chore: import upstream snapshot with attribution

go/libraries/utils/strhelp/string_help.go

@@ -0,0 +1,85 @@
+// Copyright 2019 Dolthub, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package strhelp
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+// NthToken returns the Nth token in s, delimited by delim. There is always at least one token: the zeroth token is the
+// input string if delim doesn't occur in s. The second return value will be false if there is no Nth token.
+func NthToken(s string, delim rune, n int) (string, bool) {
+	if n < 0 {
+		panic("invalid arguments.")
+	}
+
+	prev := 0
+	curr := 0
+	for ; curr < len(s); curr++ {
+		if s[curr] == uint8(delim) {
+			n--
+
+			if n >= 0 {
+				prev = curr + 1
+			} else {
+				break
+			}
+		}
+	}
+
+	if n <= 0 && prev <= curr {
+		return s[prev:curr], true
+	}
+
+	return "", false
+}
+
+func CommaIfy(n int64) string {
+	str := strconv.FormatInt(n, 10)
+
+	if len(str) < 4 {
+		return str
+	}
+
+	result := ""
+
+	for i := len(str); i >= 0; i -= 3 {
+		if i-4 >= 0 {
+			result = "," + str[i-3:i] + result
+		} else {
+			result = str[0:i] + result
+		}
+	}
+
+	return result
+}
+
+// LineStrBuilder is a utility class for building strings line by line
+type LineStrBuilder []string
+
+// AppendLine works like append in that it returns an instance of a LineStrBuilder with the contents updated to contain
+// the additional line. lsb = lsb.AppendLine("n: %d, s: %s", n, s)
+func (lsb LineStrBuilder) AppendLine(strFmt string, args ...interface{}) LineStrBuilder {
+	updated := append(lsb, fmt.Sprintf(strFmt, args...))
+	return updated
+}
+
+// String returns the built string with all lines separated by newlines
+func (lsb LineStrBuilder) String() string {
+	s := strings.Join(lsb, "\n")
+	return s
+}