View Full Version : .net RegExp matches

12 December 2008, 12:25 PM
Hey Folks,

I'm really enjoying everything .net is bringing to the party at the moment, even if some of it is a bit hard to get going with sometimes.

Current head-scratcher is how to read valid matches from a regular expression match into something usable. As with quite a few .net constructs certain items seem to be recursive in their nature, which is frustrating when you're trying to find something.

Here's my source text...
name "MaxScript Packager"
description "Easily create zipped MaxScript (.mzp) packages"

And here's the Regular Expression code I'm using to extract the variable/value pairs

rx = dotNetClass "System.Text.RegularExpressions.RegEx"
pattern = "(name|description)\s+\"([^\"]+)\""
matches = rx.matches str pattern
for i = 0 to matches.count - 1 do print matches[i]

No matter what I do, I can only seem to extract the original text, not the parenthesized captures. What I would expect is something like:

#("name", "MaxScript Packager")
#("description", "Easily create zipped MaxScript (.mzp) packages")

Any help would be appreciated!

12 December 2008, 06:20 PM
be afraid - be very afraid

result = #()
str = "name \"MaxScript Packager\" name\ndescription \"Easily create zipped MaxScript (.mzp) packages\""
rx = dotNetClass "System.Text.RegularExpressions.RegEx"
pattern = "(?<1>name|description)\s+\"(?<2>[^\"]+)\""

m = rx.match str pattern
while m.Success do (
append result (
for i = 1 to (m.Groups.count - 1) collect (
m = m.nextMatch()

Edit: begone, ye devil print statement

12 December 2008, 06:49 PM
How strange to use the Iterator pattern! And where the hell are people supposed to find that out?

On the plus side at least that code can be packaged up into something rather useful, so I thank you graciously, Sir!

You know, I often wonder how you know as much as you seem to. Are you actually a distant cousin of the Enigma Machine?

Thanks again,

12 December 2008, 06:55 PM
And a nice tidy function for those following in my footsteps:
function regexMatch source pattern options: =
local groups
local results = #()
local rx = dotNetClass "System.Text.RegularExpressions.RegEx"
local matches = if options == unsupplied then rx.match source pattern else rx.match source pattern options
while matches.Success do
groups = for i = 1 to matches.Groups.count - 1 collect matches.groups.item[i].value
matches = matches.nextMatch()
append results groups

12 December 2008, 12:52 AM
..How strange to use the iterator ... Where the hell ...

just as an aside, you don't have to use rx.match's own iterator. You could have gone with rx.matches, if you wanted....

matches = rx.matches source pattern
for matchIdx = 0 to matches.count-1 do
currentMatch = matches.item[matchIdx]
for groupIdx = 0 to currentMatch.groups.count-1 do (
currentGroup = currentMatch.groups.item[groupIdx]
append results currentGroup.value

but ZB's / your new way is nicer. The only problem with your original was that the matchcollection and groupcollection don't map straight to MXS arrays.

12 December 2008, 01:13 AM
correct - it's just nice to not have downstream code break due to a change in the regex pattern later on :)

bytheby, dave, I think your function is not defining rx? might be good to inline that in the function? (or have the user pass one as a parameter, I suppose)

12 December 2008, 02:04 AM
Good spot! Had test code running in global scope...

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