Metaxal

#lang racket
(require (for-syntax racket/base
                     syntax/parse)
         racket/list
         racket/match)

;; Related post: http://jeapostrophe.github.io/2013-11-12-condd-post.html

(define (f-condd4 l)
  (condd4

Metaxal

#lang racket
(require measures)

(define-syntax-rule (define-units-contract name m1)
  (define name
         (make-flat-contract
          #:name 'name
          #:first-order
          (λ(m2)(measure-units-equal? m1 m2)))))

Metaxal

#lang slideshow
(require bazaar/slideshow/slideshow-tree)

(define t1 '(a (b1 (c1 d1 d2) 
                   (c2 d3 d4)) 
               (b2 (c3 d5) 
                   c4)))

(draw-tree-top-left-right 
 (tree-map t1 (λ(x)(t (symbol->string x))))

Metaxal

#lang racket
(require framework
         racket/gui/base)

(provide theme->frame)

; Call (theme->frame) to open a frame with the current style as an info.rkt file

(color-prefs:register-info-based-color-schemes)

Metaxal

#lang racket/base

; One way to define a logger
(define lg (make-logger 'my-logger))
; Define a receiver for this logger, along with a log level
(define rc (make-log-receiver lg 'error)) ; also try with 'debug

; Another way to define a logger, with additional forms
(define-logger lg2)
(define rc2 (make-log-receiver lg2-logger 'debug))

Metaxal

# This is not really a script and should be run line by line instead.
# With the admin user, do the following.

# Install Optware (ipkg) 
# and configure the admin's path.
# http://wiki.qnap.com/wiki/Install_Optware_IPKG

# Install correct versions of basic tools,
# otherwise the following will not work.
ipkg install coreutils make find grep sed gawk

Metaxal

#lang racket
(require (for-syntax syntax/parse))

;;; Allow every argument to be passed by-name or by-position in a procedure call.
;;; Keywords do not need to apper in procedure headers in definitions.
;;; Accepts rest and keyword-rest arguments.
;;; A new definition of instantiate is also given to resemble this procedure call style.
;;; Resources:
;;; - http://www.mail-archive.com/[email protected]/msg08846.html
;;; - https://gist.github.com/Metaxal/5851215

Metaxal

#lang racket
(require (for-syntax syntax/parse
                     racket/syntax))

;;; Recognizes super-id and keyword arguments of struct.

;;; Caveats:
;;; - does not recognize per-field options (like per-field mutability).
;;; - the hash table uses the symbol of the super-id, but should use the binding instead.
;;; - may not work if the default expr depends on bindings not available in the context of the 

Metaxal

#lang racket
(require (for-syntax syntax/parse))

(define-syntax (and/def stx)
  (syntax-parse stx
                #:literals (define define-values)
    [(_) #'#t]
    
    [(_ [define-values (var:id ...) val:expr] rest ...)
     #'(let-values ([(var ...) val])

Metaxal

#lang racket

(require racket/sandbox)

#|
Self-link: http://gist.github.com/Metaxal/5723825
 
Original idea by Eliezer Yudkowski and Alex Mennen:
http://lesswrong.com/lw/7f2/prisoners_dilemma_tournament_results/4ru9
http://lesswrong.com/lw/hmx/prisoners_dilemma_with_visible_source_code/