Imported Upstream version 2011.01.12upstream/2011.01.12

3 files changed, 358 insertions, 283 deletions

diff --git a/src/pkg/strings/Makefile b/src/pkg/strings/Makefile
index 9bae470e9..c1be58243 100644
--- a/src/pkg/strings/Makefile
+++ b/src/pkg/strings/Makefile
@@ -2,7 +2,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
-include ../../Make.$(GOARCH)
+include ../../Make.inc
 
 TARG=strings
 GOFILES=\
diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go
index 5d3d61e19..98a0d5731 100644
--- a/src/pkg/strings/strings.go
+++ b/src/pkg/strings/strings.go
@@ -28,8 +28,10 @@ func explode(s string, n int) []string {
 		a[i] = string(rune)
 		cur += size
 	}
-	// add the rest
-	a[i] = s[cur:]
+	// add the rest, if there is any
+	if cur < len(s) {
+		a[i] = s[cur:]
+	}
 	return a
 }
 
@@ -59,6 +61,11 @@ func Count(s, sep string) int {
 	return n
 }
 
+// Contains returns true if substr is within s.
+func Contains(s, substr string) bool {
+	return Index(s, substr) != -1
+}
+
 // 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)
@@ -135,6 +142,24 @@ func IndexAny(s, chars string) int {
 	return -1
 }
 
+// LastIndexAny returns the index of the last instance of any Unicode code
+// point from chars in s, or -1 if no Unicode code point from chars is
+// present in s.
+func LastIndexAny(s, chars string) int {
+	if len(chars) > 0 {
+		for i := len(s); i > 0; {
+			rune, size := utf8.DecodeLastRuneInString(s[0:i])
+			i -= size
+			for _, m := range chars {
+				if rune == m {
+					return i
+				}
+			}
+		}
+	}
+	return -1
+}
+
 // Generic split: splits after each instance of sep,
 // including sepSave bytes of sep in the subarrays.
 func genSplit(s, sep string, sepSave, n int) []string {
@@ -163,16 +188,22 @@ func genSplit(s, sep string, sepSave, n int) []string {
 	return a[0 : na+1]
 }
 
-// Split splits the string s around each instance of sep, returning an array of substrings of s.
-// If sep is empty, Split splits s after each UTF-8 sequence.
-// If n >= 0, Split splits s into at most n substrings; the last substring will be the unsplit remainder.
-// Thus if n == 0, the result will be nil.
+// Split slices s into substrings separated by sep and returns a slice of
+// the substrings between those separators.
+// If sep is empty, Split splits after each UTF-8 sequence.
+// The count determines the number of substrings to return:
+//   n > 0: at most n substrings; the last substring will be the unsplit remainder.
+//   n == 0: the result is nil (zero substrings)
+//   n < 0: all substrings
 func Split(s, sep string, n int) []string { return genSplit(s, sep, 0, n) }
 
-// SplitAfter splits the string s after each instance of sep, returning an array of substrings of s.
-// If sep is empty, SplitAfter splits s after each UTF-8 sequence.
-// If n >= 0, SplitAfter splits s into at most n substrings; the last substring will be the unsplit remainder.
-// Thus if n == 0, the result will be nil.
+// SplitAfter slices s into substrings after each instance of sep and
+// returns a slice of those substrings.
+// If sep is empty, Split splits after each UTF-8 sequence.
+// The count determines the number of substrings to return:
+//   n > 0: at most n substrings; the last substring will be the unsplit remainder.
+//   n == 0: the result is nil (zero substrings)
+//   n < 0: all substrings
 func SplitAfter(s, sep string, n int) []string {
 	return genSplit(s, sep, len(sep), n)
 }
@@ -183,9 +214,9 @@ func Fields(s string) []string {
 	return FieldsFunc(s, unicode.IsSpace)
 }
 
-// FieldsFunc splits the string s at each run of Unicode code points c satifying f(c)
-// and returns an array of slices of s. If no code points in s satisfy f(c), an empty slice
-// is returned.
+// FieldsFunc splits the string s at each run of Unicode code points c satisfying f(c)
+// and returns an array of slices of s. If all code points in s satisfy f(c) or the
+// string is empty, an empty slice is returned.
 func FieldsFunc(s string, f func(int) bool) []string {
 	// First count the fields.
 	n := 0
@@ -286,7 +317,7 @@ func Map(mapping func(rune int) int, s string) string {
 				copy(nb, b[0:nbytes])
 				b = nb
 			}
-			nbytes += utf8.EncodeRune(rune, b[nbytes:maxbytes])
+			nbytes += utf8.EncodeRune(b[nbytes:maxbytes], rune)
 		}
 	}
 	return string(b[0:nbytes])
@@ -333,6 +364,52 @@ func ToTitleSpecial(_case unicode.SpecialCase, s string) string {
 	return Map(func(r int) int { return _case.ToTitle(r) }, s)
 }
 
