] }
+  | Expression                    { result = val }
+  | ArgList "," Expression        { result = val[0] << val[2] }
+  ;
+
+  If:
+    IF Expression
+       THEN Expression "."              { result = TernaryNode.new(val[1], val[3]) }
+  | IF Expression Terminator
+       Expressions "."                  { result = IfNode.new(val[1], val[3]) }
+  | IF Expression
+       THEN Expression
+       ELSE Expression "."              { result = TernaryNode.new(val[1], val[3], val[5]) }
+  | IF Expression Terminator
+       Expressions Terminator
+       ELSE Expressions "."             { result = IfNode.new(val[1], val[3], val[6]) }
+  ;
+
+end
+
+---- header
+  require "lexer"
+  require "nodes"
+
+---- inner
+  def parse(code, show_tokens=false)
+    # @yydebug = true
+    @tokens = Lexer.new.tokenize(code)
+    puts @tokens.inspect if show_tokens
+    do_parse
+  end
+
+  def next_token
+    @tokens.shift
+  end

lexer.rb

@@ -0,0 +1,90 @@
+class Lexer
+
+  KEYWORDS   = ["if", "else", "then",
+                "true", "false", "null",
+                "and", "or", "is", "aint", "not"]
+
+  IDENTIFIER = /\A([a-zA-Z$_]\w*)/
+  NUMBER     = /\A([0-9]+(\.[0-9]+)?)/
+  STRING     = /\A["'](.*?)["']/
+  OPERATOR   = /\A([+\*&|\/\-%=<>]+)/
+  WHITESPACE = /\A([ \t\r]+)/
+  NEWLINE    = /\A([\r\n]+)/
+  COMMENT    = /\A(#[^\r\n]*)/
+  CODE       = /\A(=>)/
+
+  # This is how to implement a very simple scanner.
+  # Scan one caracter at the time until you find something to parse.
+  def tokenize(code)
+    @code = code.chomp    # Cleanup code by remove extra line breaks
+    @i = 0                # Current character position we're parsing
+    @tokens = []          # Collection of all parsed tokens in the form [:TOKEN_TYPE, value]
+    while @i < @code.length
+      @chunk = @code[@i..-1]
+      extract_next_token
+    end
+    @tokens
+  end
+
+  def extract_next_token
+    return if identifier_token
+    return if number_token
+    return if string_token
+    return if remove_comment
+    return if whitespace_token
+    return    literal_token
+  end
+
+  # Matching if, print, method names, etc.
+  def identifier_token
+    return false unless identifier = @chunk[IDENTIFIER, 1]
+    # Keywords are special identifiers tagged with their own name, 'if' will result
+    # in an [:IF, "if"] token
+    tag = KEYWORDS.include?(identifier) ? identifier.upcase.to_sym : :IDENTIFIER
+    if tag == :IDENTIFIER && @tokens[-1] && @tokens[-1][1] == '.'
+      @tokens[-1] = [:PROPERTY_ACCESS, '.']
+    end
+    @tokens << [tag, identifier]
+    @i += identifier.length
+  end
+
+  def number_token
+    return false unless number = @chunk[NUMBER, 1]
+    float = number.include?('.')
+    @tokens << [:NUMBER, float ? number.to_f : number.to_i]
+    @i += number.length
+  end
+
+  def string_token
+    return false unless string = @chunk[STRING, 1]
+    @tokens << [:STRING, string]
+    @i += string.length + 2
+  end
+
+  def remove_comment
+    return false unless comment = @chunk[COMMENT, 1]
+    @i += comment.length
+  end
+
+  # Ignore whitespace
+  def whitespace_token
+    return false unless whitespace = @chunk[WHITESPACE, 1]
+    @i += whitespace.length
+  end
+
+  # We treat all other single characters as a token. Eg.: ( ) , . !
+  # Multi-character operators are also literal tokens, so that Racc can assign
+  # the proper order of operations. Multiple newlines get merged.
