Regular expression debugger and optimizer.
UNDER DEVELOPMENT! PRs welcome.
Just clone and use stack to build
$ git clone https://github.com/gciruelos/egregex
$ cd egregex
$ stack build
egregex can show examples of strings that match a given regular expression.
$ stack exec egregex -- --show-matches=10 "a+b*c+"
ac
aac
acc
abc
aaac
aacc
aabc
accc
abcc
abbc
If no parameter is supplied to --show-matches
then it will enumerate all the strings that match the given regular expression
egregex can also show examples of strings that do not match a given regular expression.
$ stack exec egregex -- --show-mismatches=12 "a+b*c+"
a
b
c
aa
ab
ba
bb
bc
ca
cb
cc
The empty line is the empty string.
egregex can also enumerate strings that match or don't match several different
regular expressions.
$ stack exec egregex -- --matches="a+b*c+" --matches="a*b+c*" --doesnt-match="a*c" --show-matches=12
abc
aabc
abcc
abbc
aaabc
aabcc
aabbc
abccc
abbcc
abbbc
aaaabc
aaabcc
egregex allows the user to obtain an optimized (shorter)
version of a given regular expression.
$ stack exec egregex -- -O1 "a*a+"
a+
It can also to merge several requirements into a single regular expression.
$ stack exec egregex -- --matches="a+b*c+" --matches="ab+c*" --doesnt-match="abc" -O1
ab((cc)|(b+c))c*
If the user wants a faster result in exchange for a worse resulting regular expression, they can choose a lower optimization level.
$ stack exec egregex -- --matches="a+b*c+" --matches="ab+c*" --doesnt-match="abc" -O0
ab((cc)|(bb*c)))|(ab((cc)|(bb*c))c*(c|)
$ stack exec egregex -- --matches="a*b+c*" --doesnt-match="a*b+c*" --show-matches=3
$ stack exec egregex -- --matches="a*b+c*" --doesnt-match="a*b+c*" -O0
<impossible>
- Debugging capabilities, as in understanding why a regex doesn't match a given string. For example,
$ stack exec regex -- debug="hello" "he(lll)+o"
- Cleaner and faster code.