+// isSeparator reports whether the rune could mark a word boundary.
+// TODO: update when package unicode captures more of the properties.
+func isSeparator(rune int) bool {
+	// ASCII alphanumerics and underscore are not separators
+	if rune <= 0x7F {
+		switch {
+		case '0' <= rune && rune <= '9':
+			return false
+		case 'a' <= rune && rune <= 'z':
+			return false
+		case 'A' <= rune && rune <= 'Z':
+			return false
+		case rune == '_':
+			return false
+		}
+		return true
+	}
+	// Letters and digits are not separators
+	if unicode.IsLetter(rune) || unicode.IsDigit(rune) {
+		return false
+	}
+	// Otherwise, all we can do for now is treat spaces as separators.
+	return unicode.IsSpace(rune)
+}
+
+// BUG(r): The rule Title uses for word boundaries does not handle Unicode punctuation properly.
+
+// Title returns a copy of the string s with all Unicode letters that begin words
+// mapped to their title case.
+func Title(s string) string {
+	// Use a closure here to remember state.
+	// Hackish but effective. Depends on Map scanning in order and calling
+	// the closure once per rune.
+	prev := ' '
+	return Map(
+		func(r int) int {
+			if isSeparator(prev) {
+				prev = r
+				return unicode.ToTitle(r)
+			}
+			prev = r
+			return r
+		},
+		s)
+}
+
 // TrimLeftFunc returns a slice of the string s with all leading
 // Unicode code points c satisfying f(c) removed.
 func TrimLeftFunc(s string, f func(r int) bool) string {
@@ -376,8 +453,7 @@ func LastIndexFunc(s string, f func(r int) bool) int {
 
 // indexFunc is the same as IndexFunc except that if
 // truth==false, the sense of the predicate function is
-// inverted. We could use IndexFunc directly, but this
-// way saves a closure allocation.
+// inverted.
 func indexFunc(s string, f func(r int) bool, truth bool) int {
 	start := 0
 	for start < len(s) {
@@ -396,37 +472,14 @@ func indexFunc(s string, f func(r int) bool, truth bool) int {
 
 // lastIndexFunc is the same as LastIndexFunc except that if
 // truth==false, the sense of the predicate function is
-// inverted. We could use IndexFunc directly, but this
-// way saves a closure allocation.
+// inverted.
 func lastIndexFunc(s string, f func(r int) bool, truth bool) int {
-	end := len(s)
-	for end > 0 {
-		start := end - 1
-		rune := int(s[start])
-		if rune >= utf8.RuneSelf {
-			// Back up & look for beginning of rune. Mustn't pass start.
-			for start--; start >= 0; start-- {
-				if utf8.RuneStart(s[start]) {
-					break
-				}
-			}
-			if start < 0 {
-				return -1
-			}
-			var wid int
-			rune, wid = utf8.DecodeRuneInString(s[start:end])
-
-			// If we've decoded fewer bytes than we expected,
-			// we've got some invalid UTF-8, so make sure we return
-			// the last possible index in s.
-			if start+wid < end && f(utf8.RuneError) == truth {
-				return end - 1
-			}
-		}
+	for i := len(s); i > 0; {
+		rune, size := utf8.DecodeLastRuneInString(s[0:i])
+		i -= size
 		if f(rune) == truth {
-			return start
+			return i
 		}
-		end = start
 	}
 	return -1
 }
@@ -497,21 +550,10 @@ func Replace(s, old, new string, n int) string {
 		} else {
 			j += Index(s[start:], old)
 		}
-		w += copyString(t[w:], s[start:j])
-		w += copyString(t[w:], new)
+		w += copy(t[w:], s[start:j])
+		w += copy(t[w:], new)
 		start = j + len(old)
 	}
-	w += copyString(t[w:], s[start:])
+	w += copy(t[w:], s[start:])
 	return string(t[0:w])
 }
-
-func copyString(dst []byte, src string) int {
-	n := len(dst)
-	if n > len(src) {
-		n = len(src)
-	}
-	for i := 0; i < n; i++ {
-		dst[i] = src[i]
-	}
-	return n
-}
diff --git a/src/pkg/strings/strings_test.go b/src/pkg/strings/strings_test.go
index 06f1f1de1..734fdd33d 100644
--- a/src/pkg/strings/strings_test.go
+++ b/src/pkg/strings/strings_test.go
@@ -36,55 +36,68 @@ type IndexTest struct {
 }
 
