bufio.ReadRune

R=rsc
DELTA=32  (29 added, 0 deleted, 3 changed)
OCL=19809
CL=19913

diff --git a/src/lib/bufio.go b/src/lib/bufio.go
index f41c4cd3d28601dcea82c9f62c0765a1d8f29708..11813d6c646d0c5517b55f4781eb33143ba7f55a 100644 (file)
--- a/src/lib/bufio.go
+++ b/src/lib/bufio.go
@@ -3,8 +3,12 @@
 // license that can be found in the LICENSE file.
 
 package bufio
-import "os"
-import "io"
+
+import (
+       "os";
+       "io";
+       "utf8";
+)
 
 
 // TODO:
@@ -65,7 +69,7 @@ func (b *BufRead) Fill() *os.Error {
        }
 
        // Slide existing data to beginning.
-       if b.w >  b.r {
+       if b.w > b.r {
                CopySlice(b.buf[0:b.w-b.r], b.buf[b.r:b.w]);
                b.w -= b.r;
        } else {
@@ -140,6 +144,30 @@ func (b *BufRead) UnreadByte() *os.Error {
        return nil
 }
 
+// Read a single Unicode character; returns the rune and its size.
+func (b *BufRead) ReadRune() (rune int, size int, err *os.Error) {
+       for b.r + utf8.UTFMax > b.w && !utf8.FullRune(b.buf[b.r:b.w]) {
+               n := b.w - b.r;
+               b.Fill();
+               if b.err != nil {
+                       return 0, 0, b.err
+               }
+               if b.w - b.r == n {
+                       // no bytes read
+                       if b.r == b.w {
+                               return 0, 0, EndOfFile
+                       }
+                       break;
+               }
+       }
+       rune, size = int(b.buf[b.r]), 1;
+       if rune >= 0x80 {
+               rune, size = utf8.DecodeRune(b.buf[b.r:b.w]);
+       }
+       b.r += size;
+       return rune, size, nil
+}
+
 // Helper function: look for byte c in array p,
 // returning its index or -1.
 func FindByte(p *[]byte, c byte) int {

diff --git a/src/lib/utf8.go b/src/lib/utf8.go
index 7b0f15d8f70cbeb657ec7db22ec509a02774df6a..1375e8e50c507537efa0045585a1bbb27ae00055 100644 (file)
--- a/src/lib/utf8.go
+++ b/src/lib/utf8.go
@@ -7,6 +7,7 @@
 package utf8
 
 export const (
+       UTFMax = 4;
        RuneError = 0xFFFD;
        RuneSelf = 0x80;
        RuneMax = 1<<21 - 1;