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-rw-r--r--vendor/github.com/kr/text/wrap.go86
1 files changed, 86 insertions, 0 deletions
diff --git a/vendor/github.com/kr/text/wrap.go b/vendor/github.com/kr/text/wrap.go
new file mode 100644
index 000000000..b09bb0373
--- /dev/null
+++ b/vendor/github.com/kr/text/wrap.go
@@ -0,0 +1,86 @@
+package text
+
+import (
+ "bytes"
+ "math"
+)
+
+var (
+ nl = []byte{'\n'}
+ sp = []byte{' '}
+)
+
+const defaultPenalty = 1e5
+
+// Wrap wraps s into a paragraph of lines of length lim, with minimal
+// raggedness.
+func Wrap(s string, lim int) string {
+ return string(WrapBytes([]byte(s), lim))
+}
+
+// WrapBytes wraps b into a paragraph of lines of length lim, with minimal
+// raggedness.
+func WrapBytes(b []byte, lim int) []byte {
+ words := bytes.Split(bytes.Replace(bytes.TrimSpace(b), nl, sp, -1), sp)
+ var lines [][]byte
+ for _, line := range WrapWords(words, 1, lim, defaultPenalty) {
+ lines = append(lines, bytes.Join(line, sp))
+ }
+ return bytes.Join(lines, nl)
+}
+
+// WrapWords is the low-level line-breaking algorithm, useful if you need more
+// control over the details of the text wrapping process. For most uses, either
+// Wrap or WrapBytes will be sufficient and more convenient.
+//
+// WrapWords splits a list of words into lines with minimal "raggedness",
+// treating each byte as one unit, accounting for spc units between adjacent
+// words on each line, and attempting to limit lines to lim units. Raggedness
+// is the total error over all lines, where error is the square of the
+// difference of the length of the line and lim. Too-long lines (which only
+// happen when a single word is longer than lim units) have pen penalty units
+// added to the error.
+func WrapWords(words [][]byte, spc, lim, pen int) [][][]byte {
+ n := len(words)
+
+ length := make([][]int, n)
+ for i := 0; i < n; i++ {
+ length[i] = make([]int, n)
+ length[i][i] = len(words[i])
+ for j := i + 1; j < n; j++ {
+ length[i][j] = length[i][j-1] + spc + len(words[j])
+ }
+ }
+
+ nbrk := make([]int, n)
+ cost := make([]int, n)
+ for i := range cost {
+ cost[i] = math.MaxInt32
+ }
+ for i := n - 1; i >= 0; i-- {
+ if length[i][n-1] <= lim || i == n-1 {
+ cost[i] = 0
+ nbrk[i] = n
+ } else {
+ for j := i + 1; j < n; j++ {
+ d := lim - length[i][j-1]
+ c := d*d + cost[j]
+ if length[i][j-1] > lim {
+ c += pen // too-long lines get a worse penalty
+ }
+ if c < cost[i] {
+ cost[i] = c
+ nbrk[i] = j
+ }
+ }
+ }
+ }
+
+ var lines [][][]byte
+ i := 0
+ for i < n {
+ lines = append(lines, words[i:nbrk[i]])
+ i = nbrk[i]
+ }
+ return lines
+}