Coco

is a CoffeeScript dialect that aims to be more radical and practical.

Why

On its way to hide JavaScript's bad parts, CoffeeScript has accumulated own quirks: horrible variable scope, awkward ranges, confusing/pointless keywords, long extension, and so on. Coco tries to amend them, entwining good parts of both.

Principles

• Respect JavaScript/ECMAScript semantics.
• Die for DRY.
• Performance over readability.
• Perl over Ruby.
• Less keywords, punctuations and runtime errors.

Differences

• Improvements
• Incompatibilities
• Side by Side Comparison

Documents

• Additions
• Annotated Source

Installation

on node.js

git clone git://github.com/satyr/coco.git && cd coco && bin/coke i

via npm

npm i coco

Changelog

0.6.7

• Fixed coffee#1715 etc.
• Trivial improvements.

0.6.6

• Added unary assignments: !! = x => x = !!x
• Made a? <<< b short for a <<< b if a?.
• Improved stack traces from directly run .co files.

0.6.5

• case/of/instanceof now works better with array slice.
• instanceof now rejects invalid right operands.

0.6.4

• Unary operators now spread into an array operand: +[a, b] => [+a, +b]
• .. now points to the constructor under class.
• coke now works from subdirectories. (coffee#1687)

0.6.3

• Added pipe operator: f! => g _ => _ = f!; g _
• Fixed identifier lexing as per ES5.
• Improved label handlings.
• Helper functions are now declared last. (coffee#1638)

0.6.2

• Added character ranges: [\a to \d] => [\a \b \c \d]
• Added named destructuring: {p, q}:o = f! => o = f!; {p, q} = o
• Numbers can no longer start with ..
• function can no longer prefix ->/~>. Use ~function to declare bound functions instead.

0.6.1

• Allowed line folding after for prepositions.
• importing onto a soaked expression is now safe.
• --json now modifies --ast or --compile.
• Fixed #81 etc.

0.6.0

Additions

• Added soak assign.
• Added <? and >? operators.
• Loops can now have else clause.
• import x is now short for this <<< x.
• , after (, [ or another , now implies void.

Changes

• Added object slice.
• Added bang call: f! => f()
• Revised clone syntax from x{} to ^x.
• Revised semiautovivification syntax from .!/.@ to .@/.@@.
• Variable interpolations no longer require braces: "(#id)" => "(" + id + ")"
• Spaced dots now close implicit calls. See coffee#1407.
• Direct calls to super now delegate this.
• extended hook is back.
• from of for is now optional, meaning from 0. tilless from is no longer allowed.

0.5.4

• while/until can now have update clause after test clause: continue while f(), g() => for (; f(); g()) {}
• that no longer triggers anaphoric conversion under unless/until.
• Disallowed a.=b = c p:~ (a, b) -> f ..., a etc.
• Fixed coffee#1416.

0.5.3

• Added do-while/until construction.
• Added $ flag to regexes. Same as .source, but more efficient.
• Suppressed implicit return on newed/setter functions.
• Sped up lexer.

0.5.2

• Added !? (inexistence) operator.
• function no longer requires parens around parameters.
• class block is now mandatory.
• Bug fixes: coffee#1352 coffee#1354

0.5.1

• a.b.c?.=d.e now works as expected.
• a[b, c] = d now works as expected.
• extras/coco.js works again on WSH.
• --output implies --compile again.

0.5.0

• Added ** operator.
• Overloaded +/-// (in addition to *) for arrays and strings.
• Revised let: let (a) ~> => let a then
• Allowed underscores within number literals.
• Major regex changes:
  • Dieted heregex: /// re /// => // re //
  • Allowed leading whitespace in normal regex literals when unambiguous.
  • No longer accepts invalid regexes.
• -> is now optional when function is used.
• case accepts comma-separated tests again.
• return/throw can now take a block.
• REPL now uses ^J to continue lines.

0.4.2

• Enabled:
  • ADI on ?.
  • ACI on ++/--
  • conditional destructuring assignments
  • colors and tab completion in REPL
• Made leading *s serve like list markers.

0.4.1

• Added string/array multiplication.
• Added label support.
• Aliased constructor as ...

0.4.0

• Added let. Unary do is back at being simple call.
• Added with.
• Added semiautovivification.
• Made :: a pure sugar for prototype, which can now directly refer to @:: under class body.
• ?. can now appear anywhere a normal dot can be used.
• ~. is changed to . ~.
• new no longer accepts splatted arguments.
• --interactive now works with --compile and --bare.
• Renamed --nodes option and .nodes method to --ast/.ast.
• Fixed the performance bug wrt long method chains.
• Quit supporting node.js 0.3.x or lower.

