Class: YaccShave::Parser

Inherits:
Racc::Parser
  • Object
show all
Defined in:
lib/yacc_shave/parser/lexer.rb,
lib/yacc_shave/parser/parser.rb

Defined Under Namespace

Classes: ScanError

Constant Summary collapse

Racc_arg = 
[
racc_action_table,
racc_action_check,
racc_action_default,
racc_action_pointer,
racc_goto_table,
racc_goto_check,
racc_goto_default,
racc_goto_pointer,
racc_nt_base,
racc_reduce_table,
racc_token_table,
racc_shift_n,
racc_reduce_n,
racc_use_result_var ]
Racc_token_to_s_table = 
[
"$end",
"error",
"INTEGER",
"ADD",
"NEWLINE",
"IDENTIFIER",
"ASSIGN",
"LCBRA",
"RCBRA",
"COMMA",
"DOT",
"SUBTRACT",
"$start",
"root",
"program",
"expressions",
"number",
"variable_access",
"variable_assignment",
"expression",
"elements",
"binary_operation",
"terminator" ]
Racc_debug_parser = 
false

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/yacc_shave/parser/lexer.rb', line 14

def filename
  @filename
end

#lineno ⇒ Object (readonly)

Returns the value of attribute lineno.



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# File 'lib/yacc_shave/parser/lexer.rb', line 13

def lineno
  @lineno
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/yacc_shave/parser/lexer.rb', line 15

def state
  @state
end

Instance Method Details

#_next_token ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 54

def _next_token
  text = @ss.peek(1)
  @lineno  +=  1  if text == "\n"
  token = case @state
  when nil
    case
    when (text = @ss.scan(/\d+/))
       action { [:INTEGER, text.to_i] }

    when (text = @ss.scan(/[a-z_?!]+/))
       action { [:IDENTIFIER, text]}

    when (text = @ss.scan(/\+/))
       action { [:ADD, text] }

    when (text = @ss.scan(/\=/))
       action { [:ASSIGN, text]}

    when (text = @ss.scan(/\{/))
       action { [:LCBRA, text]}

    when (text = @ss.scan(/\}/))
       action { [:RCBRA, text]}

    when (text = @ss.scan(/\,/))
       action { [:COMMA, text]}

    when (text = @ss.scan(/\./))
       action { [:DOT, text]}

    when (text = @ss.scan(/\n/))
       action { [:NEWLINE, text]}

    when (text = @ss.scan(/./))
      ;

    else
      text = @ss.string[@ss.pos .. -1]
      raise  ScanError, "can not match: '" + text + "'"
    end  # if

  else
    raise  ScanError, "undefined state: '" + state.to_s + "'"
  end  # case state
  token
end

#_reduce_none(val, _values) ⇒ Object

reduce 16 omitted



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# File 'lib/yacc_shave/parser/parser.rb', line 226

def _reduce_none(val, _values)
  val[0]
end

#action ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 23

def action
  yield
end

#load_file(filename) ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 33

def load_file( filename )
  @filename = filename
  open(filename, "r") do |f|
    scan_setup(f.read)
  end
end

#next_token ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 46

def next_token
  return if @ss.eos?
  
  # skips empty actions
  until token = _next_token or @ss.eos?; end
  token
end

#scan_file(filename) ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 40

def scan_file( filename )
  load_file(filename)
  do_parse
end

#scan_setup(str) ⇒ Object 



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# File 'lib/yacc_shave/parser/lexer.rb', line 17

def scan_setup(str)
  @ss = StringScanner.new(str)
  @lineno =  1
  @state  = nil
end

#scan_str(str) ⇒ Object Also known as: scan 



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# File 'lib/yacc_shave/parser/lexer.rb', line 27

def scan_str(str)
  scan_setup(str)
  do_parse
end

#tokenize(code) ⇒ Object

def _next_token



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# File 'lib/yacc_shave/parser/lexer.rb', line 101

def tokenize(code)
  scan_setup(code)
  tokens = []
  while token = next_token
    tokens << token
  end
  tokens
end