Class: Kwartz::PresentationLogicParser

Inherits:
Object
  • Object
show all
Includes:
Assertion, CharacterType
Defined in:
lib/kwartz/parser.rb

Overview

.[abstract] parser class for presentation logic

Direct Known Subclasses

CssStyleParser, RubyStyleParser

Constant Summary collapse

PLOGIC_KEYWORDS = 
table
ESCAPE_FLAG_TABLE = 
table
@@class_table = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Assertion

assert

Methods included from CharacterType

#is_alpha, #is_digit, #is_identchar, #is_whitespace

Constructor Details

#initialize(properties = {}) ⇒ PresentationLogicParser

Returns a new instance of PresentationLogicParser.



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# File 'lib/kwartz/parser.rb', line 65

def initialize(properties={})
  @properties = properties
end

Instance Attribute Details

#column ⇒ Object (readonly)

Returns the value of attribute column.



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# File 'lib/kwartz/parser.rb', line 88

def column
  @column
end

#error ⇒ Object (readonly)

Returns the value of attribute error.



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# File 'lib/kwartz/parser.rb', line 88

def error
  @error
end

#linenum ⇒ Object (readonly)

Returns the value of attribute linenum.



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# File 'lib/kwartz/parser.rb', line 88

def linenum
  @linenum
end

#pos ⇒ Object (readonly)

Returns the value of attribute pos.



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# File 'lib/kwartz/parser.rb', line 88

def pos
  @pos
end

#token ⇒ Object (readonly)

Returns the value of attribute token.



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# File 'lib/kwartz/parser.rb', line 88

def token
  @token
end

#value ⇒ Object (readonly)

Returns the value of attribute value.



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# File 'lib/kwartz/parser.rb', line 88

def value
  @value
end

Class Method Details

.get_class(css) ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 376

def self.get_class(css)
  return @@class_table[css]
end

.register_class(css, klass) ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 371

def self.register_class(css, klass)
  @@class_table[css] = klass
end

Instance Method Details

#_parse_block ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 348

def _parse_block
  scan()
  unless @token == :'{'
    raise parse_error("'#{@value}': '{' expected.")
  end
  start_linenum, start_column = @linenum, @column
  t = scan_block(true)
  if t == :error
    if @error == :block_unclosed
      raise parse_error("'{': not closed by '}'.", start_linenum, start_column)
    else
      assert("@error=#{@error}")
    end
  end
  @value.sub!(/\A[ \t]*\n/, '')
  @value.sub!(/^[ \t]+\z/, '')
  return @value
end

#escape?(value) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/kwartz/parser.rb', line 113

def escape?(value)
  return ESCAPE_FLAG_TABLE[value]
end

#getch ⇒ Object

scanner



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# File 'lib/kwartz/parser.rb', line 120

def getch
  return @ch = nil if @pos >= @max_pos
  if @ch == ?\n
    @linenum += 1
    @column = 0
  end
  @pos += 1
  @column += 1
  @ch = @input[@pos]
  return @ch
end

#keywords(keyword) ⇒ Object

.[abstract] detect parser-specific keywords

return symbol if keyword is token, else return nil



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# File 'lib/kwartz/parser.rb', line 225

def keywords(keyword)
  not_implemented
end

#parse(input, filename = '') ⇒ Object

.[abstract] parse input string and return list of ElementRuleset



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# File 'lib/kwartz/parser.rb', line 343

def parse(input, filename='')
  not_implemented
end

#parse_error(message, linenum = @linenum, column = @column) ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 337

def parse_error(message, linenum=@linenum, column=@column)
  return ParseError.new(message, @filename, linenum, column)
end

#scan ⇒ Object

scan token



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# File 'lib/kwartz/parser.rb', line 231

def scan
  ## skip whitespaces
  c = @ch
  while is_whitespace(c)
    c = getch()
  end

  ## return nil when EOF
  if c == nil
    @value = nil
    return @token = nil
  end

  ## scan hook
  ret = scan_hook()    # scan_hook() is overrided in subclass
  return ret if ret != false

  ## keyword or identifer
  if is_identchar(c)
    scan_ident()
    @token = keywords(@value) || PLOGIC_KEYWORDS[@value] || :ident
    return @token
  end

  ## "string"
  if c == ?"
    return scan_string_dquoted()
  end

  ## 'string'
  if c == ?'
    return scan_string_quoted()
  end

  ## '{'
  if c == ?{
    @value = "{"
    getch()
    return @token = :'{'
  end

  ## '}'
  if c == ?}
    @value = "}"
    getch()
    return @token = :'}'
  end

  ## ','
  if c == ?,
    @value = ","
    getch()
    return @token = :','
  end

  ##
  @value = c.chr
  @error = :invalid_char
  return @token = :error
end

#scan_block(skip_open_curly = false) ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 293

def scan_block(skip_open_curly=false)
  unless skip_open_curly
    token = scan()
    unless token == ?{
      @error = :block_notfound
      return @token = :error
    end
  end
  start_pos = @pos
  count = 1
  while (c = getch()) != nil
    if c == ?{
      count += 1
    elsif c == ?}
      count -= 1
      break if count == 0
    end
  end
  unless c
    @error = :block_unclosed
    return @token = :error
  end
  assert unless c == ?}
  @value = @input[start_pos, @pos - start_pos]
  @token = :block
  getch()
  return @value
end

#scan_hook ⇒ Object

called from scan(), return false when not hooked



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# File 'lib/kwartz/parser.rb', line 217

def scan_hook
  #not_implemented
end

#scan_ident ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 133

def scan_ident
  ## identifer
  if is_identchar(@ch)
    sb = @ch.chr
    while (c = getch()) && is_identchar(c)
      sb << c.chr
    end
    @value = sb
    return @token = :ident
  end
  return nil
end

#scan_line ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 323

def scan_line
  sb = @ch.chr
  while (c = getch()) != nil && c != ?\n
    sb << c.chr
  end
  sb.chop if sb[-1] == ?\r
  getch()
  return sb
end

#scan_string ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 178

def scan_string
  if @ch == ?'
    return scan_string_quoted()
  elsif @ch == ?"
    return scan_string_dquoted()
  else
    return nil
  end
end

#scan_string_dquoted ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 147

def scan_string_dquoted
  return nil unless @ch == ?"
  s = ''
  while (c = getch()) && c != ?"
    if c == ?\\
      c = getch()
      break unless c
      case c
      when ?n  ;  s << "\n"
      when ?t  ;  s << "\t"
      when ?r  ;  s << "\r"
      when ?b  ;  s << "\b"
      when ?\\ ;  s << "\\"
      when ?"  ;  s << '"'
      else     ;  s << c.chr
      end
    else
      s << c.chr
    end
  end
  unless c
    @error = :string_unclosed
    return @token = :error
  end
  assert unless c == ?"
  getch()
  @value = s
  return @token = :string
end

#scan_string_quoted ⇒ Object 



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# File 'lib/kwartz/parser.rb', line 189

def scan_string_quoted
  return nil unless @ch == ?'
  s = ''
  while (c = getch()) && c != ?'
    if c == ?\\
      c = getch()
      break unless c
      case c
      when ?\\ ;  s << "\\"
      when ?'  ;  s << "'"
      else     ;  s << "\\" << c.chr
      end
    else
      s << c.chr
    end
  end
  unless c
    @error = :string_unclosed
    return @token = :error
  end
  assert unless c == ?'
  getch()
  @value = s
  return @token = :string
end