chickadee » pipes

pipes

Description

Besides the documentation procedure, this module exports three routines, the macros pipe and pipe* as well as the procedure flip*. The first macro takes a variable and a sequence of partial combinations, calls the first combination with the variable as additional left argument and hands the result successively to the next combination. For example

 (pipe 3 (+ 1) (- 2) (* 5))

will return 10.

Sometimes its necessary to add the variable to the right of the argument list. To achieve this simply replace the combination's name, fn say, with (flip* fn): flip* flips the first argument of fn to the end, and thus is a generalisation of flip in (chicken base).

pipes

pipesprocedure
pipes symprocedure

documentation procedure: the first call shows the list of exported symbols, the second the documentation of sym.

pipe

(pipe x (fn . xs) ...)syntax

calls each combination with the result of applying its combination to the left as first argument. In particular (pipe x (fn . xs)) is (fn x . xs) and (pipe x (fn . xs) (gn . ys)) is (gn (fn x . xs)).

pipe*

(pipe* (fn . xs) ...)syntax

pipe as a procedure: (pipe* (fn . xs) ...) is (lambda (x) (pipe x (fn . xs) ...))

flip*

flip* procprocedure

flips the arguments of proc by shifting the first one to the end.

Examples

((flip* list)) ; -> '()
((flip* list) 1) ; -> '(1)
((flip* list) 1 2) ; -> '(2 1)
((flip* list) 1 2 3 4) ; -> '(2 3 4 1)
((flip* map) '(0 1 2) add1) ; -> '(1 2 3)

(pipe 5) ; -> 5
(pipe 5 (+ 1)) ; -> 6
(pipe 5 (- 10) (positive?)) ; -> #f
(pipe 5 (- 10) (negative?)) ; -> #t
(pipe 10 ((flip* list) 1 2 3 4)) ; -> '(1 2 3 4 10)
(pipe 10 (list 1 2 3 4)) ; -> '(10 1 2 3 4))
(pipe '(0 1 2) ((flip* map) add1)) ; -> '(1 2 3))
(pipe 0 (list 1 2 3)) ; - > '(0 1 2 3)) 
(pipe 0 ((flip* list) 1 2 3)) ; - > '(1 2 3 0))

Requirements

none

Last update

Mar 28, 2019

Author

Juergen Lorenz

Repository

This egg is hosted on the CHICKEN Subversion repository:

https://anonymous@code.call-cc.org/svn/chicken-eggs/release/5/pipes

If you want to check out the source code repository of this egg and you are not familiar with Subversion, see this page.

License

Copyright (c) 2016-2019, 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.

Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
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. 
  
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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
HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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Version History

1.0
initial import

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