Lua Matching vs Regex

Solar2D Lua Language
1

I want to match an equivalent of the regex pattern:

{(([^{}]+)|(?R))*}

which basically matches first { … } pair+content in a string. I cannot find a complete reference for what the lua pattern matching supports (everything either refers to compiled modules/extensions or alternate libs from string.match). I’m hoping someone here can help me, at least, with the Lua equivalent to R!

2

is this the type of reference you’re searching ?

http://www.lua.org/manual/5.1/manual.html#5.4.1
http://www.lua.org/pil/20.2.html

can you give some examples of what you’re trying to match ? that regex seems like more than one would need just to get content between two {}s.

here are some Lua examples:

local str, pat -- easy data str = "{Hello} in between {World} 1234 {123456}" pat = "{(%w+)}" for word in string.gmatch(str, pat) do print(word) end print("------") -- complex data str = "{'Hell0'} in between {W0rld} 1234 {1234} {'.4.4.4.'}" pat = "{([%w'.]+)}" for word in string.gmatch(str, pat) do print(word) end

-- output 2013-06-30 15:25:33.418 Corona Simulator[25712:f03] Hello 2013-06-30 15:25:33.418 Corona Simulator[25712:f03] World 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 123456 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] ------ 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 'Hell0' 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] W0rld 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 1234 2013-06-30 15:25:33.420 Corona Simulator[25712:f03] '.4.4.4.'

cheers,
dmc

3

Thanks for the links.

I was trying to guard against nested curlies to match first outermost pairing. This would allow for iteration through a string with irregular separators between json encoded strings.

I have solved the problem a different way, but this has highlighted the Lua matching seems primitive. Corona has to live in a modern-day ecosystem where protocols and formats are rather complex and more powerful pattern matching is needed.

4

is this the type of reference you’re searching ?

http://www.lua.org/manual/5.1/manual.html#5.4.1
http://www.lua.org/pil/20.2.html

can you give some examples of what you’re trying to match ? that regex seems like more than one would need just to get content between two {}s.

here are some Lua examples:

local str, pat -- easy data str = "{Hello} in between {World} 1234 {123456}" pat = "{(%w+)}" for word in string.gmatch(str, pat) do print(word) end print("------") -- complex data str = "{'Hell0'} in between {W0rld} 1234 {1234} {'.4.4.4.'}" pat = "{([%w'.]+)}" for word in string.gmatch(str, pat) do print(word) end

-- output 2013-06-30 15:25:33.418 Corona Simulator[25712:f03] Hello 2013-06-30 15:25:33.418 Corona Simulator[25712:f03] World 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 123456 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] ------ 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 'Hell0' 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] W0rld 2013-06-30 15:25:33.419 Corona Simulator[25712:f03] 1234 2013-06-30 15:25:33.420 Corona Simulator[25712:f03] '.4.4.4.'

cheers,
dmc

5

Thanks for the links.

I was trying to guard against nested curlies to match first outermost pairing. This would allow for iteration through a string with irregular separators between json encoded strings.

I have solved the problem a different way, but this has highlighted the Lua matching seems primitive. Corona has to live in a modern-day ecosystem where protocols and formats are rather complex and more powerful pattern matching is needed.