author | wenzelm |
Sat, 19 Oct 2019 11:29:39 +0200 | |
changeset 70906 | b9567a9f44a0 |
parent 66415 | 96ad7d5ff613 |
child 71601 | 97ccf48c2f0c |
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.make() def apply(id: Generic): String = Value.Long.apply(id) def unapply(s: String): Option[Generic] = Value.Long.unapply(s) }