+  def literal_token
+    value = @chunk[NEWLINE, 1]
+    if value
+      @tokens << ["\n", "\n"] unless @tokens.last && @tokens.last[0] == "\n"
+      return @i += value.length
+    end
+    value = @chunk[OPERATOR, 1]
+    value ||= @chunk[0,1]
+    @tokens << [value, value]
+    @i += value.length
+  end
+
+end

lexer_test.rb

@@ -0,0 +1,2 @@
+require "lexer"
+p Lexer.new.tokenize(File.read('code.jaa'))

nodes.rb

@@ -0,0 +1,176 @@
+# Tabs are two spaces for pretty-printing.
+TAB = '  '
+
+# Collection of nodes each one representing an expression.
+class Nodes
+  attr_reader :nodes
+  def initialize(nodes)
+    @nodes = nodes
+  end
+
+  def <<(node)
+    @nodes << node
+    self
+  end
+
+  # Flatten redundant nested node lists until we have multiple nodes on the
+  # same level to work with.
+  def reduce
+    return nodes.first.reduce if nodes.length == 1 && nodes.first.is_a?(Nodes)
+    nodes
+  end
+
+  def compile(indent='')
+    reduce.map { |node|
+      indent + node.compile(indent) + (node.is_a?(IfNode) ? '' : ';')
+    }.join("\n")
+  end
+end
+
+# Literals are static values that have a Ruby representation, eg.: a string, a number,
+# true, false, nil, etc.
+class LiteralNode
+  def initialize(value)
+    @value = value
+  end
+
+  def compile(indent)
+    @value.to_s
+  end
+end
+
+# Node of a method call or local variable access, can take any of these forms:
+#
+#   method # this form can also be a local variable
+#   method(argument1, argument2)
+#   receiver.method
+#   receiver.method(argument1, argument2)
+#
+class CallNode
+  def initialize(variable, arguments=[])
+    @variable, @arguments = variable, arguments
+  end
+
+  def compile(indent)
+    args = @arguments.map{|a| a.compile(indent) }.join(', ')
+    "#{@variable.compile(indent)}(#{args})"
+  end
+end
+
+class VariableNode
+  def initialize(name)
+    @name = name
+    @properties = []
+  end
+
+  def <<(other)
+    @properties << other
+    self
+  end
+
+  def compile(indent)
+    [@name, @properties].flatten.join('.')
+  end
+end
+
+# Setting the value of a local variable.
+class AssignNode
+  def initialize(variable, value, context=nil)
+    @variable, @value, @context = variable, value, context
+  end
+
+  def compile(indent)
+    return "#{@variable}: #{@value.compile(indent + TAB)}" if @context == :object
+    "var #{@variable.compile(indent)} = #{@value.compile(indent)}"
+  end
+end
+
+# Simple Arithmetic and logical operations
+class OpNode
+  CONVERSIONS = {
+    "=="    => "===",
+    "!="    => "!==",
+    'and'   => '&&',
+    'or'    => '||',
+    'is'    => '===',
+    "aint"  => "!==",
+    'not'   => '!',
+  }
+
+  def initialize(operator, first, second=nil)
+    @first, @second = first, second
+    @operator = CONVERSIONS[operator] || operator
+  end
+
+  def unary?
+    @second.nil?
+  end
+
+  def compile(indent)
+    "(#{@first.compile(indent)} #{@operator} #{@second.compile(indent)})"
+  end
+end
+
+# Method definition.
+class CodeNode
+  def initialize(params, body)
+    @params = params
+    @body = body
+  end
+
+  def compile(indent)
+    nodes = @body.reduce
+    exprs = nodes.map {|n| n.compile(indent + TAB) }
+    exprs[-1] = "return #{exprs[-1]};"
+    exprs = exprs.map {|e| indent + TAB + e }
+    "function(#{@params.join(', ')}) {\n#{exprs.join(";\n")}\n#{indent}}"
+  end
+end
+
+class ObjectNode
+  def initialize(properties = [])
+    @properties = properties
+  end
+
+  def compile(indent)
+    props = @properties.map {|p| indent + TAB + p.compile(indent) }.join(",\n")
+    "{\n#{props}\n#{indent}}"
+  end
+end
+
+class ArrayNode
+  def initialize(objects=[])
+    @objects = objects
+  end
+
+  def compile(indent)
+    objects = @objects.map {|o| o.compile(indent) }.join(', ')
+    "[#{objects}]"
+  end
+end
+
+# "if-else" control structure. Look at this node if you want to implement other control
+# structures like while, for, loop, etc.
