Class: Calyx::Syntax::Unique

Inherits:

Object

• Object
• Calyx::Syntax::Unique

Defined in:

lib/calyx/syntax/unique.rb

Overview

A type of production rule representing a unique substitution which only returns values that have not previously been selected. The probability that a given rule will be selected increases as more selections are made and the list grows smaller.

Constant Summary

SIGIL =

'$'.freeze

Instance Method Summary

• #evaluate(options) ⇒ Array

  Evaluate the unique rule, using the registry to handle the expansion and keep track of previous selections.

• #initialize(symbol, registry) ⇒ Unique constructor

  Construct a unique rule, given the symbol to lookup and the registry to look it up in.

Constructor Details

#initialize(symbol, registry) ⇒ Unique

Construct a unique rule, given the symbol to lookup and the registry to look it up in.

Parameters:

• symbol (Symbol)
• registry (Calyx::Registry)

# File 'lib/calyx/syntax/unique.rb', line 15

def initialize(symbol, registry)
  @symbol = symbol.slice(1, symbol.length-1).to_sym
  @registry = registry
end

Instance Method Details

#evaluate(options) ⇒ Array

Evaluate the unique rule, using the registry to handle the expansion and keep track of previous selections.

Parameters:

• options (Calyx::Options)

Returns:

• (Array)

# File 'lib/calyx/syntax/unique.rb', line 25

def evaluate(options)
  [@symbol, @registry.unique_expansion(@symbol)]
end