Class: BreadCalculator::Parser

Inherits:

Object

• Object
• BreadCalculator::Parser

Defined in:

lib/bread_calculator.rb

Overview

This class converts a nearly free-form text file to a Recipe

Instance Method Summary

• #initialize ⇒ Parser constructor

  Create a new parser for Recipe.

• #parse(input) ⇒ Object

  Parse text from IO object input.

Constructor Details

#initialize ⇒ Parser

Create a new parser for Recipe

# File 'lib/bread_calculator.rb', line 375

def initialize
  @i = 0
  @args = @steps = []
  @steps[0] = BreadCalculator::Step.new

  @in_prelude = true
  @prelude = ''
  @metadata = Hash.new(nil)
end

Instance Method Details

#parse(input) ⇒ Object

Parse text from IO object input. It is the caller’s responsibility to open and close the input correctly.

text recipes consist of a metadata prelude followed by steps.

In prelude lines, anything before a colon is considered to be the name of a metadata field; anything after the colon is a value to populate. Lines without colons are continuations of the ‘notes’ field. I suggest having at least a ‘name’ field.

A line starting with a hyphen ends the prelude and starts the first step.

Each step is delimited by one or more blank lines.

Any line in a step starting with a space or a blank is an ingredient, consisting of quantity, units, and the ingredient itself.

A brief sample:

name: imaginary bread
notes: This is a silly fake bread recipe
makes: 1 bad loaf
This line will become part of the notes
---------------------
Mix:
  500 g flour
  300 g water

Bake at 375°

# File 'lib/bread_calculator.rb', line 417

def parse input

  while line = input.gets
    new_step              && next if line =~ /(^-)|(^\s*$)/
    preprocess_meta(line) && next if @in_prelude

    @args << preprocess_step(line.chomp)
  end   

  close_step
  # because we made a spurious one to begin with
  @steps.shift
  Recipe.new @metadata, @steps
end