133 lines
4.1 KiB
Racket
133 lines
4.1 KiB
Racket
#lang hyper-literate #:♦ racket/base
|
|
♦;(dotlambda/unhygienic . racket/base)
|
|
|
|
♦title{Highlighting added, removed and existing parts in literate programs}
|
|
|
|
♦defmodule[hyper-literate/diff1]
|
|
|
|
Highly experimental. Contains bugs, API may change in the future.
|
|
|
|
♦defproc[(init) any/c]{
|
|
|
|
For now, the ♦racket[init] function must be called somewhere in documents
|
|
which use ♦racketmodname[hyper-literate/diff1]. It produces helper values
|
|
which must be inserted in the scribble document. Simply adding this to the
|
|
document should be enough:
|
|
|
|
♦codeblock|{
|
|
#lang hyper-literate #:♦ racket/base
|
|
♦(init)}|}
|
|
|
|
♦defform[(hlite name pat . body)]{
|
|
|
|
Like ♦racket[chunk], but highlights parts of the ♦racket[body] according to
|
|
the pattern ♦racket[pat].
|
|
|
|
The ♦racket[pat] should cover the whole ♦racket[body], which can contain
|
|
multiple expressions. The ♦racket[pat] can use the following symbols:
|
|
|
|
♦itemlist[
|
|
♦item{♦racket[=] to indicate that the following elements are ``normal'' and
|
|
should not be highlighted in any special way.}
|
|
♦item{♦racket[/] to indicate that the following elements were already
|
|
existing in previous occurrences of the code (the part is dimmed)}
|
|
♦item{♦racket[+] to indicate that the following elements are new (highlighted
|
|
in green)}
|
|
♦item{♦racket[-] to indicate that the following elements are removed
|
|
(highlighted in red). Removed elements are also removed from the actual
|
|
executable source code. If a removed element contains one or more normal, new
|
|
or dimmed elements, these children are spliced in place of the removed
|
|
element.}
|
|
♦item{Other symbols are placeholders for the elements}]
|
|
|
|
In the following example, the ♦racket[1] is highlighted as removed (and will
|
|
not be present in the executable code), the ♦racket[π] is highlighted as
|
|
added, and the rest of the code is dimmed:
|
|
|
|
♦codeblock|{
|
|
#lang hyper-literate #:♦ racket/base
|
|
♦hlite[<my-code> {/ (def args (_ - _ + _ / . _))}
|
|
(define (foo v)
|
|
(+ 1 π . v))]}|
|
|
|
|
It produces the result shown below:}
|
|
|
|
♦require[hyper-literate/diff1]
|
|
♦(init)
|
|
|
|
♦hlite[<my-code> {/ (def args (_ - _ + _ / . _))}
|
|
(define (foo v)
|
|
(+ 1 π . v))]
|
|
|
|
♦section{Example}
|
|
|
|
You can look at the source code of this document to see how this example is
|
|
done.
|
|
|
|
♦require[hyper-literate/diff1]
|
|
♦(init)
|
|
|
|
We define the function foo as follows:
|
|
|
|
♦chunk[<foo>
|
|
(define (foo v)
|
|
(+ 1 v))]
|
|
|
|
However, due to implementation details, we need to add ♦racket[π] to this
|
|
value:
|
|
|
|
♦hlite[|<foo'>| {/ (def args (_ _ + _ / . _))}
|
|
(define (foo v)
|
|
(+ 1 π . v))]
|
|
|
|
In order to optimise the sum of ♦racket[1] and ♦racket[π], we extract the
|
|
computation to a global helper constant:
|
|
|
|
|
|
♦hlite[|<foo''>| {+ _ _ / (def args '(+ a - b + c d . e) (_ - _ _ + _ / _)) = _}
|
|
(define π 3.1414592653589793)
|
|
(define one-pus-π (+ 1 π))
|
|
(define (foo v)
|
|
'(a b c d . e)
|
|
(+ 1 π one-pus-π v))0]
|
|
|
|
♦hlite[|<www>| (/ (quote (+ a - b + c d . e))
|
|
(quote (+ a - b + c d . e))
|
|
(= quote (+ a - b + c d . e))
|
|
(quote (quote (+ a - b + c d . e))))
|
|
'(a b c d . e)
|
|
(quote (a b c d . e))
|
|
(quote (a b c d . e))
|
|
''(a b c d . e)]
|
|
|
|
The whole program is therefore:
|
|
|
|
♦hlite[|<aaa>| {- a + b = c / d}
|
|
1 2 3 4]
|
|
|
|
♦hlite[<bbb> {- (+ a - b = c)}
|
|
(x y z)]
|
|
|
|
♦hlite[<ccc> {(z - (+ a - b / . c))}
|
|
(0 (x y . z))]
|
|
|
|
♦hlite[<ddd> {(z - ((+ a a - b b / . c)))}
|
|
(0 ((x x y yy . z)))]
|
|
|
|
♦hlite[<eee> {(z - ((+ a a - b b / . c)))}
|
|
(0 ((x x y yy
|
|
. z)))]
|
|
|
|
♦chunk[<*>
|
|
(require rackunit)
|
|
|<foo''>|
|
|
(check-= (foo 42) (+ 42 1 3.1414592653589793) 0.1)
|
|
(check-equal? (list <www>)
|
|
'((a c d . e)
|
|
(a c d . e)
|
|
(a c d . e)
|
|
(quote (a c d . e))))
|
|
(check-equal? '(<aaa>) '(2 3 4))
|
|
(check-equal? '(0 <bbb> 1) '(0 x z 1))
|
|
(check-equal? '<ccc> '(0 x . z))
|
|
(check-equal? '<ddd> '(0 x x . z))] |