+class IfNode
+  def initialize(condition, body, else_body=nil)
+    @condition, @body, @else_body = condition, body, else_body
+  end
+
+  def compile(indent)
+    if_part   = "if (#{@condition.compile(indent)}) {\n#{@body.compile(indent + TAB)}\n#{indent}}"
+    else_part = @else_body ? " else {\n#{@else_body.compile(indent + TAB)}\n#{indent}}" : ''
+    if_part + else_part
+  end
+end
+
+class TernaryNode
+  def initialize(condition, body, else_body=nil)
+    @condition, @body, @else_body = condition, body, else_body
+  end
+
+  def compile(indent)
+    if_part   = "#{@condition.compile(indent)} ? #{@body.compile(indent)}"
+    else_part = @else_body ? "#{@else_body.compile(indent)}" : 'null'
+    "#{if_part} : #{else_part}"
+  end
+end

parser_test.rb

@@ -0,0 +1,19 @@
+# Recompile the Parser.
+# With debugging and verbose: -v -g
+`racc -o parser.rb grammar.y`
+
+# Parse and print "code.jaa".
+require "parser.rb"
+js = Parser.new.parse(File.read('code.jaa')).compile
+puts "\n\n"
+puts js
+
+# Pipe compiled JS through JSLint.
+puts "\n\n"
+require 'open3'
+stdin, stdout, stderr = Open3.popen3('/Users/jashkenas/Library/Application\ Support/TextMate/Bundles/JavaScript\ Tools.tmbundle/Support/bin/jsl -nologo -stdin')
+stdin.write(js)
+stdin.close
+puts stdout.read
+stdout.close
+stderr.close

underscore.jaa

@@ -0,0 +1,610 @@
+# Underscore.js
+# (c) 2009 Jeremy Ashkenas, DocumentCloud Inc.
+# Underscore is freely distributable under the terms of the MIT license.
+# Portions of Underscore are inspired by or borrowed from Prototype.js,
+# Oliver Steele's Functional, and John Resig's Micro-Templating.
+# For all details and documentation:
+# http://documentcloud.github.com/underscore/
+
+=>
+
+  # ------------------------- Baseline setup ---------------------------------
+
+  # Establish the root object, "window" in the browser, or "global" on the server.
+  root = this
+
+  # Save the previous value of the "_" variable.
+  previousUnderscore = root._
+
+  # If Underscore is called as a function, it returns a wrapped object that
+  # can be used OO-style. This wrapper holds altered versions of all the
+  # underscore functions. Wrapped objects may be chained.
+  wrapper = (obj => this._wrapped = obj)
+
+  # Establish the object that gets thrown to break out of a loop iteration.
+  breaker = typeof StopIteration !== 'undefined' ? StopIteration : '__break__'
+
+  # Create a safe reference to the Underscore object for reference below.
+  _ = root._ = obj => new wrapper(obj)
+
+  # Export the Underscore object for CommonJS.
+  exports._ = _ if typeof exports !== 'undefined'
+
+  # Create quick reference variables for speed access to core prototypes.
+  slice                 = Array.prototype.slice
+  unshift               = Array.prototype.unshift
+  toString              = Object.prototype.toString
+  hasOwnProperty        = Object.prototype.hasOwnProperty
+  propertyIsEnumerable  = Object.prototype.propertyIsEnumerable
+
+  # Current version.
+  _.VERSION = '0.5.1'
+
+  # ------------------------ Collection Functions: ---------------------------
+
+  # The cornerstone, an each implementation.
