another rust solution

1 files changed, 70 insertions, 0 deletions

diff --git a/GC.rs b/GC.rs
new file mode 100644
index 0000000..62dd706
--- /dev/null
+++ b/GC.rs
@@ -0,0 +1,70 @@
+use io::{println,stdin,Reader,ReaderUtil};
+use str::{push_str,unshift_char,each_char,len};
+
+const EOF: char = -1 as char;
+
+struct FASTAReader {
+    in:              Reader,
+    priv mut peeked: char,
+}
+
+impl FASTAReader {
+    static fn new() -> FASTAReader {
+        FASTAReader { in: stdin(), peeked: EOF }
+    }
+
+    fn read_line(&self) -> ~str {
+        let mut line = self.in.read_line();
+        if self.peeked != '>' {
+            unshift_char(&mut line, self.peeked);
+        }
+        self.peeked = self.in.read_char();
+        line
+    }
+
+    fn read_sequence(&self) -> (~str, ~str) {
+        if self.peeked == EOF {
+            self.peeked = self.in.read_char();
+        }
+
+        let name = self.read_line();
+        let mut dna = ~"";
+        while !self.in.eof() && self.peeked != '>' {
+            let line = self.read_line();
+            push_str(&mut dna, line);
+        }
+        (name, dna)
+    }
+
+    fn each_sequence(&self, cb: fn(~str, ~str) -> bool) {
+        while !self.in.eof() {
+            let (name, dna) = self.read_sequence();
+            cb(name, dna);
+        }
+    }
+}
+
+pure fn gc_content(dna: ~str) -> float {
+    let mut content = 0;
+    for each_char(dna) |ch| {
+        match ch {
+            'C' | 'G' => content += 1,
+            _         => (),
+        }
+    }
+    (content as float) / (len(dna) as float)
+}
+
+fn main() {
+    let reader = FASTAReader::new();
+    let mut (max_name, max_gc) = (~"", -1f);
+    for reader.each_sequence |name, dna| {
+        let gc_content = gc_content(dna);
+        if gc_content > max_gc {
+            max_gc = gc_content;
+            max_name = name;
+        }
+    }
+    println(max_name);
+    println(fmt!("%.6f", max_gc * 100f));
+}