1 01/12/82  APL Search Paths
 2 
 3 The MR9.0 release of APL offers the ability for the site and/or the
 4 user to specify search paths to be used by the APL executive when
 5 searching for an external function or a workspace to be loaded.  This
 6 permits the site and/or the user to designate one or more directories
 7 as libraries of workspaces and external functions.  If no search paths
 8 are defined for APL, workspaces and external functions are searched
 9 for in the same way as with previous versions of APL.
10 
11 The user may determine if the site has defined search paths for APL
12 and, if so, what they are, by entering the command 'print_search_paths
13 apl'.  If the site does not define any search paths for APL, the user
14 may do so with the 'set_search_paths' command.  Once search paths have
15 been defined for APL, the user may use the 'add_search_paths' and
16 'delete_search_paths' commands to modify them.
17 
18 
19 Effect of search paths on the ')LOAD' command:
20 If the workspace in a ')LOAD' command is identified by an entry name
21 rather than an absolute or relative pathname, it is searched for first
22 in the directories specified by any APL search paths, and then in the
23 user's working directory.
24 
25 
26 Effects of search paths on the ')DFN', ')MFN' & ')ZFN' commands:
27 If the function in an external function definition command is
28 identified by a reference name rather than an absolute or relative
29 pathname, it is searched for first among the already initiated
30 segments, then in the directories specified by any APL search paths,
31 and finally according to the current search rules.
32 
33 
34 Effects of search paths on the 'qCALL' function:
35 'qCALL' searches for the external routine it is to invoke first among
36 the already initiated segments, then in the directories specified by
37 any APL search paths, and finally according to the current search
38 rules.  If any of the arguments to the external routine to be called
39 are themselves external routines, they are searched for in the same
40 way.