Class: RParsec::OperatorTable

Inherits:
Object
  • Object
show all
Defined in:
lib/rparsec/expressions.rb

Overview

to register operators.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#operators ⇒ Object (readonly)

operators attribute is used internally. Do not access it.



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# File 'lib/rparsec/expressions.rb', line 16

def operators
  @operators
end

Class Method Details

.new ⇒ Object

To create an OperatorTable instance. If a block is given, it is invoked to do post-instantiation. For example:

OperatorTable.new do |tbl|

tbl.infixl(char(?+) >> Plus, 10)
tbl.infixl(char(?-) >> Minus, 10)
tbl.infixl(char(?*) >> Mul, 20)
tbl.infixl(char(?/) >> Div, 20)
tbl.prefix(char(?-) >> Neg, 50)

end



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# File 'lib/rparsec/expressions.rb', line 38

def self.new
  this = allocate
  this.reinit
  if block_given?
    yield this
  end
  this
end

Instance Method Details

#infixl(op, precedence) ⇒ Object

Defines a left associative infix operator that returns a binary Proc object with a precedence associated. Returns self.



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# File 'lib/rparsec/expressions.rb', line 67

def infixl(op, precedence)
  add(:infixl, op, precedence)
end

#infixn(op, precedence) ⇒ Object

Defines a non-associative infix operator that returns a binary Proc object with a precedence associated. Returns self.



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# File 'lib/rparsec/expressions.rb', line 83

def infixn(op, precedence)
  add(:infixn, op, precedence)
end

#infixr(op, precedence) ⇒ Object

Defines a right associative infix operator that returns a binary Proc object with a precedence associated. Returns self.



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# File 'lib/rparsec/expressions.rb', line 75

def infixr(op, precedence)
  add(:infixr, op, precedence)
end

#postfix(op, precedence) ⇒ Object

Defines a postfix operator that returns a unary Proc object with a precedence associated. Returns self.



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# File 'lib/rparsec/expressions.rb', line 59

def postfix(op, precedence)
  add(:postfix, op, precedence)
end

#prefix(op, precedence) ⇒ Object

Defines a prefix operator that returns a unary Proc object with a precedence associated. Returns self.



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# File 'lib/rparsec/expressions.rb', line 51

def prefix(op, precedence)
  add(:prefix, op, precedence)
end

#reinit ⇒ Object

Re-initialize the operator table. Internal use only.



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# File 'lib/rparsec/expressions.rb', line 21

def reinit
  @operators = []
end