问题
Are there languages or tools that support the parsing of regexes on a character-by-character basis?
I think this may be equivalent to "regexes on streams" which is something that seems to be one of the features of the upcoming Perl version 6.
Basically I want to do this because I'm building a tool that does translation of a terminal stream over a pseudo-terminal, and it occurred to me that the ultimate sort of flexibility that should be attainable is by allowing the specification of regex-replace expressions.
The use case is that I want to allow my mouse scroll events to be passed to a naive program such as the less pager, which means my tool (which spawns less over a PTY) will be doing something like issuing the code \x1b[?1000h which switches on mouse reporting, and then subsequently translating every mouse wheel escape code received thereafter such as \x1b[M!! (the last several chars encode the mouse position within the terminal and should be ignored but also stripped) into the \x1b[A Up-arrow code.
As you can see being able to specify a regex that works on the stdin terminal-reading stream to generate the translated stream to send to the slave pty would be ideal.
Do I need to wait for Perl 6 to be able to achieve this? There must be particular reasons for why regex engines generally require having the whole string available?
It's pretty obvious I don't need the full blown power of regex here. I can speculate for instance that it might be the case that supporting backtracking makes stream-parsing regex impossible.
So since I don't need backtracking maybe there is some sort of light-weight regex engine out there that provides a stream API. It just seems like taking advantage of some form of parsing system (if one exists that is suitable) would be smarter than building something arbitrary.
回答1:
Looks like s2p is an example of something that I can use.
In particular, the potential of being able to set $| to not do line-buffering.
Actually I don't think this will work. It seems to be built around lines and uses the s operator to run regex.
来源：https://stackoverflow.com/questions/16114749/regular-expression-incremental-parsing