Class: Citrus::Terminal

Inherits:
Object show all
Includes:
Rule
Defined in:
lib/citrus.rb

Overview

A Terminal is a Rule that matches directly on the input stream and may not contain any other rule. Terminals are essentially wrappers for regular expressions. As such, the Citrus notation is identical to Ruby’s regular expression notation, e.g.:

/expr/

Character classes and the dot symbol may also be used in Citrus notation for compatibility with other parsing expression implementations, e.g.:

[a-zA-Z]
.

Character classes have the same semantics as character classes inside Ruby regular expressions. The dot matches any character, including newlines.

Direct Known Subclasses

StringTerminal

Instance Attribute Summary collapse

Attributes included from Rule

#extension, #grammar, #label, #name

Instance Method Summary collapse

Methods included from Rule

#===, #default_options, #elide?, #extend_match, for, #inspect, #needs_paren?, #parse, #test, #to_embedded_s, #to_s

Constructor Details

#initialize(regexp = /^/) ⇒ Terminal

Returns a new instance of Terminal.



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# File 'lib/citrus.rb', line 881

def initialize(regexp=/^/)
  @regexp = regexp
end

Instance Attribute Details

#regexp ⇒ Object (readonly)

The actual Regexp object this rule uses to match.



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# File 'lib/citrus.rb', line 886

def regexp
  @regexp
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/citrus.rb', line 906

def ==(other)
  case other
  when Regexp
    @regexp == other
  else
    super
  end
end

#case_sensitive? ⇒ Boolean

Returns true if this rule is case sensitive.

Returns:

  • (Boolean) 


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# File 'lib/citrus.rb', line 902

def case_sensitive?
  !@regexp.casefold?
end

#exec(input, events = []) ⇒ Object

Returns an array of events for this rule on the given input.



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# File 'lib/citrus.rb', line 889

def exec(input, events=[])
  match = input.scan(@regexp)

  if match
    events << self
    events << CLOSE
    events << match.length
  end

  events
end

#terminal? ⇒ Boolean

Returns true if this rule is a Terminal.

Returns:

  • (Boolean) 


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# File 'lib/citrus.rb', line 918

def terminal? # :nodoc:
  true
end

#to_citrus ⇒ Object

Returns the Citrus notation of this rule as a string.



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# File 'lib/citrus.rb', line 923

def to_citrus # :nodoc:
  @regexp.inspect
end