CODEWITHSUNDEEP
stringlua
user11954069
user11954069

Reputation:

Capture strings NOT enclosed by balanced parentheses in Lua

Lua patterns include %b() and the like to capture strings enclosed by paired strings (in this case, parentheses). However, what if I want to capture everything except "%b()"?

What I've tried:

str = "A time ago (hello)"
string.gsub(str, "[^%b()]", "a")

But the result is aaaaaaaaaaa(aaaaa), i.e., it replaces everything except paired parentheses. What I want to get is aaaaaaaaaaa(hello) instead.

Edit

For more context, what I want is to make the following

myfunction("A nice (house) on an (island)")
--should ignore (house) and (island)
--should work like string.gsub(str, "%w+", "bla"), for instance
--by ignoring enclosed strings
bla bla (house) bla bla (island)

Upvotes: 1

Views: 298

Answers (1)

lhf
lhf

Reputation: 72422

Try this code:

s="A nice (house) on an (island)"
print(s:gsub("(.-)(%b())",function (a,b) return a:gsub("%w+","bla")..b end))

This works, except that it does not handle the words after the last parentheses. The solution is to make sure that the input is uniform:

s="A nice (house) on an (island) in the Pacific" .. "()" -- here!
print(s:gsub("(.-)(%b())",function (a,b) return a:gsub("%w+","bla")..b end))

and then remove the trailing () in the output.

Upvotes: 0

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