pallet.thread-expr

A library containing macros for use in clojure threading expressions (using ->).

See reference documentation and annotated source.

Examples

Threaded arg exposure:

arg-> exposes the threaded arg, binding it to the supplied variable. For example:

(->2
(arg-> [x]
(* (inc x))))
;=> 6

Expands to:

(->2 ((fn [arg] (let [x arg] (-> arg (* inc x))))))
;=> 6

Note the extra set of parens in the expansion; the threading macro feeds the current argument in as arg, binds it to the supplied var using let, and resumes threading for all forms inside of arg->.

Threaded list comprehension:

The following use of for->:

(->1
(for-> [x [123]]
(+ x)))
;=> 7

Expands to:

(->1
(+1)
(+2)
(+3))
;=> 7

Installation

thread-expr is distributed as a jar, and is available in the clojars repository.

Installation is with leiningen or your favourite maven repository aware build tool.

lein/cake project.clj

:dependencies [[com.palletops/thread-expr "1.3.0"]]

maven pom.xml

<dependencies>
<dependency>
<groupId>org.cloudhoist</groupId>
<artifactId>thread-expr</artifactId>
<version>1.3.0</version>
</dependency>
<dependencies>
<repositories>
<repository>
<id>clojars</id>
<url>http://clojars.org/repo</url>
</repository>
</repositories>

License

Licensed under EPL

Copyright 2011, 2012, 2013 Hugo Duncan.