Class: Fabulator::Grammar::Expr::Rule
- Inherits:
-
Object
- Object
- Fabulator::Grammar::Expr::Rule
- Defined in:
- lib/fabulator/grammar/expr/rule.rb
Instance Attribute Summary collapse
-
#name ⇒ Object
Returns the value of attribute name.
Instance Method Summary collapse
- #add_alternative(a) ⇒ Object
-
#initialize ⇒ Rule
constructor
A new instance of Rule.
- #parse(s) ⇒ Object
Constructor Details
#initialize ⇒ Rule
Returns a new instance of Rule.
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# File 'lib/fabulator/grammar/expr/rule.rb', line 7 def initialize @alternatives = [ ] end |
Instance Attribute Details
#name ⇒ Object
Returns the value of attribute name.
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# File 'lib/fabulator/grammar/expr/rule.rb', line 5 def name @name end |
Instance Method Details
#add_alternative(a) ⇒ Object
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# File 'lib/fabulator/grammar/expr/rule.rb', line 11 def add_alternative(a) @alternatives << a end |
#parse(s) ⇒ Object
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# File 'lib/fabulator/grammar/expr/rule.rb', line 15 def parse(s) if s.anchored @alternatives.each do |alternative| ret = s.attempt { |cursor| cursor.anchored = true alternative.parse(cursor) } return ret unless ret.nil? end else while !s.eof @alternatives.each do |alternative| ret = s.attempt { |cursor| cursor.anchored = true alternative.parse(cursor) } return ret unless ret.nil? end s.advance_position(1) end end return nil end |