#	ESCAPE
#
#	Interpret Icon literal escapes
#
#	William H. Mitchell
#
#	Last mofied 2/1/86
#

procedure escape(s)
   ns := ""
   s ? while c := move(1) do {
      ns ||:= if c == "\\" then case c2 := (move(1) | "") of {
      "b":  "\b"
      "d":  "\d"
      "e":  "\e"
      "f":  "\f"
      "l":  "\n"
      "n":  "\n"
      "r":  "\r"
      "t":  "\t"
      "v":  "\v"
      "'":  "'"
      "\"":  "\""
      "x":  hexcode()
      "^":  ctrlcode(move(1))
      any('01234567',c2) & c2:  octcode(c2)
      default:  c2
      } else c
      }
   return ns
end

procedure hexcode()
   static cdigs
   initial cdigs := ~'0123456789ABCDEFabcdef'
   
   move(i := 2 | 1) ? s := tab(upto(cdigs) | 0)
   move(*s - i)
   return &cset[integer("16r" || s) + 1]
end

procedure octcode(c)
   static cdigs
   initial cdigs := ~'01234567'
   
   move(-1)
   move(i := 3 | 2 | 1) ? s := tab(upto(cdigs) | 0)
   move(*s - i)
   return &cset[integer("8r" || s) + 1]
end

procedure ctrlcode(s)
   return &cset[find(map(s),&lcase) + 1]
end