Re: ":" in Scheme names.

[Aubrey Jaffer]

 | Date: Tue, 5 Nov 2002 08:22:03 +0200 (IST)
 | From: Eli Zaretskii <address@hidden>
 | 
 | On Mon, 4 Nov 2002, Aubrey Jaffer wrote:
 | 
 | > Putting a TAB character after the ":" in index entries in .info
 | > files does not screw up indexing for the info (4.1) program or
 | > emacs (21.2).
 | 
 | There's more than just 2 Info readers out there.  We shouldn't
 | break any of them.  (Although I don't think any amount of
 | whitespace after the colon will break any of them.)
 | 
 | > The next version of makeinfo would put tabs after ":" in index
 | > entries.  New versions of info readers would treat ":<TAB>" as
 | > the separator if present; falling back to ":" if tabs are absent.
 | 
 | Thank you for your suggestion.
 | 
 | However, I don't think it will work to rely on whitespace after the
 | colon: whitespace is generally ignored by the Info readers when
 | they look for node names and other keywords.  Likewise, TABs and
 | SPACEs (and newlines as well) are treated the same.

When I interpose a newline in an index entry, /usr/bin/info can still
index it, but Emacs says "Info-index: No `make-color' in index".

 | These assumptions are buried deep inside the low-level search
 | routines of the Info reader, which don't really know whether they
 | are looking for an index entry or something else, so it's not easy
 | to change that.

You just said there are many info readers -- so the difficulty you
cite with "the Info reader" will not apply to all readers.  You opined
that whitespace shouldn't break any reader.  If a method fixes some
readers and does no harm to the others, then it is worth doing.

 | As an example, consider this entry from my DIR file:
 | 
 |  * mkfifo: (fileutils)mkfifo invocation.         Create FIFOs: (named pipes).
 | 
 | There are two colons with whitespace after them here; how do you
 | tell Info which one to take as the significant delimiter?  The part
 | to the right of the node name is free text, so anything can go
 | there.

The DIR file is not an index.  Typing 'I' to /usr/bin/info provokes
"No indices found."  Emacs info-mode searches the TexInfo index.

 | As Karl said, this is a hard problem, and it's not limited to the
 | colon (a period has similar problems here).

It is a hard problem only if you insist on fixing all readers with the
same hammer.

 | There's a strong desire to find a solution that would be
 | back-compatible, but I suspect that the solution will be more
 | complicated than just adding a TAB.

Tabs would be backward compatible.  Old info files would index as they
do now.  Old readers would behave as they do now.

                              -=-=-=-=-

Here is a patch which fixes emacs Info-mode (with tab or not):

cd /usr/share/emacs/21.2/lisp/
diff -c /usr/share/emacs/21.2/lisp/info.el\~ /usr/share/emacs/21.2/lisp/info.el
*** /usr/share/emacs/21.2/lisp/info.el~ Fri Dec 21 14:08:17 2001
--- /usr/share/emacs/21.2/lisp/info.el  Wed Nov  6 22:30:47 2002
***************
*** 1830,1836 ****
    (interactive "sIndex topic: ")
    (let ((orignode Info-current-node)
        (rnode nil)
!       (pattern (format "\n\\* +\\([^\n:]*%s[^\n:]*\\):[ \t]*\\([^.\n]*\\)\\.[ 
\t]*\\([0-9]*\\)"
                         (regexp-quote topic)))
        node
        (case-fold-search t))
--- 1830,1836 ----
    (interactive "sIndex topic: ")
    (let ((orignode Info-current-node)
        (rnode nil)
!       (pattern (format "\n\\* +\\([^\n]*%s[^\n]*\\):[ \t]+\\([^.\n]*\\)\\.[ 
\t]*\\([0-9]*\\)"
                         (regexp-quote topic)))
        node
        (case-fold-search t))

Diff finished at Wed Nov  6 22:32:26