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author | Robert Griesemer <gri@golang.org> | 2008-03-26 09:28:57 -0700 |
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committer | Robert Griesemer <gri@golang.org> | 2008-03-26 09:28:57 -0700 |
commit | 6cbb50ac6dca6176685ba9b6e165e691f00cb47c (patch) | |
tree | 34456e7f25b74ab46ae7f6fe3b123b9155edfc87 /test/sieve.go | |
parent | 37e52258ee5067e2d6864435a7281b19b403764d (diff) | |
download | go-6cbb50ac6dca6176685ba9b6e165e691f00cb47c.tar.gz |
- new directory structure
SVN=113851
Diffstat (limited to 'test/sieve.go')
-rw-r--r-- | test/sieve.go | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/test/sieve.go b/test/sieve.go new file mode 100644 index 000000000..03538d62a --- /dev/null +++ b/test/sieve.go @@ -0,0 +1,42 @@ +// $G $F.go && $L $F.$A # don't run it - goes forever + +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package Main + +// Send the sequence 2, 3, 4, ... to channel 'ch'. +func Generate(ch *chan> int) { + for i := 2; ; i++ { + >ch = i // Send 'i' to channel 'ch'. + } +} + +// Copy the values from channel 'in' to channel 'out', +// removing those divisible by 'prime'. +func Filter(in *chan< int, out *chan> int, prime int) { + for { + i := <in; // Receive value of new variable 'i' from 'in'. + if i % prime != 0 { + >out = i // Send 'i' to channel 'out'. + } + } +} + +// The prime sieve: Daisy-chain Filter processes together. +func Sieve() { + ch := new(chan int); // Create a new channel. + go Generate(ch); // Start Generate() as a subprocess. + for { + prime := <ch; + printf("%d\n", prime); + ch1 := new(chan int); + go Filter(ch, ch1, prime); + ch = ch1 + } +} + +func Main() { + Sieve() +} |