Greg Hendershott greghendershott

Before Github deploys the Racket lexer from pygments-main via pygments.rb, the following will appear as plain, black monospace. After they deploy, this will appear color-coded:

(let ([x 0])
  x)

Then it will look similar to the Scheme lexer (below) but, as the most glaring example, brackets will not be colored as errors:

Racket user personas

Racket doesn't have a full-time "Product Manager", doesn't need one, and I'm certainly not one. However I think it might be useful to borrow an idea from PM and think about so-called user personas.

Somtimes PMs will give each persona name, and tell a story: Bob wants to accomplish X. Here's how he uses the product. What does he expect? How does he get confused? And so on.

A guide for new and/or casual contributors to Racket

Maybe you're comfortable with Git, but haven't made a pull request before.

Maybe you've made one-off pull requests, but haven't tried to contribute to the same project over time and stay in sync with the upstream project.

This guide may help. DRAFT

Given this:

#lang racket/base

(require ffi/unsafe
         ffi/unsafe/define)

...

	#lang racket

	(require (for-syntax racket/list))

	(define-syntax (foo stx)
	(syntax-case stx ()
	[(_ (as ...) (bs ...))
	#`(list #,@(append* (map list
	(syntax-e #'(as ...))
	(syntax-e #'(bs ...)))))]))

	#lang racket

	;; Ideas about making Racket `dict` access more succinct.

	;; [0]
	;;
	;; Macro to define variables and initialize them from a dict.
	;;
	;; Given a dictionary and some symbols: For each symbol, define a
	;; variable whose value is that from the dictionary (else 'UNDEFINED).

	#lang racket

	;; Goal: Define a function `getback`, which given a number
	;; returns a number with the digits reversed.
	;; Example: (getback 123) returns 321

	;; Let's break it down into a couple of steps.

	;; 1. Given a number, return it as a list of digits.
	;; number? -> (listof number?)

	#lang racket

	;; The way to catch exceptions is `with-handlers`.
	;; See http://docs.racket-lang.org/reference/exns.html
	;;
	;; You specify the type of exception, and a function to handle it. The
	;; exception object is passed to the function.
	;;
	;; For exmaple, we'll catch the "generic" `exn:fail?` with a function
	;; that we define in-place using `lambda`:

	#lang racket

	(define (f1)
	"f1")

	(define (f2)
	"f2")

	(define h (hash "f1" f1
	"f2" f2))

	#lang racket/base

	(provide ~> ~>>)

	(require (for-syntax racket/base syntax/parse))
	(require (rename-in "app.rkt" [-#%app #%app]))
	(require (only-in racket/function curry))

	;; Clojure threading macros. This is almost all courtesy of Asumu
	;; Takikawa. I did add handling of quote (symbols) to make sure it