0.3.2

• Unrestricted ADI for identifiers beyond @ and ::.
• Expanded property shorthands beyond @foo.
• Added typeof!, which inspects the internal [[Class]] property.
• Added shebang support.
• REPL results now evaluate more intuitively.
• Disallowed whitespace mixup for indentations.

0.3.1

• debugger now works anywhere.
• Revised heregex flag syntax: ///#{x}#{y}///? -> RegExp('' + x, y);
• Removed Coco.eval.
• Made extras/coco.js work as a mini-compiler on WSH.
• Added extras/mode-coco.js, an editing mode for Ace.
• Added --json option.

0.3.0

Pure Additions

• Added backcall, a sugar to flatten nested callbacks.
• do block can now work as a pair of normal parentheses.
• Improved ACI (automatic comma insertion): f {} [] x -> f({}, [], x);
• Improved ADI (automatic dot insertion): @@0'!' -> arguments[0]['!'];
• Multiline block on the RHS of object property now works as an implicit array.
• Heregexes now support dynamic flags: /// x #{? y } /// -> RegExp('x', y);
• Enabled compound accessigns: a.+=b -> a += a.b;
• ... in array destructuring (same as ...[]) now skips items rather than sliceing them. (coffee#870)
• Compilation errors now report line numbers.
• Coco object now emits more events for use with --require.

Incompatible Changes

• => -> ~>
• &. -> ~.
• Braceless objects no longer consume property shorthands. (coffee#618)
• Indentations within non-here strings are now stripped.
• Fixed block comment syntax to good ol' /* */.
• @0 is now this[0] rather than arguments[0].

0.2.2

• is not is the new isnt.
• @'++' is now valid as a shorthand for @['++'].
• Commas between primitive values are now optional.
• coke now automatically aliases tasks.
• extras/coco.js now works as a Gecko JS Module.
• Grouped documentation suite into doc/ for portability.
• Rewrote src/optparse.co.

0.2.1

• Added numeric ranges.
• Destructuring assignments can now specify default values using logical operators. Default arguments syntax has been changed accordingly. ((a || b) -> instead of (a ||= b) ->)
• do now performs special conversions against function literals with parameters, making it work as pseudo-let and Coffee 1.0.0 compliant.
• Allowed for i from x then as a sugar for for i from 0 til x then.
• Disallowed duplicate formal arguments.
• Improved syntax-highlight in src/index.html.

0.2.0

• Version bump for Xmas, in concert with Coffee 1.0.0.
• @@ is now a shorthand for arguments.
• do can now indicate a call against indented arguments.
• and and or now close implicit calls, making you write even less parens: f x and g y or z -> f(x) && g(y) || z;
• catch's variable declaration is no longer required.
• a<[ b c ]> is now equivalent to a[\b, \c] (was a(\b, \c)).
• case now requires brackets to have multiple conditions.
• Added --nodejs option. See coffee#910.
• Renamed --stdio to --stdin.

0.1.6

• Added character/word literal: \C + \++ -> 'C' + '++';
• Retrieving multiple properties at once is now possible: a[b, c] -> [a[b], a[c]];
• Destructuring into an object's properties is now possible:
  • a[b, c] = d -> a[b] = d[0], a[c] = d[1];
  • a{b, c} = d -> a.b = d.b, a.c = d.c;
• Compound assignments can now destructure: [@a, @b] /= c -> this.a /= c[0], this.b /= c[1];

0.1.5

• Conditional control structures can now be anaphoric; that within if, while or case block now refers to the condition value.
• Decimal numbers can now have arbitrary trailing alphabets as comments. e.g. 9times, 1.5s
• Added <<</<<<< as aliases to import/import all
• non-ASCII identifiers are now allowed.

0.1.4

• . and its families can now be used with numbers and strings, instead of []. a.0.'0' compiles to a[0]['0'].
• Added syntax for cloning objects; obj{key:val} acts like a simple version of ES5 Object.create, creating a prototypal child of obj and assigning to .key with val.
• default arguments can now choose to use ||/&&.
• super under a class block now refers to the superclass.
• .coffee extension is no longer supported.

0.1.3

• Compilation now prefers single quotes.
• AST now compiles faster, roughly 1.4 times than 0.1.2.
• []/{} can now be safely used as an placeholder within array destructuring.
• Improved --nodes output.

0.1.2

• ... is now prefix.
• {0: first, (*-1): last} = array now works.
• Added --lex to the coco utility. Removed --lint.
• src/ now has doc view.

0.1.1

Release.