chore: vendor

vendor/github.com/sergi/go-diff/diffmatchpatch/stringutil.go

@@ -0,0 +1,190 @@
+// Copyright (c) 2012-2016 The go-diff authors. All rights reserved.
+// https://github.com/sergi/go-diff
+// See the included LICENSE file for license details.
+//
+// go-diff is a Go implementation of Google's Diff, Match, and Patch library
+// Original library is Copyright (c) 2006 Google Inc.
+// http://code.google.com/p/google-diff-match-patch/
+
+package diffmatchpatch
+
+import (
+	"fmt"
+	"strings"
+	"unicode/utf8"
+)
+
+const UNICODE_INVALID_RANGE_START = 0xD800
+const UNICODE_INVALID_RANGE_END = 0xDFFF
+const UNICODE_INVALID_RANGE_DELTA = UNICODE_INVALID_RANGE_END - UNICODE_INVALID_RANGE_START + 1
+const UNICODE_RANGE_MAX = 0x10FFFF
+
+// unescaper unescapes selected chars for compatibility with JavaScript's encodeURI.
+// In speed critical applications this could be dropped since the receiving application will certainly decode these fine. Note that this function is case-sensitive.  Thus "%3F" would not be unescaped.  But this is ok because it is only called with the output of HttpUtility.UrlEncode which returns lowercase hex. Example: "%3f" -> "?", "%24" -> "$", etc.
+var unescaper = strings.NewReplacer(
+	"%21", "!", "%7E", "~", "%27", "'",
+	"%28", "(", "%29", ")", "%3B", ";",
+	"%2F", "/", "%3F", "?", "%3A", ":",
+	"%40", "@", "%26", "&", "%3D", "=",
+	"%2B", "+", "%24", "$", "%2C", ",", "%23", "#", "%2A", "*")
+
+// indexOf returns the first index of pattern in str, starting at str[i].
+func indexOf(str string, pattern string, i int) int {
+	if i > len(str)-1 {
+		return -1
+	}
+	if i <= 0 {
+		return strings.Index(str, pattern)
+	}
+	ind := strings.Index(str[i:], pattern)
+	if ind == -1 {
+		return -1
+	}
+	return ind + i
+}
+
+// lastIndexOf returns the last index of pattern in str, starting at str[i].
+func lastIndexOf(str string, pattern string, i int) int {
+	if i < 0 {
+		return -1
+	}
+	if i >= len(str) {
+		return strings.LastIndex(str, pattern)
+	}
+	_, size := utf8.DecodeRuneInString(str[i:])
+	return strings.LastIndex(str[:i+size], pattern)
+}
+
+// runesIndexOf returns the index of pattern in target, starting at target[i].
+func runesIndexOf(target, pattern []rune, i int) int {
+	if i > len(target)-1 {
+		return -1
+	}
+	if i <= 0 {
+		return runesIndex(target, pattern)
+	}
+	ind := runesIndex(target[i:], pattern)
+	if ind == -1 {
+		return -1
+	}
+	return ind + i
+}
+
+func runesEqual(r1, r2 []rune) bool {
+	if len(r1) != len(r2) {
+		return false
+	}
+	for i, c := range r1 {
+		if c != r2[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// runesIndex is the equivalent of strings.Index for rune slices.
+func runesIndex(r1, r2 []rune) int {
+	last := len(r1) - len(r2)
+	for i := 0; i <= last; i++ {
+		if runesEqual(r1[i:i+len(r2)], r2) {
+			return i
+		}
+	}
+	return -1
+}
+
+func intArrayToString(ns []uint32) string {
+	if len(ns) == 0 {
+		return ""
+	}
+
+	b := []rune{}
+	for _, n := range ns {
+		b = append(b, intToRune(n))
+	}
+	return string(b)
+}
+
+// These constants define the number of bits representable
+// in 1,2,3,4 byte utf8 sequences, respectively.
