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@Dubhead
Created May 23, 2013 07:08
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calculating GC content in Dart
#!/usr/local/dart/dart-sdk/bin/dart
// gc.dart
// cf. http://saml.rilspace.org/moar-languagez-gc-content-in-python-d-fpc-c-and-c
import 'dart:io';
import 'dart:async';
main()
{
int gcCount = 0;
int atCount = 0;
var f = new File("Homo_sapiens.GRCh37.67.dna_rm.chromosome.Y.fa");
var inputStream = f.openRead();
inputStream
.transform(new StringDecoder(Encoding.ASCII))
.transform(new LineTransformer())
.listen(
(String line) {
if (line.startsWith(">")) {
return;
}
int lineLen = line.length;
for (var i = 0; i < lineLen; ++i) { // for each char in line
switch (line[i]) {
case 'G':
case 'C':
gcCount += 1;
break;
case 'A':
case 'T':
atCount += 1;
break;
}
}
},
onDone: () { print(gcCount * 100 / (gcCount + atCount)); },
onError: (e) { print(e.toString()); });
}
// eof vim:set syntax=dart shiftwidth=2 expandtab:
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