/* Title: Pure/ML/ml_syntax.scala
Author: Makarius
Concrete ML syntax for basic values.
*/
package isabelle
object ML_Syntax
{
/* int */
private def signed_int(s: String): String =
if (s(0) == '-') "~" + s.substring(1) else s
def print_int(i: Int): String = signed_int(Value.Int(i))
def print_long(i: Long): String = signed_int(Value.Long(i))
/* string */
private def print_byte(c: Byte): String =
c match {
case 34 => "\\\""
case 92 => "\\\\"
case 9 => "\\t"
case 10 => "\\n"
case 12 => "\\f"
case 13 => "\\r"
case _ =>
if (c < 0) "\\" + Library.signed_string_of_int(256 + c)
else if (c < 32) new String(Array[Char](92, 94, (c + 64).toChar))
else if (c < 127) Symbol.ascii(c.toChar)
else "\\" + Library.signed_string_of_int(c)
}
private def print_symbol(s: Symbol.Symbol): String =
if (s.startsWith("\\<")) s
else UTF8.bytes(s).iterator.map(print_byte(_)).mkString
def print_string_bytes(str: String): String =
quote(UTF8.bytes(str).iterator.map(print_byte(_)).mkString)
def print_string_symbols(str: String): String =
quote(Symbol.iterator(str).map(print_symbol(_)).mkString)
/* pair */
def print_pair[A, B](f: A => String, g: B => String)(pair: (A, B)): String =
"(" + f(pair._1) + ", " + g(pair._2) + ")"
/* list */
def print_list[A](f: A => String)(list: List[A]): String =
"[" + commas(list.map(f)) + "]"
/* properties */
def print_properties(props: Properties.T): String =
print_list(print_pair(print_string_bytes(_), print_string_bytes(_))(_))(props)
}