Class: FormatLine

Inherits:
StringParser show all
Defined in:
lib/formatline.rb

Overview

Class FormatLine handles the parsing of comments, dot commands, and simple formatting characters.

Constant Summary collapse

SimpleFormats = 
{}
Null = 
""
Space = 
" "
Alpha = 
/[A-Za-z]/
AlNum = 
/[A-Za-z0-9_]/
LF = 
"\n"
LBrack = 
"["
Blank = 
[" ", nil, "\n"]
Punc = 
[")", ",", ".", " ", "\n"]
NoAlpha = 
/[^A-Za-z0-9_]/
NoAlphaDot = 
/[^.A-Za-z0-9_]/
Param = 
["]", "\n", nil]
Escape =

not an ESC char

"\\"
Syms = 
{ "*" => :b, "_" => :i, "`" => :t, "~" => :s }

Instance Attribute Summary collapse

Attributes inherited from StringParser

#eos, #i, #len, #line

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from StringParser

#eos?, #grab, #next!, #peek, #prev, #skip_spaces, #ungrab

Constructor Details

#initialize(line) ⇒ FormatLine

Returns a new instance of FormatLine.



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# File 'lib/formatline.rb', line 30

def initialize(line)
  super
  @token = Null.dup
  @tokenlist = []
end

Instance Attribute Details

#out ⇒ Object (readonly)

Returns the value of attribute out.



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# File 'lib/formatline.rb', line 27

def out
  @out
end

#tokenlist ⇒ Object (readonly)

Returns the value of attribute tokenlist.



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# File 'lib/formatline.rb', line 28

def tokenlist
  @tokenlist
end

Class Method Details

.parse!(line) ⇒ Object 



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# File 'lib/formatline.rb', line 36

def self.parse!(line)
  return nil if line.nil?
  x = self.new(line.chomp)
  t = x.tokenize
# TTY.puts "tokens = \n#{t.inspect}\n "
  x.evaluate
end

.var_func_parse(str) ⇒ Object 



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# File 'lib/formatline.rb', line 75

def self.var_func_parse(str)
  return nil if str.nil?
  x = self.new(str.chomp)
  char = x.peek
  loop do
    char = x.grab
    break if char == LF || char == nil
    x.handle_escaping if char == Escape
    x.dollar if char == "$"
    x.add char
  end
  x.add_token(:str)
  result = x.evaluate
  result
end

Instance Method Details

#add(str) ⇒ Object 



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# File 'lib/formatline.rb', line 176

def add(str)
  @token << str unless str.nil?
end

#add_token(kind, token = @token) ⇒ Object 



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# File 'lib/formatline.rb', line 180

def add_token(kind, token = @token)
  return if token.nil?
  @tokenlist << [kind, token] unless token.empty?
  @token = Null.dup
end

#collect!(sym, terminators, bracketed = nil) ⇒ Object 



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# File 'lib/formatline.rb', line 330

def collect!(sym, terminators, bracketed=nil)
  return collect_bracketed(sym, terminators) if bracketed

  str = Null.dup   # next is not " ","*","["
  grab   # ZZZ
  loop do
    case
      when peek.nil?
        return str
      when peek == Escape
        str << escaped
        next
      when terminate?(terminators, peek)
        break 
    else
      str << peek    # not a terminator
    end
    grab
  end
  ungrab
  add str
  str
rescue => err
  STDERR.puts "ERR = #{err}\n#{err.backtrace}"
  STDERR.puts "=== str = #{str.inspect}"
end

#collect_bracketed(sym, terminators) ⇒ Object 



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# File 'lib/formatline.rb', line 298

def collect_bracketed(sym, terminators)
  str = Null.dup   # next is not " ","*","["
  grab   # ZZZ
  loop do
    if peek == Escape
      grab
      str << grab
      next
    end
    if terminate?(terminators, peek)
      break 
    end
    str << peek    # not a terminator
    grab
  end

  if peek == "]" # skip right bracket
    grab 
  end
  add str
  str
rescue => err
  STDERR.puts "ERR = #{err}\n#{err.backtrace}"
  STDERR.puts "=== str = #{str.inspect}"
end

#dollar ⇒ Object 



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# File 'lib/formatline.rb', line 210

def dollar
  grab
  case peek
    when LF;  add "$";  add_token :str
    when " "; add "$ "; add_token :str
    when nil; add "$";  add_token :str
    when "$"; double_dollar
#     when "."; dollar_dot
    when /[A-Za-z]/
     add_token :str
      var = peek + grab_alpha_dot
      add_token(:var, var)
  else 
    add "$" + peek
    add_token(:string)
  end
end

#double_dollar ⇒ Object 



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# File 'lib/formatline.rb', line 228

def double_dollar
  case next!
    when Space; add_token :string, "$$ "; grab; return
    when LF, nil; add "$$"; add_token :str
    when Alpha
      add_token(:str, @token)
      func = grab_alpha
      add_token(:func, func)
      case next!
        when ":"; param = grab_colon_param; add_token(:colon, param)
        when "["; param = grab_func_param; add_token(:brackets, param)
      end
    else
      grab; add_token :str, "$$" + peek; return
  end
end

