class lookup_id_as_file :The list (catalog) argument specifies pairs?fixenc:Pxp_core_types.I.encoding -> (Pxp_core_types.I.ext_id * string) list ->resolver
(xid,file) mapping external IDs xid
to files. The file 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.
fixenc: Overrides the encoding of the file contents. By default, the
standard rule is applied to find out the encoding of the file.
