I have an array with 20000 records, where I want to extract all
records,
which either "begins with" or "contains" a search string.
From your description I presume your array is of the form:
tArray[<key_1>] = <some string>
tArray[<key_2>] = <some string>
...
tArray[<key_n>] = <some string>
From this you want to do this:
repeat for each key tKey in tArray
if tArray[tKey] begins with tSearchString or \
tArray[tKey] contains tSearchString then
put tKey & return after tResults
end if
end repeat
If this is the case, then the above is pretty much the best you can do.
The critical step (the one which dominates any execution time) will be
the 'begins with' and 'contains' operation - and there is little you can
do to speed these up *unless* there are constraints on the search
string.
For example, if you are actually just wanting to search for single
'words' in the records then you can pre-index all the words in the
array:
-- Build Index
repeat for each key tKey in tArray
repeat for each word tWord in tArray[tKey]
put tKey & return after tIndex[tWord]
end repeat
end repeat
-- Search for word tSearchWord
put tIndex[tSearchWord]
One thing to note is that 20000 records isn't all that many in the
modern context - so a linear search is probably not going to cause you
too many problems. However, if you are looking at this figure increasing
in orders of magnitude then at some point you should probably consider
moving to an SQLite database or something similar to store the data.
SQLite supports a 'full text search' index system, which enables fast
searches for (albeit somewhat restricted) input strings and patterns.
Warmest Regards,
Mark.
--
Mark Waddingham ~ m...@livecode.com ~ http://www.livecode.com/
LiveCode: Everyone can create apps
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