goer@ellis.uchicago.edu (Richard L. Goerwitz) (03/27/91)
Sometimes it's not convenient to insert numerous and/or large blocks
of text into hash tables at run-time. Some time ago I posted some
simple routines which make it possible to perform table-like operations
on files containing key/value combinations. I've updated these rou-
tines a bit, and expanded them slightly. Instead of reposting, I've
decided to mail them out individually to anyone who asks.
-Richard
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From the README file:
This archive contains gettext() and associated routines. Gettext()
allows the user to maintain a file of key/value combinations such that
a call to gettext(key, FNAME) will produce value. Fails if no such
key exists. Returns an empty string if the key exists, but has no
associated value in the file named in arg 2 (FNAME). Gettext() is
intended for use in situations where keys need to be associated with
very large strings (i.e. where hand-inserting these values into hash
tables would be unwieldy, and would take up a sizable chunk of
memory).
The file format is simple. Keys belong on separate lines, marked as
such by an initial colon+colon (::). Values begin on the line
following their respective keys, and extend up to the next
colon+colon-initial line or EOF. E.g.
::sample.1
Notice how the key above, sample.1, has :: prepended to mark it
out as a key. The text you are now reading represents that key's
value. To retrieve this text, you would call gettext() with the
name of the key passed as its first argument, and the name of the
file in which this text is stored as its second argument (as in
gettext("sample.1","tmp.idx")).
::next.key
etc...
For faster access, an indexing utility is included, idxtext. Idxtext
creates a separate index for a given text-base file. If an index file
exists in the same directory as FNAME, gettext() will make use of it.
Otherwise, it just does a sequential search of the entire file (this
works fine for smaller files). Please don't change a file, once
you've run idxtext on it, except to append key/value entries to it.
If you alter the indexed portion of the file in any way, you must
reindex.
If you want a list of all the keys in FNAME, call getkeys(FNAME).
Getkeys (as one might expect) resides in the file getkeys.icn. I
guess an in-core regexp pattern search could be implemented by
stuffing all keys for a given text-base file into a list, and then
using findre.icn to match patterns agains the keys (hits could
then be retrieved via calls to gettext()).
--
-Richard L. Goerwitz goer%sophist@uchicago.bitnet
goer@sophist.uchicago.edu rutgers!oddjob!gide!sophist!goer