 var indexTests = []IndexTest{
-	IndexTest{"", "", 0},
-	IndexTest{"", "a", -1},
-	IndexTest{"", "foo", -1},
-	IndexTest{"fo", "foo", -1},
-	IndexTest{"foo", "foo", 0},
-	IndexTest{"oofofoofooo", "f", 2},
-	IndexTest{"oofofoofooo", "foo", 4},
-	IndexTest{"barfoobarfoo", "foo", 3},
-	IndexTest{"foo", "", 0},
-	IndexTest{"foo", "o", 1},
-	IndexTest{"abcABCabc", "A", 3},
+	{"", "", 0},
+	{"", "a", -1},
+	{"", "foo", -1},
+	{"fo", "foo", -1},
+	{"foo", "foo", 0},
+	{"oofofoofooo", "f", 2},
+	{"oofofoofooo", "foo", 4},
+	{"barfoobarfoo", "foo", 3},
+	{"foo", "", 0},
+	{"foo", "o", 1},
+	{"abcABCabc", "A", 3},
 	// cases with one byte strings - test special case in Index()
-	IndexTest{"", "a", -1},
-	IndexTest{"x", "a", -1},
-	IndexTest{"x", "x", 0},
-	IndexTest{"abc", "a", 0},
-	IndexTest{"abc", "b", 1},
-	IndexTest{"abc", "c", 2},
-	IndexTest{"abc", "x", -1},
+	{"", "a", -1},
+	{"x", "a", -1},
+	{"x", "x", 0},
+	{"abc", "a", 0},
+	{"abc", "b", 1},
+	{"abc", "c", 2},
+	{"abc", "x", -1},
 }
 
 var lastIndexTests = []IndexTest{
-	IndexTest{"", "", 0},
-	IndexTest{"", "a", -1},
-	IndexTest{"", "foo", -1},
-	IndexTest{"fo", "foo", -1},
-	IndexTest{"foo", "foo", 0},
-	IndexTest{"foo", "f", 0},
-	IndexTest{"oofofoofooo", "f", 7},
-	IndexTest{"oofofoofooo", "foo", 7},
-	IndexTest{"barfoobarfoo", "foo", 9},
-	IndexTest{"foo", "", 3},
-	IndexTest{"foo", "o", 2},
-	IndexTest{"abcABCabc", "A", 3},
-	IndexTest{"abcABCabc", "a", 6},
+	{"", "", 0},
+	{"", "a", -1},
+	{"", "foo", -1},
+	{"fo", "foo", -1},
+	{"foo", "foo", 0},
+	{"foo", "f", 0},
+	{"oofofoofooo", "f", 7},
+	{"oofofoofooo", "foo", 7},
+	{"barfoobarfoo", "foo", 9},
+	{"foo", "", 3},
+	{"foo", "o", 2},
+	{"abcABCabc", "A", 3},
+	{"abcABCabc", "a", 6},
 }
 
 var indexAnyTests = []IndexTest{
-	IndexTest{"", "", -1},
-	IndexTest{"", "a", -1},
-	IndexTest{"", "abc", -1},
-	IndexTest{"a", "", -1},
-	IndexTest{"a", "a", 0},
-	IndexTest{"aaa", "a", 0},
-	IndexTest{"abc", "xyz", -1},
-	IndexTest{"abc", "xcz", 2},
-	IndexTest{"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
-	IndexTest{"aRegExp*", ".(|)*+?^$[]", 7},
-	IndexTest{dots + dots + dots, " ", -1},
+	{"", "", -1},
+	{"", "a", -1},
+	{"", "abc", -1},
+	{"a", "", -1},
+	{"a", "a", 0},
+	{"aaa", "a", 0},
+	{"abc", "xyz", -1},
+	{"abc", "xcz", 2},
+	{"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
+	{"aRegExp*", ".(|)*+?^$[]", 7},
+	{dots + dots + dots, " ", -1},
+}
+var lastIndexAnyTests = []IndexTest{
+	{"", "", -1},
+	{"", "a", -1},
+	{"", "abc", -1},
+	{"a", "", -1},
+	{"a", "a", 0},
+	{"aaa", "a", 2},
+	{"abc", "xyz", -1},
+	{"abc", "ab", 1},
+	{"a☺b☻c☹d", "uvw☻xyz", 2 + len("☺")},
+	{"a.RegExp*", ".(|)*+?^$[]", 8},
+	{dots + dots + dots, " ", -1},
 }
 
 // Execute f on each test case.  funcName should be the name of f; it's used
@@ -98,9 +111,10 @@ func runIndexTests(t *testing.T, f func(s, sep string) int, funcName string, tes
 	}
 }
 
-func TestIndex(t *testing.T)     { runIndexTests(t, Index, "Index", indexTests) }
-func TestLastIndex(t *testing.T) { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
-func TestIndexAny(t *testing.T)  { runIndexTests(t, IndexAny, "IndexAny", indexAnyTests) }
+func TestIndex(t *testing.T)        { runIndexTests(t, Index, "Index", indexTests) }
+func TestLastIndex(t *testing.T)    { runIndexTests(t, LastIndex, "LastIndex", lastIndexTests) }
+func TestIndexAny(t *testing.T)     { runIndexTests(t, IndexAny, "IndexAny", indexAnyTests) }
+func TestLastIndexAny(t *testing.T) { runIndexTests(t, LastIndexAny, "LastIndexAny", lastIndexAnyTests) }
 
 type ExplodeTest struct {
 	s string
@@ -109,9 +123,10 @@ type ExplodeTest struct {
 }
 
