utf8 routines in go; a start.

also:
	* parse flags in testing.Main.
	* add make test in src/lib.

R=r
DELTA=323  (323 added, 0 deleted, 0 changed)
OCL=19831
CL=19850

5 files changed, 325 insertions, 0 deletions

diff --git a/src/lib/Makefile b/src/lib/Makefile
index 9ee1b5130..6ba45e018 100644
--- a/src/lib/Makefile
+++ b/src/lib/Makefile
@@ -30,11 +30,16 @@ FILES=\
 	sort\
 	strings\
 	testing\
+	utf8\
+
+TEST=\
+	utf8\
 
 clean.dirs: $(addsuffix .dirclean, $(DIRS))
 install.dirs: $(addsuffix .dirinstall, $(DIRS))
 install.files: $(addsuffix .install, $(FILES))
 nuke.dirs: $(addsuffix .dirnuke, $(DIRS))
+test.files: $(addsuffix .test, $(TEST))
 
 %.6: container/%.go
 	$(GC) container/$*.go
@@ -42,6 +47,9 @@ nuke.dirs: $(addsuffix .dirnuke, $(DIRS))
 %.6: %.go
 	$(GC) $*.go
 
+%.test: %.6
+	gotest $*_test.go
+
 %.clean:
 	rm -f $*.6
 
@@ -67,6 +75,8 @@ install: install.dirs install.files
 nuke: nuke.dirs clean.files
 	rm -f $(GOROOT)/pkg/*
 
+test: test.files
+
 # TODO: dependencies - should auto-generate
 
 bignum.6: fmt.dirinstall
diff --git a/src/lib/testing.go b/src/lib/testing.go
index 0bcdcffcd..37dcc3941 100644
--- a/src/lib/testing.go
+++ b/src/lib/testing.go
@@ -83,6 +83,7 @@ func TRunner(t *T, test *Test) {
 }
 
