Clojure JIRA

[MATCH-31] vector patterns should work on seq

Wed, 29 May 2013 21:30:00 -0500

This means abandoning subvec and using nth + offsets.

[MATCH-61] Exception thrown when matching using :seq when there is a seq call in the tail of the occurrences

Sat, 15 Jun 2013 22:11:30 -0500

The following match throws:

(let [q '(a) y '(b) z '(c)]
(match [q (seq y) z]
  [([_] :seq) _ _] 'a
  [_ _ _] 'b))

Looking at the macro expansion there's something clearly wrong simply with the fact that the seq expression occurs in multiple places instead of just at the beginning of the macro expansion.

[MATCH-49] Duplicate wildcard detection in pattern row doesn't account for locals

Thu, 12 Jan 2012 08:36:14 -0600

Duplicate wildcard detection in pattern row doesn't account for locals

[MATCH-40] Allow or'ing of guard functions

Mon, 21 Nov 2011 11:11:42 -0600

In order to simplify composition of guard predicates which are alternatives, allow for passing a sequence of predicates whose values when called will be or'd together.

The :when keyword currently allows passing of a vector of predicates that are and'd together.

Either case (`and` or `or`) can be achieved externally to match via composition, and an alternative might be to force explicit composition outside of core.match.

At the least, the documentation should mention that multiple predicates will be and'd together.

[MATCH-4] Optimized pattern matching on deftype/record, POJOs

Thu, 27 Oct 2011 23:42:15 -0500

(match [x]
  [({:a 0 :b 1} :type Foo)] :a0
  ...)

:a and :b would be converted to field access, i.e. (.a x)

As with primitive array matching, we should do an instance check followed by hinted field access.

We should consider adopting the deftype/record syntax.

[MATCH-72] complexity analysis

Tue, 18 Jun 2013 22:22:13 -0500

For smaller matches avoid backtracking actually greatly improves performance at the potential cost of code size. Perhaps we can devise a heuristic such that we employ the the best option available? Would need some serious hammock time.

[MATCH-65] cata matching

Sat, 15 Jun 2013 22:37:36 -0500

Dan Friedman's pattern matcher has a nice feature called cata-matching - allowing recursive matching from the match itself. Useful when writing compilers.

[MATCH-64] Improve match compile times

Sat, 15 Jun 2013 22:16:01 -0500

Improve match compile times

[MATCH-9] use case for dispatching on literals

Mon, 10 Oct 2011 22:45:51 -0500

Would speed up literal matching considerably.

[MATCH-8] Implement (p|q)ba heuristics

Sun, 4 Sep 2011 10:00:57 -0500

We should implement the rest of Maranget's suggested heuristics.

p - needed prefix
q - constructor prefix
b - branching factor
a - constructor arity

[MATCH-2] Matching Diagnostics

Sun, 16 Jun 2013 13:57:24 -0500

Communicate to the user precisely what failed to match. Conversation here: http://groups.google.com/group/clojure/browse_thread/thread/675456fba1712214. We adopt the behavior of condp since that is closer to what match does and will do (predicate dispatch)

[MATCH-7] Eliminate distinction between leaf-bind-expr and bind-expr

Fri, 21 Oct 2011 18:55:52 -0500

We should have a better considered binding model that works for all cases instead of treating leaf nodes and regular binding as different cases.