+const ONE_BYTE_BITS = 7
+const TWO_BYTE_BITS = 11
+const THREE_BYTE_BITS = 16
+const FOUR_BYTE_BITS = 21
+
+// Helper for getting a sequence of bits from an integer.
+func getBits(i uint32, cnt byte, from byte) byte {
+	return byte((i >> from) & ((1 << cnt) - 1))
+}
+
+// Converts an integer in the range 0~1112060 into a rune.
+// Based on the ranges table in https://en.wikipedia.org/wiki/UTF-8
+func intToRune(i uint32) rune {
+	if i < (1 << ONE_BYTE_BITS) {
+		return rune(i)
+	}
+
+	if i < (1 << TWO_BYTE_BITS) {
+		r, size := utf8.DecodeRune([]byte{0b11000000 | getBits(i, 5, 6), 0b10000000 | getBits(i, 6, 0)})
+		if size != 2 || r == utf8.RuneError {
+			panic(fmt.Sprintf("Error encoding an int %d with size 2, got rune %v and size %d", size, r, i))
+		}
+		return r
+	}
+
+	// Last -3 here needed because for some reason 3rd to last codepoint 65533 in this range
+	// was returning utf8.RuneError during encoding.
+	if i < ((1 << THREE_BYTE_BITS) - UNICODE_INVALID_RANGE_DELTA - 3) {
+		if i >= UNICODE_INVALID_RANGE_START {
+			i += UNICODE_INVALID_RANGE_DELTA
+		}
+
+		r, size := utf8.DecodeRune([]byte{0b11100000 | getBits(i, 4, 12), 0b10000000 | getBits(i, 6, 6), 0b10000000 | getBits(i, 6, 0)})
+		if size != 3 || r == utf8.RuneError {
+			panic(fmt.Sprintf("Error encoding an int %d with size 3, got rune %v and size %d", size, r, i))
+		}
+		return r
+	}
+
+	if i < (1<<FOUR_BYTE_BITS - UNICODE_INVALID_RANGE_DELTA - 3) {
+		i += UNICODE_INVALID_RANGE_DELTA + 3
+		r, size := utf8.DecodeRune([]byte{0b11110000 | getBits(i, 3, 18), 0b10000000 | getBits(i, 6, 12), 0b10000000 | getBits(i, 6, 6), 0b10000000 | getBits(i, 6, 0)})
+		if size != 4 || r == utf8.RuneError {
+			panic(fmt.Sprintf("Error encoding an int %d with size 4, got rune %v and size %d", size, r, i))
+		}
+		return r
+	}
+	panic(fmt.Sprintf("The integer %d is too large for runeToInt()", i))
+}
+
+// Converts a rune generated by intToRune back to an integer
+func runeToInt(r rune) uint32 {
+	i := uint32(r)
+	if i < (1 << ONE_BYTE_BITS) {
+		return i
+	}
+
+	bytes := []byte{0, 0, 0, 0}
+
+	size := utf8.EncodeRune(bytes, r)
+
+	if size == 2 {
+		return uint32(bytes[0]&0b11111)<<6 | uint32(bytes[1]&0b111111)
+	}
+
+	if size == 3 {
+		result := uint32(bytes[0]&0b1111)<<12 | uint32(bytes[1]&0b111111)<<6 | uint32(bytes[2]&0b111111)
+		if result >= UNICODE_INVALID_RANGE_END {
+			return result - UNICODE_INVALID_RANGE_DELTA
+		}
+
+		return result
+	}
+
+	if size == 4 {
+		result := uint32(bytes[0]&0b111)<<18 | uint32(bytes[1]&0b111111)<<12 | uint32(bytes[2]&0b111111)<<6 | uint32(bytes[3]&0b111111)
+		return result - UNICODE_INVALID_RANGE_DELTA - 3
+	}
+
+	panic(fmt.Sprintf("Unexpected state decoding rune=%v size=%d", r, size))
+}