+  # Handles objects implementing forEach, arrays, and raw objects.
+  _.each = obj, iterator, context =>
+    index = 0
+    try
+      return obj.forEach(iterator, context) if obj.forEach
+      canLoop = _.isArray(obj) or _.isArguments(obj)
+      return for (i=0, l=obj.length; i<l; i++) iterator.call(context, obj[i], i, obj) if canLoop
+      keys = _.keys(obj)
+      l    = keys.length
+      for (var i=0; i<l; i++) iterator.call(context, obj[keys[i]], keys[i], obj)
+    catch(e)
+      throw e if (e != breaker)
+    return obj;
+
+  # Return the results of applying the iterator to each element. Use JavaScript
+  # 1.6's version of map, if possible.
+  _.map = obj, iterator, context =>
+    return obj.map(iterator, context) if (obj and _.isFunction(obj.map))
+    results = []
+    _.each(obj, (value, index, list =>
+      results.push(iterator.call(context, value, index, list))
+    ))
+    results
+
+  # Reduce builds up a single result from a list of values. Also known as
+  # inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
+  _.reduce = obj, memo, iterator, context =>
+    return obj.reduce(_.bind(iterator, context), memo) if (obj and _.isFunction(obj.reduce))
+    _.each(obj, (value, index, list =>
+      memo = iterator.call(context, memo, value, index, list)
+    ))
+    memo
+
+  # The right-associative version of reduce, also known as foldr. Uses
+  # JavaScript 1.8's version of reduceRight, if available.
+  _.reduceRight = function(obj, memo, iterator, context) {
+    if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
+    var reversed = _.clone(_.toArray(obj)).reverse();
+    _.each(reversed, function(value, index) {
+      memo = iterator.call(context, memo, value, index, obj);
+    });
+    return memo;
+  };
+
+  # Return the first value which passes a truth test.
+  _.detect = function(obj, iterator, context) {
+    var result;
+    _.each(obj, function(value, index, list) {
+      if (iterator.call(context, value, index, list)) {
+        result = value;
+        _.breakLoop();
+      }
+    });
+    return result;
+  };
+
+  # Return all the elements that pass a truth test. Use JavaScript 1.6's
+  # filter(), if it exists.
+  _.select = function(obj, iterator, context) {
+    if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
+    var results = [];
+    _.each(obj, function(value, index, list) {
+      iterator.call(context, value, index, list) && results.push(value);
+    });
+    return results;
+  };
+
+  # Return all the elements for which a truth test fails.
+  _.reject = function(obj, iterator, context) {
+    var results = [];
+    _.each(obj, function(value, index, list) {
+      !iterator.call(context, value, index, list) && results.push(value);
+    });
+    return results;
+  };
+
+  # Determine whether all of the elements match a truth test. Delegate to
+  # JavaScript 1.6's every(), if it is present.
+  _.all = function(obj, iterator, context) {
+    iterator = iterator || _.identity;
+    if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
+    var result = true;
+    _.each(obj, function(value, index, list) {
+      if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop();
+    });
+    return result;
+  };
+
+  # Determine if at least one element in the object matches a truth test. Use
+  # JavaScript 1.6's some(), if it exists.
+  _.any = function(obj, iterator, context) {
+    iterator = iterator || _.identity;
+    if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
+    var result = false;
+    _.each(obj, function(value, index, list) {
+      if (result = iterator.call(context, value, index, list)) _.breakLoop();
+    });
+    return result;
+  };
+
+  # Determine if a given value is included in the array or object,
+  # based on '==='.
+  _.include = function(obj, target) {
+    if (_.isArray(obj)) return _.indexOf(obj, target) != -1;
+    var found = false;
+    _.each(obj, function(value) {
+      if (found = value === target) _.breakLoop();
+    });
+    return found;
+  };
+
+  # Invoke a method with arguments on every item in a collection.
