3 files changed, 268 insertions, 0 deletions
diff --git a/src/lib/strings/Makefile b/src/lib/strings/Makefile
new file mode 100644
index 000000000..9372f4d16
--- /dev/null
+++ b/src/lib/strings/Makefile
@@ -0,0 +1,68 @@
+# 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.
+
+# DO NOT EDIT.  Automatically generated by gobuild.
+# gobuild -m >Makefile
+
+D=
+
+O_arm=5
+O_amd64=6
+O_386=8
+OS=568vq
+
+O=$(O_$(GOARCH))
+GC=$(O)g -I_obj
+CC=$(O)c -FVw
+AS=$(O)a
+AR=6ar
+
+default: packages
+
+clean:
+	rm -rf *.[$(OS)] *.a [$(OS)].out _obj
+
+test: packages
+	gotest
+
+coverage: packages
+	gotest
+	6cov -g `pwd` | grep -v '_test\.go:'
+
+%.$O: %.go
+	$(GC) $*.go
+
+%.$O: %.c
+	$(CC) $*.c
+
+%.$O: %.s
+	$(AS) $*.s
+
+O1=\
+	strings.$O\
+
+
+phases: a1
+_obj$D/strings.a: phases
+
+a1: $(O1)
+	$(AR) grc _obj$D/strings.a strings.$O
+	rm -f $(O1)
+
+
+newpkg: clean
+	mkdir -p _obj$D
+	$(AR) grc _obj$D/strings.a
+
+$(O1): newpkg
+$(O2): a1
+
+nuke: clean
+	rm -f $(GOROOT)/pkg$D/strings.a
+
+packages: _obj$D/strings.a
+
+install: packages
+	test -d $(GOROOT)/pkg && mkdir -p $(GOROOT)/pkg$D
+	cp _obj$D/strings.a $(GOROOT)/pkg$D/strings.a
diff --git a/src/lib/strings/strings.go b/src/lib/strings/strings.go
new file mode 100644
index 000000000..33adab249
--- /dev/null
+++ b/src/lib/strings/strings.go
@@ -0,0 +1,119 @@
+// 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.
+
+// A package of simple functions to manipulate strings.
+package strings
+
+import "utf8"
+
+// Explode splits s into an array of UTF-8 sequences, one per Unicode character (still strings).
+// Invalid UTF-8 sequences become correct encodings of U+FFF8.
+func Explode(s string) []string {
+	a := make([]string, utf8.RuneCountInString(s));
+	j := 0;
+	var size, rune int;
+	for i := 0; i < len(a); i++ {
+		rune, size = utf8.DecodeRuneInString(s, j);
+		a[i] = string(rune);
+		j += size;
+	}
+	return a
+}
+
+// Count counts the number of non-overlapping instances of sep in s.
+func Count(s, sep string) int {
+	if sep == "" {
+		return utf8.RuneCountInString(s)+1
+	}
+	c := sep[0];
+	n := 0;
+	for i := 0; i+len(sep) <= len(s); i++ {
+		if s[i] == c && (len(sep) == 1 || s[i:i+len(sep)] == sep) {
+			n++;
+			i += len(sep)-1
+		}
+	}
+	return n
+}
+
+// Index returns the index of the first instance of sep in s, or -1 if sep is not present in s.
+func Index(s, sep string) int {
+	n := len(sep);
+	if n == 0 {
+		return 0
+	}
+	c := sep[0];
+	for i := 0; i+n <= len(s); i++ {
+		if s[i] == c && (n == 1 || s[i:i+n] == sep) {
+			return i
+		}
+	}
+	return -1
+}
+
+// Split returns the array representing the substrings of s separated by string sep. Adjacent
+// occurrences of sep produce empty substrings.  If sep is empty, it is the same as Explode.
+func Split(s, sep string) []string {
+	if sep == "" {
+		return Explode(s)
+	}
+	c := sep[0];
+	start := 0;
+	n := Count(s, sep)+1;
+	a := make([]string, n);
+	na := 0;
+	for i := 0; i+len(sep) <= len(s); i++ {
+		if s[i] == c && (len(sep) == 1 || s[i:i+len(sep)] == sep) {
+			a[na] = s[start:i];
+			na++;
+			start = i+len(sep);
+			i += len(sep)-1
+		}
+	}
+	a[na] = s[start:len(s)];
+	return a
+}
+
+// Join concatenates the elements of a to create a single string.   The separator string
+// sep is placed between elements in the resulting string.