#double_marker(char) ⇒ Object 



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# File 'lib/formatline.rb', line 276

def double_marker(char)
  sym = Syms[char]
  kind = sym
  case next!   # first char after **
    when Space, LF, nil
      pre, post = SimpleFormats[sym]
      add_token kind
    else
      str = collect!(sym, Punc)
      add_token kind, str
      grab 
  end
end

#embed(sym, str) ⇒ Object 



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# File 'lib/formatline.rb', line 96

def embed(sym, str)
  pre, post = SimpleFormats[sym]
  pre + str + post
end

#embedded? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formatline.rb', line 374

def embedded?
  ! (['"', "'", " ", nil].include? prev)
end

#escaped ⇒ Object 



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# File 'lib/formatline.rb', line 324

def escaped
  grab
  ch = grab
  ch
end

#evaluate(tokens = @tokenlist) ⇒ Object 



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# File 'lib/formatline.rb', line 101

def evaluate(tokens = @tokenlist)
  @out = ""
  return "" if tokens.empty?
  gen = tokens.each
  token = gen.next
  loop do 
    break if token.nil? 
    sym, val = *token
    case sym
      when :str
        @out << val unless val == "\n"   # BUG
      when :var
        @out << varsub(val)
      when :func 
        param = nil
        arg = gen.peek
        if [:colon, :brackets].include? arg[0] 
          arg = gen.next  # for real
          param = arg[1]
          param = Livetext.interpolate(param)
        end
        @out << funcall(val, param)
      when :b, :i, :t, :s
        val = Livetext.interpolate(val)
        @out << embed(sym, val)
    else
      add_token :str
    end
    token = gen.next
  end
  @out
end

#funcall(name, param) ⇒ Object 



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# File 'lib/formatline.rb', line 357

def funcall(name, param)
  err = "[Error evaluating $$#{name}(#{param})]"
  result = 
    if self.respond_to?("func_" + name.to_s)
      self.send("func_" + name.to_s, param)
    else
      fobj = ::Livetext::Functions.new
      fobj.send(name, param) rescue err
    end
  result
end

#grab_alpha ⇒ Object 



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# File 'lib/formatline.rb', line 186

def grab_alpha
  str = Null.dup
  grab
  loop do
    break if eos?
    str << peek
    break if terminate?(NoAlpha, next!)
    grab
  end
  str
end

#grab_alpha_dot ⇒ Object 



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# File 'lib/formatline.rb', line 198

def grab_alpha_dot
  str = Null.dup
  grab
  loop do
    break if peek.nil?   # eos?
    str << peek
    break if terminate?(NoAlphaDot, next!)
    grab
  end
  str
end

#grab_colon_param ⇒ Object 



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# File 'lib/formatline.rb', line 134

def grab_colon_param
  grab  # grab :
  param = ""
  loop do 
    case next!
      when Escape
        grab
        param << next!
        grab
      when Space, LF, nil; break
    else
      param << next!
      grab
    end
  end

  param = nil if param.empty?
  param
end

#grab_func_param ⇒ Object 



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# File 'lib/formatline.rb', line 154

def grab_func_param
  grab # [
  param = ""
  loop do 
    case next!
      when Escape
        grab
        param << next!
        grab
      when "]", LF, nil; break
    else
      param << next!
      grab
    end
  end

  add peek
  grab
  param = nil if param.empty?
  param
end

#handle_escaping ⇒ Object 



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# File 'lib/formatline.rb', line 91

def handle_escaping
  grab
  add grab
end

#long_marker(char) ⇒ Object 



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# File 'lib/formatline.rb', line 290

def long_marker(char)
  sym = Syms[char]
  # grab  # skip left bracket
  kind = sym  # "param_#{sym}".to_sym
  arg = collect!(sym, Param, true)
  add_token kind, arg
end

#marker(char) ⇒ Object

def dollar_dot add_token :ddot, @line end



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# File 'lib/formatline.rb', line 249

def marker(char)
  add_token :str
  sym = Syms[char]
  if embedded?
#     add char    # ??? add_token "*", :string
    return 
  end

  grab
  case peek
    when Space
      add char + " "
      add_token :str
      grab
    when LF, nil
      add char
      add_token :str
    when char;   double_marker(char)
    when LBrack; long_marker(char)
  else
    str = peek + collect!(sym, Blank)
    add str
    add_token sym, str
    grab
  end
end

#terminate?(terminators, ch) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formatline.rb', line 67

def terminate?(terminators, ch)
  if terminators.is_a? Regexp
    terminators === ch
  else
    terminators.include?(ch)
  end
end

#tokenize ⇒ Object 



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# File 'lib/formatline.rb', line 44

def tokenize
#   add grab
  loop do 
    case peek
      when Escape; grab; add peek; grab; add peek
      when "$"
        dollar
      when "*", "_", "`", "~"
        marker peek
        add peek
      when LF
        break if eos?  # @i >= line.size - 1
      when nil
        break
      else
        add peek
    end
    grab
  end
  add_token(:str)
  @tokenlist
end

#varsub(name) ⇒ Object 



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# File 'lib/formatline.rb', line 369

def varsub(name)
  result = Livetext::Vars[name] || "[#{name} is undefined]"
  result
end