class lookup_id_as_string :The list (catalog) argument specifies pairs?fixenc:Pxp_types.encoding -> (Pxp_types.ext_id * string) list ->
resolver
(xid,s)
mapping external IDs xid
to strings s
. The string is read if an entity with the corresponding
xid
is to be opened.
Note: SYSTEM
IDs are simply compared literally by this class,
without making
relative IDs absolute. See norm_system_id
below for how to improve this.