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Ticket #0002239 User: anonymous


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TypeWish Statussubmitted Date5-Aug-2015 08:16
Versionr3 master CategoryUnspecified Submitted byfork
PlatformAll Severitymajor Prioritynormal

Summary ANY-FUNCTION!s in PARSE invoke with match arguments (if success)
Description We see in Red the addition of KEEP and COLLECT keywords. Yet there's not really anything all that specifically sensible about PARSE needing its own KEEP and COLLECT.

It's a specific implementation of a more general desire. The desire is effectively "I want to match a rule and have the thing that rule matches implicitly grabbed as an argument to a function without naming it" Which is to say that **keep rule** is shorter than **copy x: rule (keep x)**

This points to an explosion of parse keywords to supplant existing Rebol functionality. Which leads us to ask if there might be a better way to say "I want to call this function and pass it the result of a successful match".

What if that were simply the behavior of function values in parse itself? That is to say: if a function value is hit, then if its arity N can be fulfilled by N parse rule groups satisfied without failure, then the function is run?

That would mean **collect [parse "abbbbc" ["a" keep some "b" "c"]]** would match the "a", evaluate and hold the keep as a function, satisfy **some "b"** and then realize it had enough arguments to run the function.
Example code


Assigned ton/a Fixed in- Last Update5-Aug-2015 08:23


Date User Field Action Change
5-Aug-2015 08:23 Fork Description Modified -
5-Aug-2015 08:16 Fork Ticket Added -