Class: Lisp::Format::Directives::BeginIteration

Inherits:
Directive show all
Defined in:
lib/carat/lisp-format.rb

Overview

Represents the ~{ (Begin iteration) directive. A given set of directives is used iteratively over a set of arguments (depends on the modifiers specified) a given number of times, or until it runs out of arguments.

Instance Attribute Summary

Attributes inherited from Directive

#pos

Instance Method Summary collapse

Methods inherited from Directive

#join

Constructor Details

#initialize(params, modifiers, top, pos) ⇒ BeginIteration

Create and set up some private variables



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# File 'lib/carat/lisp-format.rb', line 1617

def initialize(params, modifiers, top, pos)
  super params, modifiers, top, pos
  @directives = []
end

Instance Method Details

#connect(directives) ⇒ Object

Connect a set of directives to this iteration directive.



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# File 'lib/carat/lisp-format.rb', line 1657

def connect(directives)
  directives.pop
  @directives = directives
end

#execute(state) ⇒ Object

Iteratively run the contained directives using sets of arguments depending upon what modifiers where given. The full form is

~n:@{...~}

with the following interpretations

n

maximum number of times the iteration should be performed,

no modifiers

the iteration reads an argument, which must be an Array, and uses it as the arguments to the contained directives,

:

the iteration reads an argument, which must be an Array containing sub-arrays, and uses the sub-arrays as the arguments to the contained directives, moving to the next one on each iteration,

@

the iteration uses the rest of the arguments as arguments to the contained directives,

:@

the iteration uses the rest of the arguments, which must be Arrays, using each Array as the set of arguments to the contained directives.



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# File 'lib/carat/lisp-format.rb', line 1642

def execute(state)
  n = param(0, state, nil)
  return if not n.nil? and n == 0
  if colon_mod? and at_mod?
    execute_sets(n, state, false)
  elsif at_mod?
    execute_args(n, nil, state, false)
  elsif colon_mod?
    execute_sets(n, state, true)
  else
    execute_args(n, state.next_arg, state, true)
  end
end