+  _.invoke = function(obj, method) {
+    var args = _.rest(arguments, 2);
+    return _.map(obj, function(value) {
+      return (method ? value[method] : value).apply(value, args);
+    });
+  };
+
+  # Convenience version of a common use case of map: fetching a property.
+  _.pluck = function(obj, key) {
+    return _.map(obj, function(value){ return value[key]; });
+  };
+
+  # Return the maximum item or (item-based computation).
+  _.max = function(obj, iterator, context) {
+    if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
+    var result = {computed : -Infinity};
+    _.each(obj, function(value, index, list) {
+      var computed = iterator ? iterator.call(context, value, index, list) : value;
+      computed >= result.computed && (result = {value : value, computed : computed});
+    });
+    return result.value;
+  };
+
+  # Return the minimum element (or element-based computation).
+  _.min = function(obj, iterator, context) {
+    if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
+    var result = {computed : Infinity};
+    _.each(obj, function(value, index, list) {
+      var computed = iterator ? iterator.call(context, value, index, list) : value;
+      computed < result.computed && (result = {value : value, computed : computed});
+    });
+    return result.value;
+  };
+
+  # Sort the object's values by a criteria produced by an iterator.
+  _.sortBy = function(obj, iterator, context) {
+    return _.pluck(_.map(obj, function(value, index, list) {
+      return {
+        value : value,
+        criteria : iterator.call(context, value, index, list)
+      };
+    }).sort(function(left, right) {
+      var a = left.criteria, b = right.criteria;
+      return a < b ? -1 : a > b ? 1 : 0;
+    }), 'value');
+  };
+
+  # Use a comparator function to figure out at what index an object should
+  # be inserted so as to maintain order. Uses binary search.
+  _.sortedIndex = function(array, obj, iterator) {
+    iterator = iterator || _.identity;
+    var low = 0, high = array.length;
+    while (low < high) {
+      var mid = (low + high) >> 1;
+      iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid;
+    }
+    return low;
+  };
+
+  # Convert anything iterable into a real, live array.
+  _.toArray = function(iterable) {
+    if (!iterable)                return [];
+    if (iterable.toArray)         return iterable.toArray();
+    if (_.isArray(iterable))      return iterable;
+    if (_.isArguments(iterable))  return slice.call(iterable);
+    return _.map(iterable, function(val){ return val; });
+  };
+
+  # Return the number of elements in an object.
+  _.size = function(obj) {
+    return _.toArray(obj).length;
+  };
+
+  /*-------------------------- Array Functions: ------------------------------*/
+
+  # Get the first element of an array. Passing "n" will return the first N
+  # values in the array. Aliased as "head". The "guard" check allows it to work
+  # with _.map.
+  _.first = function(array, n, guard) {
+    return n && !guard ? slice.call(array, 0, n) : array[0];
+  };
+
+  # Returns everything but the first entry of the array. Aliased as "tail".
+  # Especially useful on the arguments object. Passing an "index" will return
+  # the rest of the values in the array from that index onward. The "guard"
+   //check allows it to work with _.map.
+  _.rest = function(array, index, guard) {
+    return slice.call(array, _.isUndefined(index) || guard ? 1 : index);
+  };
+
+  # Get the last element of an array.
+  _.last = function(array) {
+    return array[array.length - 1];
+  };
+
+  # Trim out all falsy values from an array.
+  _.compact = function(array) {
+    return _.select(array, function(value){ return !!value; });
+  };
+
+  # Return a completely flattened version of an array.
+  _.flatten = function(array) {
+    return _.reduce(array, [], function(memo, value) {
+      if (_.isArray(value)) return memo.concat(_.flatten(value));
+      memo.push(value);
+      return memo;
+    });
+  };
+
+  # Return a version of the array that does not contain the specified value(s).
+  _.without = function(array) {
+    var values = _.rest(arguments);
+    return _.select(array, function(value){ return !_.include(values, value); });
+  };
+
+  # Produce a duplicate-free version of the array. If the array has already
+  # been sorted, you have the option of using a faster algorithm.