 var explodetests = []ExplodeTest{
-	ExplodeTest{abcd, 4, []string{"a", "b", "c", "d"}},
-	ExplodeTest{faces, 3, []string{"☺", "☻", "☹"}},
-	ExplodeTest{abcd, 2, []string{"a", "bcd"}},
+	{"", -1, []string{}},
+	{abcd, 4, []string{"a", "b", "c", "d"}},
+	{faces, 3, []string{"☺", "☻", "☹"}},
+	{abcd, 2, []string{"a", "bcd"}},
 }
 
 func TestExplode(t *testing.T) {
@@ -136,19 +151,19 @@ type SplitTest struct {
 }
 
 var splittests = []SplitTest{
-	SplitTest{abcd, "a", 0, nil},
-	SplitTest{abcd, "a", -1, []string{"", "bcd"}},
-	SplitTest{abcd, "z", -1, []string{"abcd"}},
-	SplitTest{abcd, "", -1, []string{"a", "b", "c", "d"}},
-	SplitTest{commas, ",", -1, []string{"1", "2", "3", "4"}},
-	SplitTest{dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
-	SplitTest{faces, "☹", -1, []string{"☺☻", ""}},
-	SplitTest{faces, "~", -1, []string{faces}},
-	SplitTest{faces, "", -1, []string{"☺", "☻", "☹"}},
-	SplitTest{"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
-	SplitTest{"1 2", " ", 3, []string{"1", "2"}},
-	SplitTest{"123", "", 2, []string{"1", "23"}},
-	SplitTest{"123", "", 17, []string{"1", "2", "3"}},
+	{abcd, "a", 0, nil},
+	{abcd, "a", -1, []string{"", "bcd"}},
+	{abcd, "z", -1, []string{"abcd"}},
+	{abcd, "", -1, []string{"a", "b", "c", "d"}},
+	{commas, ",", -1, []string{"1", "2", "3", "4"}},
+	{dots, "...", -1, []string{"1", ".2", ".3", ".4"}},
+	{faces, "☹", -1, []string{"☺☻", ""}},
+	{faces, "~", -1, []string{faces}},
+	{faces, "", -1, []string{"☺", "☻", "☹"}},
+	{"1 2 3 4", " ", 3, []string{"1", "2", "3 4"}},
+	{"1 2", " ", 3, []string{"1", "2"}},
+	{"123", "", 2, []string{"1", "23"}},
+	{"123", "", 17, []string{"1", "2", "3"}},
 }
 
 func TestSplit(t *testing.T) {
@@ -169,19 +184,19 @@ func TestSplit(t *testing.T) {
 }
 
 var splitaftertests = []SplitTest{
-	SplitTest{abcd, "a", -1, []string{"a", "bcd"}},
-	SplitTest{abcd, "z", -1, []string{"abcd"}},
-	SplitTest{abcd, "", -1, []string{"a", "b", "c", "d"}},
-	SplitTest{commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
-	SplitTest{dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
-	SplitTest{faces, "☹", -1, []string{"☺☻☹", ""}},
-	SplitTest{faces, "~", -1, []string{faces}},
-	SplitTest{faces, "", -1, []string{"☺", "☻", "☹"}},
-	SplitTest{"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
-	SplitTest{"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
-	SplitTest{"1 2", " ", 3, []string{"1 ", "2"}},
-	SplitTest{"123", "", 2, []string{"1", "23"}},
-	SplitTest{"123", "", 17, []string{"1", "2", "3"}},
+	{abcd, "a", -1, []string{"a", "bcd"}},
+	{abcd, "z", -1, []string{"abcd"}},
+	{abcd, "", -1, []string{"a", "b", "c", "d"}},
+	{commas, ",", -1, []string{"1,", "2,", "3,", "4"}},
+	{dots, "...", -1, []string{"1...", ".2...", ".3...", ".4"}},
+	{faces, "☹", -1, []string{"☺☻☹", ""}},
+	{faces, "~", -1, []string{faces}},
+	{faces, "", -1, []string{"☺", "☻", "☹"}},
+	{"1 2 3 4", " ", 3, []string{"1 ", "2 ", "3 4"}},
+	{"1 2 3", " ", 3, []string{"1 ", "2 ", "3"}},
+	{"1 2", " ", 3, []string{"1 ", "2"}},
+	{"123", "", 2, []string{"1", "23"}},
+	{"123", "", 17, []string{"1", "2", "3"}},
 }
 
 func TestSplitAfter(t *testing.T) {
@@ -204,17 +219,17 @@ type FieldsTest struct {
 }
 
