Function to turn camelCase into separate words?

[Jasoco]

I'm looking to make a function to split a camelCase string into separate words based on which letters are capitalized. So "camelCase" would become "Camel Case". I'm sure I could figure it out myself but I am probably too tired right now to concentrate because I'm not completely sure without creating a lot of code for parsing.

I guess I'd go through the string and take note of the location of each capital letter, then split it into separate words based on those letters locations, then add spaces between them and concat them all back together. Maybe someone has already created a function to do this?

[bartbes]

How about..

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function splitCamel(s)
	local function split(char)
		return " " .. char
	end

	return (s:gsub("[A-Z]", split):gsub("^.", string.upper))
end

[Jasoco]

That works! Wow, I really do not know how to use gsub. I would have probably used so much more code than needed.

Thanks!

[Onenmaru]

How about..

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-snip-

I'm not trying to be rude, but you definitely don't want to redefine a static helper function each time you need it. Your example would be more appropriate as..

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do
   local function split(char)
      return " " .. char
   end
   function splitCamel(s)
      return (s:gsub("[A-Z]", split):gsub("^.", string.upper))
   end
end

The problem can really just be solved with gsub's nth match syntax though. Such as:

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function splitCamel(s)
  return (s:gsub("%u", " %1"):gsub("^.", string.upper))
end

[airstruck]

The problem can really just be solved with gsub's nth match syntax though.

Might also make sense to use frontier pattern depending on desired behavior for repeated caps.

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> print(("myFriedKFCChicken"):gsub("%u", " %1"):gsub("^.", string.upper))
My Fried K F C Chicken	1

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> print(("myFriedKFCChicken"):gsub(".%f[%l]", " %1"):gsub("%l%f[%u]", "%1 "):gsub("^.", string.upper))
My Fried KFC Chicken	1

[s-ol]

For reference, this is how it is done in Rails' ActiveSupport (in Ruby):

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def underscore(camel_cased_word)
  return camel_cased_word unless camel_cased_word =~ /[A-Z-]|::/
  word = camel_cased_word.to_s.gsub(/::/, '/')
  word.gsub!(/(?:(?<=([A-Za-z\d]))|\b)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1 && '_'}#{$2.downcase}" }
  word.gsub!(/([A-Z\d]+)([A-Z][a-z])/,'\1_\2')
  word.gsub!(/([a-z\d])([A-Z])/,'\1_\2')
  word.tr!("-", "_")
  word.downcase!
  word
end

https://github.com/rails/rails/blob/861 ... ods.rb#L90

[airstruck]

For reference, this is how it is done in Rails' ActiveSupport (in Ruby)

Won't do much good as far as Lua's pattern matching is concerned (no alternation, lookbehinds of other fancy stuff). That's why I suggested frontier pattern, does the same job as the lookbehind in that example.

[s-ol]

For reference, this is how it is done in Rails' ActiveSupport (in Ruby)

Won't do much good as far as Lua's pattern matching is concerned (no alternation, lookbehinds of other fancy stuff). That's why I suggested frontier pattern, does the same job as the lookbehind in that example.

I didn't mean that you should try to port it to lua, it was meant more as an algorithmic reference.