creamerscript

CreamerScript

CreamerScript is a language framework on top of Coffeescript.

Overview

CreamerScript itself is really only a Compiler. That Compiler is really just a standard way of transforming code. Sweeteners are what actually do the heavy lifting.

Process

The compilation process is done in two stages. In the first stage, it runs through all registered Sweeteners and tells them to substitute any code they will later want to transform with special tokens.

Once all chunks of code are replaced with tokens, the Compiler will iterate through those tokens, find the Sweetener responsible for it and ask it to transform it to Coffeescript. It does this recursively until all tokens are replaced with the transformed code.

Rationale

This is very much a poor man's parser approach. There is no AST and is therefor not a super robust system. You need to be able to match a chunk of code with a regexp in order to use it with CreamerScript.

The substitution phase is done depth first, meaning the inner-most entities (of nested entities) are substituted first. Strings, Arrays and Objects are all substituted first. This gets rid of a lot of the headache of dealing with nested entities.

Example

class Gear
  def constructor:chainring cog:cog
    @chainring = chainring
    @cog       = cog

  def gear_inches:diameter
    (this ratio:) / diameter

  def ratio
    @chainring / (@cog to_f)


class Wheel
  def constructor:rim tire:tire chainring:chainring cog:cog
    @rim  = rim
    @tire = tire
    @gear = (Gear new:chainring cog:cog)

  def diameter
    @rim + (@tire size)

  def gear_inches
    diameter = (this diameter:)
    (@gear gear_inches:diameter)

Usage

From the command line:

$ creamer path/to/file.creamer

From Ruby:

require "creamerscript"
compiler = Creamerscript::Compiler.new("(person say:word)")
compiler.compile
# => "person.say(word)"