 var fieldstests = []FieldsTest{
-	FieldsTest{"", []string{}},
-	FieldsTest{" ", []string{}},
-	FieldsTest{" \t ", []string{}},
-	FieldsTest{"  abc  ", []string{"abc"}},
-	FieldsTest{"1 2 3 4", []string{"1", "2", "3", "4"}},
-	FieldsTest{"1  2  3  4", []string{"1", "2", "3", "4"}},
-	FieldsTest{"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
-	FieldsTest{"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
-	FieldsTest{"\u2000\u2001\u2002", []string{}},
-	FieldsTest{"\n™\t™\n", []string{"™", "™"}},
-	FieldsTest{faces, []string{faces}},
+	{"", []string{}},
+	{" ", []string{}},
+	{" \t ", []string{}},
+	{"  abc  ", []string{"abc"}},
+	{"1 2 3 4", []string{"1", "2", "3", "4"}},
+	{"1  2  3  4", []string{"1", "2", "3", "4"}},
+	{"1\t\t2\t\t3\t4", []string{"1", "2", "3", "4"}},
+	{"1\u20002\u20013\u20024", []string{"1", "2", "3", "4"}},
+	{"\u2000\u2001\u2002", []string{}},
+	{"\n™\t™\n", []string{"™", "™"}},
+	{faces, []string{faces}},
 }
 
 func TestFields(t *testing.T) {
@@ -230,10 +245,10 @@ func TestFields(t *testing.T) {
 func TestFieldsFunc(t *testing.T) {
 	pred := func(c int) bool { return c == 'X' }
 	var fieldsFuncTests = []FieldsTest{
-		FieldsTest{"", []string{}},
-		FieldsTest{"XX", []string{}},
-		FieldsTest{"XXhiXXX", []string{"hi"}},
-		FieldsTest{"aXXbXXXcX", []string{"a", "b", "c"}},
+		{"", []string{}},
+		{"XX", []string{}},
+		{"XXhiXXX", []string{"hi"}},
+		{"aXXbXXXcX", []string{"a", "b", "c"}},
 	}
 	for _, tt := range fieldsFuncTests {
 		a := FieldsFunc(tt.s, pred)
@@ -261,40 +276,40 @@ func runStringTests(t *testing.T, f func(string) string, funcName string, testCa
 }
 
 var upperTests = []StringTest{
-	StringTest{"", ""},
-	StringTest{"abc", "ABC"},
-	StringTest{"AbC123", "ABC123"},
-	StringTest{"azAZ09_", "AZAZ09_"},
-	StringTest{"\u0250\u0250\u0250\u0250\u0250", "\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F"}, // grows one byte per char
+	{"", ""},
+	{"abc", "ABC"},
+	{"AbC123", "ABC123"},
+	{"azAZ09_", "AZAZ09_"},
+	{"\u0250\u0250\u0250\u0250\u0250", "\u2C6F\u2C6F\u2C6F\u2C6F\u2C6F"}, // grows one byte per char
 }
 
 var lowerTests = []StringTest{
-	StringTest{"", ""},
-	StringTest{"abc", "abc"},
-	StringTest{"AbC123", "abc123"},
-	StringTest{"azAZ09_", "azaz09_"},
-	StringTest{"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", "\u0251\u0251\u0251\u0251\u0251"}, // shrinks one byte per char
+	{"", ""},
+	{"abc", "abc"},
+	{"AbC123", "abc123"},
+	{"azAZ09_", "azaz09_"},
+	{"\u2C6D\u2C6D\u2C6D\u2C6D\u2C6D", "\u0251\u0251\u0251\u0251\u0251"}, // shrinks one byte per char
 }
 
 const space = "\t\v\r\f\n\u0085\u00a0\u2000\u3000"
 
 var trimSpaceTests = []StringTest{
-	StringTest{"", ""},
-	StringTest{"abc", "abc"},
-	StringTest{space + "abc" + space, "abc"},
-	StringTest{" ", ""},
-	StringTest{" \t\r\n \t\t\r\r\n\n ", ""},
-	StringTest{" \t\r\n x\t\t\r\r\n\n ", "x"},
-	StringTest{" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", "x\t\t\r\r\ny"},
-	StringTest{"1 \t\r\n2", "1 \t\r\n2"},
-	StringTest{" x\x80", "x\x80"},
-	StringTest{" x\xc0", "x\xc0"},
-	StringTest{"x \xc0\xc0 ", "x \xc0\xc0"},
-	StringTest{"x \xc0", "x \xc0"},
-	StringTest{"x \xc0 ", "x \xc0"},
-	StringTest{"x \xc0\xc0 ", "x \xc0\xc0"},
-	StringTest{"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
-	StringTest{"x ☺ ", "x ☺"},
+	{"", ""},
+	{"abc", "abc"},
+	{space + "abc" + space, "abc"},
+	{" ", ""},
+	{" \t\r\n \t\t\r\r\n\n ", ""},
+	{" \t\r\n x\t\t\r\r\n\n ", "x"},
+	{" \u2000\t\r\n x\t\t\r\r\ny\n \u3000", "x\t\t\r\r\ny"},
+	{"1 \t\r\n2", "1 \t\r\n2"},
+	{" x\x80", "x\x80"},
+	{" x\xc0", "x\xc0"},
+	{"x \xc0\xc0 ", "x \xc0\xc0"},
+	{"x \xc0", "x \xc0"},
+	{"x \xc0 ", "x \xc0"},
+	{"x \xc0\xc0 ", "x \xc0\xc0"},
+	{"x ☺\xc0\xc0 ", "x ☺\xc0\xc0"},
+	{"x ☺ ", "x ☺"},
 }
 
