Class: BisonParser

Inherits:
Object
  • Object
show all
Includes:
Base
Defined in:
lib/bison_parser.rb,
lib/bison_parser/base.rb,
lib/bison_parser/actions.rb,
ext/bison_parser/bison_parser.c

Defined Under Namespace

Modules: Base, Tokens Classes: Actions, Error

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Base

#begin_token, #error, #initialize, #peak, #read

Instance Attribute Details

#col ⇒ Object

Returns the value of attribute col.



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# File 'lib/bison_parser/base.rb', line 3

def col
  @col
end

#io ⇒ Object (readonly)

Returns the value of attribute io.



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# File 'lib/bison_parser/base.rb', line 2

def io
  @io
end

#lex_value ⇒ Object

Returns the value of attribute lex_value.



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# File 'lib/bison_parser/base.rb', line 3

def lex_value
  @lex_value
end

#result ⇒ Object

Returns the value of attribute result.



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# File 'lib/bison_parser/base.rb', line 4

def result
  @result
end

#row ⇒ Object

Returns the value of attribute row.



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# File 'lib/bison_parser/base.rb', line 3

def row
  @row
end

#section ⇒ Object

Returns the value of attribute section.



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# File 'lib/bison_parser.rb', line 3

def section
  @section
end

#source ⇒ Object

Returns the value of attribute source.



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# File 'lib/bison_parser/base.rb', line 4

def source
  @source
end

#token_col ⇒ Object

Returns the value of attribute token_col.



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# File 'lib/bison_parser/base.rb', line 3

def token_col
  @token_col
end

#token_row ⇒ Object

Returns the value of attribute token_row.



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# File 'lib/bison_parser/base.rb', line 3

def token_row
  @token_row
end

Instance Method Details

#lex ⇒ Object 



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# File 'lib/bison_parser.rb', line 5

def lex
  x = real_lex
  Tokens.constants.each do |const|
    if Tokens.const_get(const) == x
      warn "Lex'd #{const}\t: #{lex_value.inspect}" if ENV['DEBUG_GRAMMAR']
      return x
    end
  end

  warn "Lex'd #{x.inspect}" if ENV['DEBUG_GRAMMAR']

  x
end

#parse ⇒ Object 



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# File 'ext/bison_parser/bison_parser.c', line 1786

static VALUE bison_parser_parse(VALUE);

#real_lex ⇒ Object 



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# File 'lib/bison_parser.rb', line 19

def real_lex
  self.section ||= 0
  self.lex_value = nil

  if section == 2
    self.lex_value = io.read
    self.section += 2
    return Tokens::ACTIONS
  end

  # skip space
  while true
    while (c = self.read) && c =~ /\s/
    end

    if c == '#'
      while (char = self.read) && char != "\n"
      end
    else
      break
    end
  end

  return nil unless c

  case c
  when ':'
    return Tokens::COLON
  when ';'
    return Tokens::SEMICOLON
  when '|'
    return Tokens::PIPE
  when '%'
    if self.peak == '%'
      self.read
      self.section += 1
      return Tokens::DOUBLE_HASH
    end
    return Tokens::HASH
  when '['
    return Tokens::LBRACK
  when ']'
    return Tokens::RBRACK
  when '{'
    nesting = 1
    action = ''
    while (c = self.read) && nesting > 0
      nesting += 1 if c == '{'
      nesting -= 1 if c == '}'
      action << c unless nesting.zero?
    end
    self.lex_value = action
    return Tokens::ACTIONS
  when '0'..'9'
    number = c
    while (c = self.peak) && ('0'..'9').include?(c)
      number << self.read
    end
    self.lex_value = number.to_i
    return Tokens::NUMBER
  when '"'
    string = ''
    while (c = self.read) && c != '"'
      string << c
    end
    self.lex_value = string
    return Tokens::STRING
  when "'"
    string = ''
    while (c = self.read) && c != "'"
      string << c
    end
    self.lex_value = string
    return Tokens::STRING
  end

  if c =~ /\w/
    string = c
    while (c = self.peak) && c =~ /\w/
      self.read
      string << c
    end

    if section.zero? && string == 'token'
      return Tokens::KW_TOKEN
    elsif section.zero? && string == 'left'
      return Tokens::KW_LEFT
    elsif section.zero? && string == 'right'
      return Tokens::KW_RIGHT
    else
      self.lex_value = string
      return Tokens::IDENTIFIER
    end
  end

  warn "Yielding literal #{c.inspect}"

  return c.ord
end