 export func Main(tests *[]Test) {
+	flag.Parse();
 	ok := true;
 	if len(tests) == 0 {
 		println("gotest: warning: no tests to run");
diff --git a/src/lib/utf8.go b/src/lib/utf8.go
new file mode 100644
index 000000000..7b0f15d8f
--- /dev/null
+++ b/src/lib/utf8.go
@@ -0,0 +1,162 @@
+// 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.
+
+// UTF-8 support.
+
+package utf8
+
+export const (
+	RuneError = 0xFFFD;
+	RuneSelf = 0x80;
+	RuneMax = 1<<21 - 1;
+)
+
+const (
+	T1 = 0x00;	// 0000 0000
+	Tx = 0x80;	// 1000 0000
+	T2 = 0xC0;	// 1100 0000
+	T3 = 0xE0;	// 1110 0000
+	T4 = 0xF0;	// 1111 0000
+	T5 = 0xF8;	// 1111 1000
+
+	Maskx = 0x3F;	// 0011 1111
+	Mask2 = 0x1F;	// 0001 1111
+	Mask3 = 0x0F;	// 0000 1111
+	Mask4 = 0x07;	// 0000 0111
+
+	Rune1Max = 1<<7 - 1;
+	Rune2Max = 1<<11 - 1;
+	Rune3Max = 1<<16 - 1;
+	Rune4Max = 1<<21 - 1;
+)
+
+func DecodeRuneInternal(p *[]byte) (rune, size int, short bool) {
+	if len(p) < 1 {
+		return RuneError, 0, true;
+	}
+	c0 := p[0];
+
+	// 1-byte, 7-bit sequence?
+	if c0 < Tx {
+		return int(c0), 1, false
+	}
+
+	// unexpected continuation byte?
+	if c0 < T2 {
+		return RuneError, 1, false
+	}
+
+	// need first continuation byte
+	if len(p) < 2 {
+		return RuneError, 1, true
+	}
+	c1 := p[1];
+	if c1 < Tx || T2 <= c1 {
+		return RuneError, 1, false
+	}
+
+	// 2-byte, 11-bit sequence?
+	if c0 < T3 {
+		rune = int(c0&Mask2)<<6 | int(c1&Maskx);
+		if rune <= Rune1Max {
+			return RuneError, 1, false
+		}
+		return rune, 2, false
+	}
+
+	// need second continuation byte
+	if len(p) < 3 {
+		return RuneError, 1, true
+	}
+	c2 := p[2];
+	if c2 < Tx || T2 <= c2 {
+		return RuneError, 1, false
+	}
+
+	// 3-byte, 16-bit sequence?
+	if c0 < T4 {
+		rune = int(c0&Mask3)<<12 | int(c1&Maskx)<<6 | int(c2&Maskx);
+		if rune <= Rune2Max {
+			return RuneError, 1, false
+		}
+		return rune, 3, false
+	}
+
+	// need third continuation byte
+	if len(p) < 4 {
+		return RuneError, 1, true
+	}
+	c3 := p[3];
+	if c3 < Tx || T2 <= c3 {
+		return RuneError, 1, false
+	}
+
+	// 4-byte, 21-bit sequence?
+	if c0 < T5 {
+		rune = int(c0&Mask4)<<18 | int(c1&Maskx)<<12 | int(c2&Maskx)<<6 | int(c3&Maskx);
+		if rune <= Rune3Max {
+			return RuneError, 1, false
+		}
+		return rune, 4, false
+	}
+
+	// error
+	return RuneError, 1, false
+}
+
+export func FullRune(p *[]byte) bool {
+	rune, size, short := DecodeRuneInternal(p);
+	return !short
+}
+
+export func DecodeRune(p *[]byte) (rune, size int) {
+	var short bool;
+	rune, size, short = DecodeRuneInternal(p);
+	return;
+}
+
+export func RuneLen(rune int) int {
+	switch {
+	case rune <= Rune1Max:
+		return 1;
+	case rune <= Rune2Max:
+		return 2;
+	case rune <= Rune3Max:
+		return 3;
+	case rune <= Rune4Max:
+		return 4;
+	}
+	return -1;
+}
+
+export func EncodeRune(rune int, p *[]byte) int {
+	if rune <= Rune1Max {
+		p[0] = byte(rune);
+		return 1;
+	}
+
+	if rune <= Rune2Max {
+		p[0] = T2 | byte(rune>>6);
+		p[1] = Tx | byte(rune)&Maskx;
+		return 2;
+	}
+
+	if rune > RuneMax {
+		rune = RuneError
+	}
+
+	if rune <= Rune3Max {
+		p[0] = T3 | byte(rune>>12);
+		p[1] = Tx | byte(rune>>6)&Maskx;
+		p[2] = Tx | byte(rune)&Maskx;
+		return 3;
+	}
+
+	p[0] = T4 | byte(rune>>18);
+	p[1] = Tx | byte(rune>>12)&Maskx;
+	p[2] = Tx | byte(rune>>6)&Maskx;
+	p[3] = Tx | byte(rune)&Maskx;
+	return 4;
+}
+
diff --git a/src/lib/utf8_test.go b/src/lib/utf8_test.go
new file mode 100644
index 000000000..550f4ba14
--- /dev/null
+++ b/src/lib/utf8_test.go
@@ -0,0 +1,150 @@
+// 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 utf8
+
+import (
+	"fmt";
+	"syscall";
+	"testing";
+	"utf8";
+)
+
+type Utf8Map struct {
+	rune int;
+	str string;
+}
+
+var utf8map = []Utf8Map {
+	Utf8Map{ 0x0000, "\x00" },
+	Utf8Map{ 0x0001, "\x01" },