 func tenRunes(rune int) string {
@@ -397,48 +412,29 @@ type TrimTest struct {
 }
 
 var trimTests = []TrimTest{
-	TrimTest{Trim, "abba", "a", "bb"},
-	TrimTest{Trim, "abba", "ab", ""},
-	TrimTest{TrimLeft, "abba", "ab", ""},
-	TrimTest{TrimRight, "abba", "ab", ""},
-	TrimTest{TrimLeft, "abba", "a", "bba"},
-	TrimTest{TrimRight, "abba", "a", "abb"},
-	TrimTest{Trim, "<tag>", "<>", "tag"},
-	TrimTest{Trim, "* listitem", " *", "listitem"},
-	TrimTest{Trim, `"quote"`, `"`, "quote"},
-	TrimTest{Trim, "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
+	{Trim, "abba", "a", "bb"},
+	{Trim, "abba", "ab", ""},
+	{TrimLeft, "abba", "ab", ""},
+	{TrimRight, "abba", "ab", ""},
+	{TrimLeft, "abba", "a", "bba"},
+	{TrimRight, "abba", "a", "abb"},
+	{Trim, "<tag>", "<>", "tag"},
+	{Trim, "* listitem", " *", "listitem"},
+	{Trim, `"quote"`, `"`, "quote"},
+	{Trim, "\u2C6F\u2C6F\u0250\u0250\u2C6F\u2C6F", "\u2C6F", "\u0250\u0250"},
 	//empty string tests
-	TrimTest{Trim, "abba", "", "abba"},
-	TrimTest{Trim, "", "123", ""},
-	TrimTest{Trim, "", "", ""},
-	TrimTest{TrimLeft, "abba", "", "abba"},
-	TrimTest{TrimLeft, "", "123", ""},
-	TrimTest{TrimLeft, "", "", ""},
-	TrimTest{TrimRight, "abba", "", "abba"},
-	TrimTest{TrimRight, "", "123", ""},
-	TrimTest{TrimRight, "", "", ""},
-	TrimTest{TrimRight, "☺\xc0", "☺", "☺\xc0"},
-}
-
-// naiveTrimRight implements a version of TrimRight
-// by scanning forwards from the start of s.
-func naiveTrimRight(s string, cutset string) string {
-	i := -1
-	for j, r := range s {
-		if IndexRune(cutset, r) == -1 {
-			i = j
-		}
-	}
-	if i >= 0 && s[i] >= utf8.RuneSelf {
-		_, wid := utf8.DecodeRuneInString(s[i:])
-		i += wid
-	} else {
-		i++
-	}
-	return s[0:i]
+	{Trim, "abba", "", "abba"},
+	{Trim, "", "123", ""},
+	{Trim, "", "", ""},
+	{TrimLeft, "abba", "", "abba"},
+	{TrimLeft, "", "123", ""},
+	{TrimLeft, "", "", ""},
+	{TrimRight, "abba", "", "abba"},
+	{TrimRight, "", "123", ""},
+	{TrimRight, "", "", ""},
+	{TrimRight, "☺\xc0", "☺", "☺\xc0"},
 }
 
-
 func TestTrim(t *testing.T) {
 	for _, tc := range trimTests {
 		actual := tc.f(tc.in, tc.cutset)
@@ -456,16 +452,14 @@ func TestTrim(t *testing.T) {
 		if actual != tc.out {
 			t.Errorf("%s(%q, %q) = %q; want %q", name, tc.in, tc.cutset, actual, tc.out)
 		}
-		// test equivalence of TrimRight to naive version
-		if tc.f == TrimRight {
-			naive := naiveTrimRight(tc.in, tc.cutset)
-			if naive != actual {
-				t.Errorf("TrimRight(%q, %q) = %q, want %q", tc.in, tc.cutset, actual, naive)
-			}
-		}
 	}
 }
 
+type predicate struct {
+	f    func(r int) bool
+	name string
+}
+
 var isSpace = predicate{unicode.IsSpace, "IsSpace"}
 var isDigit = predicate{unicode.IsDigit, "IsDigit"}
 var isUpper = predicate{unicode.IsUpper, "IsUpper"}
@@ -476,11 +470,6 @@ var isValidRune = predicate{
 	"IsValidRune",
 }
 
