https://github.com/alexknauth/hash-lambda

using hash-tables for rest-arguments that include keyword-arguments
https://github.com/alexknauth/hash-lambda

Last synced: about 1 month ago
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using hash-tables for rest-arguments that include keyword-arguments

• Host: GitHub
• URL: https://github.com/alexknauth/hash-lambda
• Owner: AlexKnauth
• License: mit
• Created: 2014-03-26T02:24:29.000Z (almost 11 years ago)
• Default Branch: master
• Last Pushed: 2022-07-23T16:37:54.000Z (over 2 years ago)
• Last Synced: 2024-12-02T01:55:01.243Z (about 1 month ago)
• Language: Racket
• Homepage:
• Size: 942 KB
• Stars: 0
• Watchers: 3
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

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README

        
hash-lambda

===

documentation: http://pkg-build.racket-lang.org/doc/hash-lambda-toc/index.html

hash-lambdas allow you to create a "rest argument" see Declaring a Rest Argument that includes

keyword arguments. Instead of storing the arguments in a list, hash-lambda stores them in a

hash table, where you can use (hash-ref args-hash 0), etc. to access by-position arguments,

and (hash-ref args-hash '#:kw), etc. to access keyword arguments, or you can use

hash-lambda/match and use match patterns for the arguments. 

You can also use apply/hash to apply an args-hash to a function.

Examples:

```racket

> (require hash-lambda)

> (define my+

    (hash-lambda/match

     [(hash-table [0 a] [1 b])

      (+ a b)]))

> (my+ 1 2)

3

> (define/contract kinetic-energy (#:mass number? #:velocity number? . -> . number?)

    (hash-lambda/match

     [(hash-table ['#:mass mass] ['#:velocity velocity])

      (* 1/2 mass (sqr velocity))]))

> (kinetic-energy #:mass 2 #:velocity 1)

1

```