author | wenzelm |
Fri, 19 Jun 2020 16:12:32 +0200 | |
changeset 71960 | 6a64205b491a |
parent 71601 | 97ccf48c2f0c |
child 75393 | 87ebf5a50283 |
permissions | -rw-r--r-- |
/* Title: Pure/PIDE/document_id.scala Author: Makarius Unique identifiers for document structure. NB: ML ticks forwards > 0, JVM ticks backwards < 0. */ package isabelle object Document_ID { type Generic = Long type Version = Generic type Command = Generic type Exec = Generic val none: Generic = 0 val make: Counter = Counter.make() def apply(id: Generic): String = Value.Long.apply(id) def unapply(s: String): Option[Generic] = Value.Long.unapply(s) }