+  _.uniq = function(array, isSorted) {
+    return _.reduce(array, [], function(memo, el, i) {
+      if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) memo.push(el);
+      return memo;
+    });
+  };
+
+  # Produce an array that contains every item shared between all the
+  # passed-in arrays.
+  _.intersect = function(array) {
+    var rest = _.rest(arguments);
+    return _.select(_.uniq(array), function(item) {
+      return _.all(rest, function(other) {
+        return _.indexOf(other, item) >= 0;
+      });
+    });
+  };
+
+  # Zip together multiple lists into a single array -- elements that share
+  # an index go together.
+  _.zip = function() {
+    var args = _.toArray(arguments);
+    var length = _.max(_.pluck(args, 'length'));
+    var results = new Array(length);
+    for (var i=0; i<length; i++) results[i] = _.pluck(args, String(i));
+    return results;
+  };
+
+  # If the browser doesn't supply us with indexOf (I'm looking at you, MSIE),
+  # we need this function. Return the position of the first occurence of an
+  # item in an array, or -1 if the item is not included in the array.
+  _.indexOf = function(array, item) {
+    if (array.indexOf) return array.indexOf(item);
+    for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i;
+    return -1;
+  };
+
+  # Provide JavaScript 1.6's lastIndexOf, delegating to the native function,
+  # if possible.
+  _.lastIndexOf = function(array, item) {
+    if (array.lastIndexOf) return array.lastIndexOf(item);
+    var i = array.length;
+    while (i--) if (array[i] === item) return i;
+    return -1;
+  };
+
+  # Generate an integer Array containing an arithmetic progression. A port of
+  # the native Python range() function. See:
+  # http://docs.python.org/library/functions.html#range
+  _.range = function(start, stop, step) {
+    var a     = _.toArray(arguments);
+    var solo  = a.length <= 1;
+    var start = solo ? 0 : a[0], stop = solo ? a[0] : a[1], step = a[2] || 1;
+    var len   = Math.ceil((stop - start) / step);
+    if (len <= 0) return [];
+    var range = new Array(len);
+    for (var i = start, idx = 0; true; i += step) {
+      if ((step > 0 ? i - stop : stop - i) >= 0) return range;
+      range[idx++] = i;
+    }
+  };
+
+  /* ----------------------- Function Functions: -----------------------------*/
+
+  # Create a function bound to a given object (assigning 'this', and arguments,
+  # optionally). Binding with arguments is also known as 'curry'.
+  _.bind = function(func, obj) {
+    var args = _.rest(arguments, 2);
+    return function() {
+      return func.apply(obj || root, args.concat(_.toArray(arguments)));
+    };
+  };
+
+  # Bind all of an object's methods to that object. Useful for ensuring that
+  # all callbacks defined on an object belong to it.
+  _.bindAll = function(obj) {
+    var funcs = _.rest(arguments);
+    if (funcs.length == 0) funcs = _.functions(obj);
+    _.each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
+    return obj;
+  };
+
+  # Delays a function for the given number of milliseconds, and then calls
+  # it with the arguments supplied.
+  _.delay = function(func, wait) {
+    var args = _.rest(arguments, 2);
+    return setTimeout(function(){ return func.apply(func, args); }, wait);
+  };
+
+  # Defers a function, scheduling it to run after the current call stack has
+  # cleared.
+  _.defer = function(func) {
+    return _.delay.apply(_, [func, 1].concat(_.rest(arguments)));
+  };
+
+  # Returns the first function passed as an argument to the second,
+  # allowing you to adjust arguments, run code before and after, and
+  # conditionally execute the original function.
+  _.wrap = function(func, wrapper) {
+    return function() {
+      var args = [func].concat(_.toArray(arguments));
+      return wrapper.apply(wrapper, args);
+    };
+  };
+
+  # Returns a function that is the composition of a list of functions, each
+  # consuming the return value of the function that follows.