+	Utf8Map{ 0x007e, "\x7e" },
+	Utf8Map{ 0x007f, "\x7f" },
+	Utf8Map{ 0x0080, "\xc2\x80" },
+	Utf8Map{ 0x0081, "\xc2\x81" },
+	Utf8Map{ 0x00bf, "\xc2\xbf" },
+	Utf8Map{ 0x00c0, "\xc3\x80" },
+	Utf8Map{ 0x00c1, "\xc3\x81" },
+	Utf8Map{ 0x00c8, "\xc3\x88" },
+	Utf8Map{ 0x00d0, "\xc3\x90" },
+	Utf8Map{ 0x00e0, "\xc3\xa0" },
+	Utf8Map{ 0x00f0, "\xc3\xb0" },
+	Utf8Map{ 0x00f8, "\xc3\xb8" },
+	Utf8Map{ 0x00ff, "\xc3\xbf" },
+	Utf8Map{ 0x0100, "\xc4\x80" },
+	Utf8Map{ 0x07ff, "\xdf\xbf" },
+	Utf8Map{ 0x0800, "\xe0\xa0\x80" },
+	Utf8Map{ 0x0801, "\xe0\xa0\x81" },
+	Utf8Map{ 0xfffe, "\xef\xbf\xbe" },
+	Utf8Map{ 0xffff, "\xef\xbf\xbf" },
+	Utf8Map{ 0x10000, "\xf0\x90\x80\x80" },
+	Utf8Map{ 0x10001, "\xf0\x90\x80\x81" },
+	Utf8Map{ 0x10fffe, "\xf4\x8f\xbf\xbe" },
+	Utf8Map{ 0x10ffff, "\xf4\x8f\xbf\xbf" },
+}
+
+func CEscape(s *[]byte) string {
+	t := "\"";
+	for i := 0; i < len(s); i++ {
+		switch {
+		case s[i] == '\\' || s[i] == '"':
+			t += `\`;
+			t += string(s[i]);
+		case s[i] == '\n':
+			t += `\n`;
+		case s[i] == '\t':
+			t += `\t`;
+		case ' ' <= s[i] && s[i] <= '~':
+			t += string(s[i]);
+		default:
+			t += fmt.sprintf(`\x%02x`, s[i]);
+		}
+	}
+	t += "\"";
+	return t;
+}
+
+func Bytes(s string) *[]byte {
+	b := new([]byte, len(s)+1);
+	if !syscall.StringToBytes(b, s) {
+		panic("StringToBytes failed");
+	}
+	return b[0:len(s)];
+}
+
+export func TestFullRune(t *testing.T) {
+	for i := 0; i < len(utf8map); i++ {
+		m := utf8map[i];
+		b := Bytes(m.str);
+		if !utf8.FullRune(b) {
+			t.Errorf("FullRune(%s) (rune %04x) = false, want true", CEscape(b), m.rune);
+		}
+		if b1 := b[0:len(b)-1]; utf8.FullRune(b1) {
+			t.Errorf("FullRune(%s) = true, want false", CEscape(b1));
+		}
+	}
+}
+
+func EqualBytes(a, b *[]byte) bool {
+	if len(a) != len(b) {
+		return false;
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i] != b[i] {
+			return false;
+		}
+	}
+	return true;
+}
+
+export func TestEncodeRune(t *testing.T) {
+	for i := 0; i < len(utf8map); i++ {
+		m := utf8map[i];
+		b := Bytes(m.str);
+		var buf [10]byte;
+		n := utf8.EncodeRune(m.rune, &buf);
+		b1 := (&buf)[0:n];
+		if !EqualBytes(b, b1) {
+			t.Errorf("EncodeRune(0x%04x) = %s want %s", m.rune, CEscape(b1), CEscape(b));
+		}
+	}
+}
+
+export func TestDecodeRune(t *testing.T) {
+	for i := 0; i < len(utf8map); i++ {
+		m := utf8map[i];
+		b := Bytes(m.str);
+		rune, size := utf8.DecodeRune(b);
+		if rune != m.rune || size != len(b) {
+			t.Errorf("DecodeRune(%s) = 0x%04x, %d want 0x%04x, %d", CEscape(b), rune, size, m.rune, len(b));
+		}
+
+		// there's an extra byte that Bytes left behind - make sure trailing byte works
+		rune, size = utf8.DecodeRune(b[0:cap(b)]);
+		if rune != m.rune || size != len(b) {
+			t.Errorf("DecodeRune(%s) = 0x%04x, %d want 0x%04x, %d", CEscape(b), rune, size, m.rune, len(b));
+		}
+
+		// make sure missing bytes fail
+		rune, size = utf8.DecodeRune(b[0:len(b)-1]);
+		wantsize := 1;
+		if wantsize >= len(b) {
+			wantsize = 0;
+		}
+		if rune != RuneError || size != wantsize {
+			t.Errorf("DecodeRune(%s) = 0x%04x, %d want 0x%04x, %d", CEscape(b[0:len(b)-1]), rune, size, RuneError, wantsize);
+		}
+
+		// make sure bad sequences fail
+		if len(b) == 1 {
+			b[0] = 0x80;
+		} else {
+			b[len(b)-1] = 0x7F;
+		}
+		rune, size = utf8.DecodeRune(b);
+		if rune != RuneError || size != 1 {
+			t.Errorf("DecodeRune(%s) = 0x%04x, %d want 0x%04x, %d", CEscape(b), rune, size, RuneError, 1);
+		}
+	}
+}
diff --git a/src/run.bash b/src/run.bash
index ea06e8c5b..4bba1bf53 100755
--- a/src/run.bash
+++ b/src/run.bash
@@ -32,6 +32,8 @@ maketest \
 # all of these are subtly different
 # from what maketest does.
 
+(xcd lib; make test) || exit $?
+
 (xcd ../usr/gri/pretty
 make clean
 time make