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simple-loops

This module exports some simple loop macros.

The routines

simple-loops

[procedure] (simple-loops [sym])

documentation-procedure; returns the list of exported symbols if called with no symbol, otherwise the signature of that exported symbol sym.

do-for

[syntax] (do-for var (start stop step) xpr . xprs)

for-loop: do xpr . xprs for var in [start stop[ with steps (default 1)")

do-forever

[syntax] (do-forever xpr . xprs)

endless loop: executes body xpr . xprs until exit is called

do-list

[syntax] (do-list i lst xpr . xprs)

loop along a list: execute xpr . xprs for i in lst

do-times

[syntax] (do-times i upto xpr . xprs)

loops a fixed number of times: execute xpr . xprs for i in [0 upto[

do-until

[syntax] (do-until test? xpr . xprs)

until-loop: execute xpr . xprs while test? is false

do-while

[syntax] (do-while test? xpr . xprs)

while-loop: execute xpr . xprs while test? is true

Requirements

none

Example

(import simple-loops)

    (let ((lst '()))
      (do-for i (1 65 i) (set! lst (cons i lst)))
      (reverse lst))
    ;-> '(1 2 4 8 16 32 64)

    (let ((n 3) (lst '()))
      (do-forever
        (if (zero? n) (exit lst))
        (set! lst (cons 'a lst))
        (set! n (- n 1))))
    ;-> '(a a a)

    (let ((lst '()))
      (do-list i '(1 2 3)
        (set! lst (cons i lst)))
      lst)
    ;-> '(3 2 1)

    (let ((lst '()))
      (do-times i (+ 2 3)
        (set! lst (cons i lst)))
      lst)
    ;-> '(4 3 2 1 0)

    (let ((n 4) (lst '()))
      (do-until (> 0 n)
        (set! lst (cons n lst))
        (set! n (- n 1)))
      lst)
    ;-> '(0 1 2 3 4)

    (let ((n 4) (lst '()))
      (do-while (<= 0 n)
        (set! lst (cons n lst))
        (set! n (- n 1)))
      lst)
    ;-> '(0 1 2 3 4)

Last update

Mar 17, 2019

Author

Juergen Lorenz

License

Copyright (c) 2013-2019, Juergen Lorenz
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

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notice, this list of conditions and the following disclaimer in the
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Neither the name of the author nor the names of its contributors may be
used to endorse or promote products derived from this software without
specific prior written permission. 
  
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IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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Version History

1.0

port from chicken-4