Perlish wrapper for Julia's match

README.md

PerlishMatch

Perlish wrapper for Julia's match: unpacks captures into variables. It could be slower than using match in the Julian way.

Installation

Pkg.clone("https://gist.github.com/e689e59f4ed7da1ddf78.git", "PerlishMatch/src")

Example

julia> using PerlishMatch

julia> uniprot, first_pos, last_pos = m(r"^(\w+)/(\d+)-(\d+)","O83071/192-246")
("O83071","192","246")

julia> uniprot
"O83071"

PerlishMatch.jl

module PerlishMatch

	export m, @m

	function tuple_nothing(n::Int)
		([nothing for i in 1:n]...)
	end

	function count_groups(regex::Regex)
		opening = 0
		closing = 0
		for char in regex.pattern
			if char == '('
				opening += 1
			elseif char == ')'
				closing += 1
			end
		end
		if opening == closing
			return(opening)
		else
			throw(ErrorException("Different number of '(' and ')'"))
		end
	end
	
	"""
	Perlish wrapper for Julia's match. 
	Returns a tuple of captures. You can unpack the tuple into variables.
	It could be slower than using match in the Julian way.
	
	## Example
	```
	julia> uniprot, first_pos, last_pos = m(r"^(\w+)/(\d+)-(\d+)","O83071/192-246")
	("O83071","192","246")
	
	julia> uniprot
	"O83071"
	
	```
	"""
	function m(regex::Regex, args...)
		cap = match(regex, args...)
		if cap !== nothing
			return(cap.captures...)
		else
			return(tuple_nothing(count_groups(regex)))
		end
	end

	macro m(exp)
		if exp.head == :(=) && exp.args[1].head == :(tuple) &&  exp.args[2].head == :(call) 
			@eval begin
				cap = $(exp.args[2])
				$(exp.args[1]) = cap !== nothing ? (cap.captures...) : tuple_nothing(length($(exp.args[1])))
			end
		end
	end
	
end