+  _.compose = function() {
+    var funcs = _.toArray(arguments);
+    return function() {
+      var args = _.toArray(arguments);
+      for (var i=funcs.length-1; i >= 0; i--) {
+        args = [funcs[i].apply(this, args)];
+      }
+      return args[0];
+    };
+  };
+
+  /* ------------------------- Object Functions: ---------------------------- */
+
+  # Retrieve the names of an object's properties.
+  _.keys = function(obj) {
+    if(_.isArray(obj)) return _.range(0, obj.length);
+    var keys = [];
+    for (var key in obj) if (hasOwnProperty.call(obj, key)) keys.push(key);
+    return keys;
+  };
+
+  # Retrieve the values of an object's properties.
+  _.values = function(obj) {
+    return _.map(obj, _.identity);
+  };
+
+  # Return a sorted list of the function names available in Underscore.
+  _.functions = function(obj) {
+    return _.select(_.keys(obj), function(key){ return _.isFunction(obj[key]); }).sort();
+  };
+
+  # Extend a given object with all of the properties in a source object.
+  _.extend = function(destination, source) {
+    for (var property in source) destination[property] = source[property];
+    return destination;
+  };
+
+  # Create a (shallow-cloned) duplicate of an object.
+  _.clone = function(obj) {
+    if (_.isArray(obj)) return obj.slice(0);
+    return _.extend({}, obj);
+  };
+
+  # Perform a deep comparison to check if two objects are equal.
+  _.isEqual = function(a, b) {
+    # Check object identity.
+    if (a === b) return true;
+    # Different types?
+    var atype = typeof(a), btype = typeof(b);
+    if (atype != btype) return false;
+    # Basic equality test (watch out for coercions).
+    if (a == b) return true;
+    # One is falsy and the other truthy.
+    if ((!a && b) || (a && !b)) return false;
+    # One of them implements an isEqual()?
+    if (a.isEqual) return a.isEqual(b);
+    # Check dates' integer values.
+    if (_.isDate(a) && _.isDate(b)) return a.getTime() === b.getTime();
+    # Both are NaN?
+    if (_.isNaN(a) && _.isNaN(b)) return true;
+    # Compare regular expressions.
+    if (_.isRegExp(a) && _.isRegExp(b))
+      return a.source     === b.source &&
+             a.global     === b.global &&
+             a.ignoreCase === b.ignoreCase &&
+             a.multiline  === b.multiline;
+    # If a is not an object by this point, we can't handle it.
+    if (atype !== 'object') return false;
+    # Check for different array lengths before comparing contents.
+    if (a.length && (a.length !== b.length)) return false;
+    # Nothing else worked, deep compare the contents.
+    var aKeys = _.keys(a), bKeys = _.keys(b);
+    # Different object sizes?
+    if (aKeys.length != bKeys.length) return false;
+    # Recursive comparison of contents.
+    for (var key in a) if (!_.isEqual(a[key], b[key])) return false;
+    return true;
+  };
+
+  # Is a given array or object empty?
+  _.isEmpty = function(obj) {
+    return _.keys(obj).length == 0;
+  };
+
+  # Is a given value a DOM element?
+  _.isElement = function(obj) {
+    return !!(obj && obj.nodeType == 1);
+  };
+
+  # Is a given variable an arguments object?
+  _.isArguments = function(obj) {
+    return obj && _.isNumber(obj.length) && !_.isArray(obj) && !propertyIsEnumerable.call(obj, 'length');
+  };
+
+  # Is the given value NaN -- this one is interesting. NaN != NaN, and
+  # isNaN(undefined) == true, so we make sure it's a number first.
+  _.isNaN = function(obj) {
+    return _.isNumber(obj) && isNaN(obj);
+  };
+
+  # Is a given value equal to null?
+  _.isNull = function(obj) {
+    return obj === null;
+  };
+
+  # Is a given variable undefined?
+  _.isUndefined = function(obj) {
+    return typeof obj == 'undefined';
+  };
+
+  # Invokes interceptor with the obj, and then returns obj.
+  # The primary purpose of this method is to "tap into" a method chain, in order to perform operations on intermediate results within the chain.