+func Join(a []string, sep string) string {
+	if len(a) == 0 {
+		return ""
+	}
+	if len(a) == 1 {
+		return a[0]
+	}
+	n := len(sep) * (len(a)-1);
+	for i := 0; i < len(a); i++ {
+		n += len(a[i])
+	}
+
+	b := make([]byte, n);
+	bp := 0;
+	for i := 0; i < len(a); i++ {
+		s := a[i];
+		for j := 0; j < len(s); j++ {
+			b[bp] = s[j];
+			bp++
+		}
+		if i + 1 < len(a) {
+			s = sep;
+			for j := 0; j < len(s); j++ {
+				b[bp] = s[j];
+				bp++
+			}
+		}
+	}
+	return string(b)
+}
+
+// HasPrefix tests whether the string s begins with prefix.
+func HasPrefix(s, prefix string) bool {
+	return len(s) >= len(prefix) && s[0:len(prefix)] == prefix
+}
+
+// HasSuffix tests whether the string s ends with suffix.
+func HasSuffix(s, suffix string) bool {
+	return len(s) >= len(suffix) && s[len(s)-len(suffix):len(s)] == suffix
+}
diff --git a/src/lib/strings/strings_test.go b/src/lib/strings/strings_test.go
new file mode 100644
index 000000000..2cbf70b93
--- /dev/null
+++ b/src/lib/strings/strings_test.go
@@ -0,0 +1,81 @@
+// 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 strings
+
+import (
+	"strings";
+	"testing";
+)
+
+func eq(a, b []string) bool {
+	if len(a) != len(b) {
+		return false;
+	}
+	for i := 0; i < len(a); i++ {
+		if a[i] != b[i] {
+			return false;
+		}
+	}
+	return true;
+}
+
+var abcd = "abcd";
+var faces = "☺☻☹";
+var commas = "1,2,3,4";
+var dots = "1....2....3....4";
+
+type ExplodeTest struct {
+	s string;
+	a []string;
+}
+var explodetests = []ExplodeTest {
+	ExplodeTest{ abcd,	[]string{"a", "b", "c", "d"} },
+	ExplodeTest{ faces,	[]string{"☺", "☻", "☹" } },
+}
+func TestExplode(t *testing.T) {
+	for i := 0; i < len(explodetests); i++ {
+		tt := explodetests[i];
+		a := Explode(tt.s);
+		if !eq(a, tt.a) {
+			t.Errorf("Explode(%q) = %v; want %v", tt.s, a, tt.a);
+			continue;
+		}
+		s := Join(a, "");
+		if s != tt.s {
+			t.Errorf(`Join(Explode(%q), "") = %q`, tt.s, s);
+		}
+	}
+}
+
+type SplitTest struct {
+	s string;
+	sep string;
+	a []string;
+}
+var splittests = []SplitTest {
+	SplitTest{ abcd,	"a",	[]string{"", "bcd"} },
+	SplitTest{ abcd,	"z",	[]string{"abcd"} },
+	SplitTest{ abcd,	"",	[]string{"a", "b", "c", "d"} },
+	SplitTest{ commas,	",",	[]string{"1", "2", "3", "4"} },
+	SplitTest{ dots,	"...",	[]string{"1", ".2", ".3", ".4"} },
+	SplitTest{ faces,	"☹",	[]string{"☺☻", ""} },
+	SplitTest{ faces,	"~",	[]string{faces} },
+	SplitTest{ faces,	"",	[]string{"☺", "☻", "☹"} },
+}
+func TestSplit(t *testing.T) {
+	for i := 0; i < len(splittests); i++ {
+		tt := splittests[i];
+		a := Split(tt.s, tt.sep);
+		if !eq(a, tt.a) {
+			t.Errorf("Split(%q, %q) = %v; want %v", tt.s, tt.sep, a, tt.a);
+			continue;
+		}
+		s := Join(a, tt.sep);
+		if s != tt.s {
+			t.Errorf("Join(Split(%q, %q), %q) = %q", tt.s, tt.sep, tt.sep, s);
+		}
+	}
+}
+