-type predicate struct {
-	f    func(r int) bool
-	name string
-}
-
 type TrimFuncTest struct {
 	f       predicate
 	in, out string
@@ -496,13 +485,13 @@ func not(p predicate) predicate {
 }
 
 var trimFuncTests = []TrimFuncTest{
-	TrimFuncTest{isSpace, space + " hello " + space, "hello"},
-	TrimFuncTest{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51", "hello"},
-	TrimFuncTest{isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", "hello"},
-	TrimFuncTest{not(isSpace), "hello" + space + "hello", space},
-	TrimFuncTest{not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo", "\u0e50\u0e521234\u0e50\u0e51"},
-	TrimFuncTest{isValidRune, "ab\xc0a\xc0cd", "\xc0a\xc0"},
-	TrimFuncTest{not(isValidRune), "\xc0a\xc0", "a"},
+	{isSpace, space + " hello " + space, "hello"},
+	{isDigit, "\u0e50\u0e5212hello34\u0e50\u0e51", "hello"},
+	{isUpper, "\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", "hello"},
+	{not(isSpace), "hello" + space + "hello", space},
+	{not(isDigit), "hello\u0e50\u0e521234\u0e50\u0e51helo", "\u0e50\u0e521234\u0e50\u0e51"},
+	{isValidRune, "ab\xc0a\xc0cd", "\xc0a\xc0"},
+	{not(isValidRune), "\xc0a\xc0", "a"},
 }
 
 func TestTrimFunc(t *testing.T) {
@@ -521,24 +510,25 @@ type IndexFuncTest struct {
 }
 
 var indexFuncTests = []IndexFuncTest{
-	IndexFuncTest{"", isValidRune, -1, -1},
-	IndexFuncTest{"abc", isDigit, -1, -1},
-	IndexFuncTest{"0123", isDigit, 0, 3},
-	IndexFuncTest{"a1b", isDigit, 1, 1},
-	IndexFuncTest{space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
-	IndexFuncTest{"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
-	IndexFuncTest{"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
-	IndexFuncTest{"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},
-
-	// broken unicode tests
-	IndexFuncTest{"\x801", isDigit, 1, 1},
-	IndexFuncTest{"\x80abc", isDigit, -1, -1},
-	IndexFuncTest{"\xc0a\xc0", isValidRune, 1, 1},
-	IndexFuncTest{"\xc0a\xc0", not(isValidRune), 0, 2},
-	IndexFuncTest{"\xc0☺\xc0", not(isValidRune), 0, 4},
-	IndexFuncTest{"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
-	IndexFuncTest{"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
-	IndexFuncTest{"a\xe0\x80cd", not(isValidRune), 1, 2},
+	{"", isValidRune, -1, -1},
+	{"abc", isDigit, -1, -1},
+	{"0123", isDigit, 0, 3},
+	{"a1b", isDigit, 1, 1},
+	{space, isSpace, 0, len(space) - 3}, // last rune in space is 3 bytes
+	{"\u0e50\u0e5212hello34\u0e50\u0e51", isDigit, 0, 18},
+	{"\u2C6F\u2C6F\u2C6F\u2C6FABCDhelloEF\u2C6F\u2C6FGH\u2C6F\u2C6F", isUpper, 0, 34},
+	{"12\u0e50\u0e52hello34\u0e50\u0e51", not(isDigit), 8, 12},
+
+	// tests of invalid UTF-8
+	{"\x801", isDigit, 1, 1},
+	{"\x80abc", isDigit, -1, -1},
+	{"\xc0a\xc0", isValidRune, 1, 1},
+	{"\xc0a\xc0", not(isValidRune), 0, 2},
+	{"\xc0☺\xc0", not(isValidRune), 0, 4},
+	{"\xc0☺\xc0\xc0", not(isValidRune), 0, 5},
+	{"ab\xc0a\xc0cd", not(isValidRune), 2, 4},
+	{"a\xe0\x80cd", not(isValidRune), 1, 2},
+	{"\x80\x80\x80\x80", not(isValidRune), 0, 3},
 }
 
 func TestIndexFunc(t *testing.T) {
@@ -619,13 +609,13 @@ type RepeatTest struct {
 }
 
 var RepeatTests = []RepeatTest{
-	RepeatTest{"", "", 0},
-	RepeatTest{"", "", 1},
-	RepeatTest{"", "", 2},
-	RepeatTest{"-", "", 0},
-	RepeatTest{"-", "-", 1},
-	RepeatTest{"-", "----------", 10},
-	RepeatTest{"abc ", "abc abc abc ", 3},
+	{"", "", 0},
+	{"", "", 1},
+	{"", "", 2},
+	{"-", "", 0},
+	{"-", "-", 1},
+	{"-", "----------", 10},
+	{"abc ", "abc abc abc ", 3},
 }
 
