pipes

  1. pipes
    1. Description
      1. pipes
      2. pipe
      3. pipe*
      4. flip*
    2. Examples
    3. Requirements
  2. Last update
  3. Author
  4. License
  5. Version History

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

[procedure] (pipes)
[procedure] (pipes sym)

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

pipe

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

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*

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

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

flip*

[procedure] (flip* proc)

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

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.

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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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Version History

1.0
initial import