diff options
| -rw-r--r-- | src/pkg/bytes/bytes.go | 24 | ||||
| -rw-r--r-- | src/pkg/bytes/bytes_test.go | 31 | ||||
| -rw-r--r-- | src/pkg/strings/strings.go | 23 | ||||
| -rw-r--r-- | src/pkg/strings/strings_test.go | 30 |
4 files changed, 98 insertions, 10 deletions
diff --git a/src/pkg/bytes/bytes.go b/src/pkg/bytes/bytes.go index 6a36829e1..cb543991c 100644 --- a/src/pkg/bytes/bytes.go +++ b/src/pkg/bytes/bytes.go @@ -127,10 +127,9 @@ func LastIndex(s, sep []byte) int { return -1; } -// Split splits the array s around each instance of sep, returning an array of subarrays of s. -// If sep is empty, Split splits s after each UTF-8 sequence. -// If n > 0, split Splits s into at most n subarrays; the last subarray will contain an unsplit remainder. -func Split(s, sep []byte, n int) [][]byte { +// Generic split: splits after each instance of sep, +// including sepSave bytes of sep in the subarrays. +func genSplit(s, sep []byte, sepSave, n int) [][]byte { if len(sep) == 0 { return explode(s, n); } @@ -143,7 +142,7 @@ func Split(s, sep []byte, n int) [][]byte { na := 0; for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ { if s[i] == c && (len(sep) == 1 || Equal(s[i : i+len(sep)], sep)) { - a[na] = s[start:i]; + a[na] = s[start:i+sepSave]; na++; start = i+len(sep); i += len(sep)-1; @@ -153,6 +152,21 @@ func Split(s, sep []byte, n int) [][]byte { return a[0 : na+1]; } +// Split splits the array s around each instance of sep, returning an array of subarrays of s. +// If sep is empty, Split splits s after each UTF-8 sequence. +// If n > 0, Split splits s into at most n subarrays; the last subarray will contain an unsplit remainder. +func Split(s, sep []byte, n int) [][]byte { + return genSplit(s, sep, 0, n); +} + +// SplitAfter splits the array s after each instance of sep, returning an array of subarrays of s. +// If sep is empty, SplitAfter splits s after each UTF-8 sequence. +// If n > 0, SplitAfter splits s into at most n subarrays; the last subarray will contain an +// unsplit remainder. +func SplitAfter(s, sep []byte, n int) [][]byte { + return genSplit(s, sep, len(sep), n); +} + // Join concatenates the elements of a to create a single byte array. The separator // sep is placed between elements in the resulting array. func Join(a [][]byte, sep []byte) []byte { diff --git a/src/pkg/bytes/bytes_test.go b/src/pkg/bytes/bytes_test.go index 24ee4bf4d..ee727f0cd 100644 --- a/src/pkg/bytes/bytes_test.go +++ b/src/pkg/bytes/bytes_test.go @@ -141,6 +141,37 @@ func TestSplit(t *testing.T) { } } +var splitaftertests = []SplitTest{ + SplitTest{abcd, "a", 0, []string{"a", "bcd"}}, + SplitTest{abcd, "z", 0, []string{"abcd"}}, + SplitTest{abcd, "", 0, []string{"a", "b", "c", "d"}}, + SplitTest{commas, ",", 0, []string{"1,", "2,", "3,", "4"}}, + SplitTest{dots, "...", 0, []string{"1...", ".2...", ".3...", ".4"}}, + SplitTest{faces, "☹", 0, []string{"☺☻☹", ""}}, + SplitTest{faces, "~", 0, []string{faces}}, + SplitTest{faces, "", 0, []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"}}, +} + +func TestSplitAfter(t *testing.T) { + for _, tt := range splitaftertests { + a := SplitAfter(strings.Bytes(tt.s), strings.Bytes(tt.sep), tt.n); + result := arrayOfString(a); + if !eq(result, tt.a) { + t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, result, tt.a); + continue; + } + s := Join(a, nil); + if string(s) != tt.s { + t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s); + } + } +} + type CopyTest struct { a string; b string; diff --git a/src/pkg/strings/strings.go b/src/pkg/strings/strings.go index f4b969b42..ecfb088cd 100644 --- a/src/pkg/strings/strings.go +++ b/src/pkg/strings/strings.go @@ -79,10 +79,9 @@ func LastIndex(s, sep string) int { return -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 subarray will contain an unsplit remainder string. -func Split(s, sep string, n int) []string { +// 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 { if sep == "" { return explode(s, n) } @@ -95,7 +94,7 @@ func Split(s, sep string, n int) []string { na := 0; for i := 0; i+len(sep) <= len(s) && na+1 < n; i++ { if s[i] == c && (len(sep) == 1 || s[i:i+len(sep)] == sep) { - a[na] = s[start:i]; + a[na] = s[start:i+sepSave]; na++; start = i+len(sep); i += len(sep)-1; @@ -105,6 +104,20 @@ func Split(s, sep string, 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. +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. +func SplitAfter(s, sep string, n int) []string { + return genSplit(s, sep, len(sep), n); +} + // 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 { diff --git a/src/pkg/strings/strings_test.go b/src/pkg/strings/strings_test.go index bdc7f9f08..0db3c9741 100644 --- a/src/pkg/strings/strings_test.go +++ b/src/pkg/strings/strings_test.go @@ -145,6 +145,36 @@ func TestSplit(t *testing.T) { } } +var splitaftertests = []SplitTest{ + SplitTest{abcd, "a", 0, []string{"a", "bcd"}}, + SplitTest{abcd, "z", 0, []string{"abcd"}}, + SplitTest{abcd, "", 0, []string{"a", "b", "c", "d"}}, + SplitTest{commas, ",", 0, []string{"1,", "2,", "3,", "4"}}, + SplitTest{dots, "...", 0, []string{"1...", ".2...", ".3...", ".4"}}, + SplitTest{faces, "☹", 0, []string{"☺☻☹", ""}}, + SplitTest{faces, "~", 0, []string{faces}}, + SplitTest{faces, "", 0, []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"}}, +} + +func TestSplitAfter(t *testing.T) { + for _, tt := range splitaftertests { + a := SplitAfter(tt.s, tt.sep, tt.n); + if !eq(a, tt.a) { + t.Errorf(`Split(%q, %q, %d) = %v; want %v`, tt.s, tt.sep, tt.n, a, tt.a); + continue; + } + s := Join(a, ""); + if s != tt.s { + t.Errorf(`Join(Split(%q, %q, %d), %q) = %q`, tt.s, tt.sep, tt.n, tt.sep, s); + } + } +} + // Test case for any function which accepts and returns a single string. type StringTest struct { in, out string; |