Class: Livetext::Expansion

Inherits:
Object show all
Defined in:
lib/livetext/expansion.rb

Constant Summary collapse

Ident = 
"[[:alpha:]]([[:alnum:]]|_)*"
Dotted = 
"#{Ident}(\\.#{Ident})*"
Func = 
"\\$\\$"
Var = 
"\\$"
Lbrack = 
"\\["
Colon = 
":"

Instance Method Summary collapse

Constructor Details

#initialize(instance) ⇒ Expansion

Returns a new instance of Expansion.



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# File 'lib/livetext/expansion.rb', line 11

def initialize(instance)
  @live = instance
end

Instance Method Details

#expand_function_calls(str) ⇒ Object 



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# File 'lib/livetext/expansion.rb', line 62

def expand_function_calls(str)
  # Assume variables already resolved
  pat1 = "(?<result>" + Func + Dotted + ")"
  colon = ":"
  lbrack = "\\["
  rbrack = "\\]"
  space_eol = "( |$)"
  prx1 = "(?<param>[^ ]+)"
  prx2 = "(?<param>.+)"
  pat2 = "(?<full_param>#{colon}#{prx1})"
  pat3 = "(?<full_param>#{lbrack}#{prx2}#{rbrack})"
  rx = Regexp.compile("#{pat1}(#{pat2}|#{pat3})?")

  buffer = ""
  loop do |i|
    case             # Var or Func or false alarm
    when str.nil?
      return buffer
    when str.empty?  # end of string
      break
    when str.slice(0..1) == "$$"   # Func?
      fmatch = rx.match(str)
      fname = fmatch["result"]  # includes $$
      param = fmatch["param"]   # may be nil
      full  = fmatch["full_param"]
      fsym  = fname[2..-1]      # no $$
#STDERR.puts "rx     = #{rx.inspect}"
#STDERR.puts "fmatch = #{fmatch.inspect}"
#STDERR.puts "fname  = #{fname.inspect}"
#STDERR.puts "param  = #{param.inspect}"
#STDERR.puts "full   = #{full.inspect}"
#STDERR.puts "fsym   = #{fsym.inspect}"
      str.sub!(fname, "")
      str.sub!(full, "") if full
      retval = funcall(fsym, param)
# puts "retval = #{retval.inspect}"
      buffer << retval
    else                        # other
      char = str.slice!(0)
      buffer << char
    end
  end
# STDERR.puts "buffer     = #{buffer.inspect}"
  buffer
end

#expand_variables(str) ⇒ Object 



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# File 'lib/livetext/expansion.rb', line 22

def expand_variables(str)
  rx = Regexp.compile("(?<result>" + Var + Dotted + ")")
  buffer = ""
  loop do |i|
    case                           # var or func or false alarm
    when str.empty?                # end of string
      break
    when str.slice(0..1) == "\\$"  # escaped, ignore it
      str.slice!(0..1)    
      buffer << "$"
    when str.slice(0..1) == "$$"   # func?
      buffer << str.slice!(0..1)    
    when str.slice(0) == "$"       # var?
      vmatch = rx.match(str)
      if vmatch.nil?
        buffer << str.slice!(0)
        next
      end
      vname = vmatch["result"]
      str.sub!(vname, "")
      vsym = vname[1..-1].to_sym
      vars = @live.vars
      buffer << vars.get(vsym)
    else                           # other
      char = str.slice!(0)
      buffer << char
    end
  end
  buffer
end

#format(line) ⇒ Object 



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# File 'lib/livetext/expansion.rb', line 15

def format(line)
  return "" if line == "\n" || line.nil?
  with_vars = expand_variables(line)
  with_func = expand_function_calls(with_vars)
  formatted = Formatter.format(with_func)
end

#funcall(name, param) ⇒ Object 



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# File 'lib/livetext/expansion.rb', line 53

def funcall(name, param)
  err = "[Error evaluating $$#{name}(#{param})]"
  name = name.gsub(/\./, "__")
  return if self.send?(name, param)
  fobj = ::Livetext::Functions.new
  result = fobj.send(name, param) rescue err
  result.to_s
end