+  _.tap = function(obj, interceptor) {
+    interceptor(obj);
+    return obj;
+  }
+
+  # Define the isArray, isDate, isFunction, isNumber, isRegExp, and isString
+  # functions based on their toString identifiers.
+  var types = ['Array', 'Date', 'Function', 'Number', 'RegExp', 'String'];
+  for (var i=0, l=types.length; i<l; i++) {
+    (function() {
+      var identifier = '[object ' + types[i] + ']';
+      _['is' + types[i]] = function(obj) { return toString.call(obj) == identifier; };
+    })();
+  }
+
+  /* -------------------------- Utility Functions: -------------------------- */
+
+  # Run Underscore.js in noConflict mode, returning the '_' variable to its
+  # previous owner. Returns a reference to the Underscore object.
+  _.noConflict = function() {
+    root._ = previousUnderscore;
+    return this;
+  };
+
+  # Keep the identity function around for default iterators.
+  _.identity = function(value) {
+    return value;
+  };
+
+  # Break out of the middle of an iteration.
+  _.breakLoop = function() {
+    throw breaker;
+  };
+
+  # Generate a unique integer id (unique within the entire client session).
+  # Useful for temporary DOM ids.
+  var idCounter = 0;
+  _.uniqueId = function(prefix) {
+    var id = idCounter++;
+    return prefix ? prefix + id : id;
+  };
+
+  # JavaScript templating a-la ERB, pilfered from John Resig's
+  # "Secrets of the JavaScript Ninja", page 83.
+  _.template = function(str, data) {
+    var fn = new Function('obj',
+      'var p=[],print=function(){p.push.apply(p,arguments);};' +
+      'with(obj){p.push(\'' +
+      str
+        .replace(/[\r\t\n]/g, " ")
+        .split("<%").join("\t")
+        .replace(/((^|%>)[^\t]*)'/g, "$1\r")
+        .replace(/\t=(.*?)%>/g, "',$1,'")
+        .split("\t").join("');")
+        .split("%>").join("p.push('")
+        .split("\r").join("\\'")
+    + "');}return p.join('');");
+    return data ? fn(data) : fn;
+  };
+
+  /*------------------------------- Aliases ----------------------------------*/
+
+  _.forEach  = _.each;
+  _.foldl    = _.inject       = _.reduce;
+  _.foldr    = _.reduceRight;
+  _.filter   = _.select;
+  _.every    = _.all;
+  _.some     = _.any;
+  _.head     = _.first;
+  _.tail     = _.rest;
+  _.methods  = _.functions;
+
+  /*------------------------ Setup the OOP Wrapper: --------------------------*/
+
+  # Helper function to continue chaining intermediate results.
+  var result = function(obj, chain) {
+    return chain ? _(obj).chain() : obj;
+  };
+
+  # Add all of the Underscore functions to the wrapper object.
+  _.each(_.functions(_), function(name) {
+    var method = _[name];
+    wrapper.prototype[name] = function() {
+      unshift.call(arguments, this._wrapped);
+      return result(method.apply(_, arguments), this._chain);
+    };
+  });
+
+  # Add all mutator Array functions to the wrapper.
+  _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
+    var method = Array.prototype[name];
+    wrapper.prototype[name] = function() {
+      method.apply(this._wrapped, arguments);
+      return result(this._wrapped, this._chain);
+    };
+  });
+
+  # Add all accessor Array functions to the wrapper.
+  _.each(['concat', 'join', 'slice'], function(name) {
+    var method = Array.prototype[name];
+    wrapper.prototype[name] = function() {
+      return result(method.apply(this._wrapped, arguments), this._chain);
+    };
+  });
+
+  # Start chaining a wrapped Underscore object.
+  wrapper.prototype.chain = function() {
+    this._chain = true;
+    return this;
+  };
+
+  # Extracts the result from a wrapped and chained object.
+  wrapper.prototype.value = function() {
+    return this._wrapped;
+  };
+
+()