 func TestRepeat(t *testing.T) {
@@ -657,13 +647,13 @@ type RunesTest struct {
 }
 
 var RunesTests = []RunesTest{
-	RunesTest{"", []int{}, false},
-	RunesTest{" ", []int{32}, false},
-	RunesTest{"ABC", []int{65, 66, 67}, false},
-	RunesTest{"abc", []int{97, 98, 99}, false},
-	RunesTest{"\u65e5\u672c\u8a9e", []int{26085, 26412, 35486}, false},
-	RunesTest{"ab\x80c", []int{97, 98, 0xFFFD, 99}, true},
-	RunesTest{"ab\xc0c", []int{97, 98, 0xFFFD, 99}, true},
+	{"", []int{}, false},
+	{" ", []int{32}, false},
+	{"ABC", []int{65, 66, 67}, false},
+	{"abc", []int{97, 98, 99}, false},
+	{"\u65e5\u672c\u8a9e", []int{26085, 26412, 35486}, false},
+	{"ab\x80c", []int{97, 98, 0xFFFD, 99}, true},
+	{"ab\xc0c", []int{97, 98, 0xFFFD, 99}, true},
 }
 
 func TestRunes(t *testing.T) {
@@ -713,25 +703,25 @@ type ReplaceTest struct {
 }
 
 var ReplaceTests = []ReplaceTest{
-	ReplaceTest{"hello", "l", "L", 0, "hello"},
-	ReplaceTest{"hello", "l", "L", -1, "heLLo"},
-	ReplaceTest{"hello", "x", "X", -1, "hello"},
-	ReplaceTest{"", "x", "X", -1, ""},
-	ReplaceTest{"radar", "r", "<r>", -1, "<r>ada<r>"},
-	ReplaceTest{"", "", "<>", -1, "<>"},
-	ReplaceTest{"banana", "a", "<>", -1, "b<>n<>n<>"},
-	ReplaceTest{"banana", "a", "<>", 1, "b<>nana"},
-	ReplaceTest{"banana", "a", "<>", 1000, "b<>n<>n<>"},
-	ReplaceTest{"banana", "an", "<>", -1, "b<><>a"},
-	ReplaceTest{"banana", "ana", "<>", -1, "b<>na"},
-	ReplaceTest{"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
-	ReplaceTest{"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
-	ReplaceTest{"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
-	ReplaceTest{"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
-	ReplaceTest{"banana", "", "<>", 1, "<>banana"},
-	ReplaceTest{"banana", "a", "a", -1, "banana"},
-	ReplaceTest{"banana", "a", "a", 1, "banana"},
-	ReplaceTest{"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
+	{"hello", "l", "L", 0, "hello"},
+	{"hello", "l", "L", -1, "heLLo"},
+	{"hello", "x", "X", -1, "hello"},
+	{"", "x", "X", -1, ""},
+	{"radar", "r", "<r>", -1, "<r>ada<r>"},
+	{"", "", "<>", -1, "<>"},
+	{"banana", "a", "<>", -1, "b<>n<>n<>"},
+	{"banana", "a", "<>", 1, "b<>nana"},
+	{"banana", "a", "<>", 1000, "b<>n<>n<>"},
+	{"banana", "an", "<>", -1, "b<><>a"},
+	{"banana", "ana", "<>", -1, "b<>na"},
+	{"banana", "", "<>", -1, "<>b<>a<>n<>a<>n<>a<>"},
+	{"banana", "", "<>", 10, "<>b<>a<>n<>a<>n<>a<>"},
+	{"banana", "", "<>", 6, "<>b<>a<>n<>a<>n<>a"},
+	{"banana", "", "<>", 5, "<>b<>a<>n<>a<>na"},
+	{"banana", "", "<>", 1, "<>banana"},
+	{"banana", "a", "a", -1, "banana"},
+	{"banana", "a", "a", 1, "banana"},
+	{"☺☻☹", "", "<>", -1, "<>☺<>☻<>☹<>"},
 }
 
 func TestReplace(t *testing.T) {
@@ -741,3 +731,46 @@ func TestReplace(t *testing.T) {
 		}
 	}
 }
+
+type TitleTest struct {
+	in, out string
+}
+
+var TitleTests = []TitleTest{
+	{"", ""},
+	{"a", "A"},
+	{" aaa aaa aaa ", " Aaa Aaa Aaa "},
+	{" Aaa Aaa Aaa ", " Aaa Aaa Aaa "},
+	{"123a456", "123a456"},
+	{"double-blind", "Double-Blind"},
+	{"ÿøû", "Ÿøû"},
+}
+
+func TestTitle(t *testing.T) {
+	for _, tt := range TitleTests {
+		if s := Title(tt.in); s != tt.out {
+			t.Errorf("Title(%q) = %q, want %q", tt.in, s, tt.out)
+		}
+	}
+}
+
+type ContainsTest struct {
+	str, substr string
+	expected    bool
+}
+
+var ContainsTests = []ContainsTest{
+	{"abc", "bc", true},
+	{"abc", "bcd", false},
+	{"abc", "", true},
+	{"", "a", false},
+}
+
+func TestContains(t *testing.T) {
+	for _, ct := range ContainsTests {
+		if Contains(ct.str, ct.substr) != ct.expected {
+			t.Errorf("Contains(%s, %s) = %v, want %v",
+				ct.str, ct.substr, !ct.expected, ct.expected)
+		}
+	}
+}