spf13--cobra/cobra.go
Albert Nigmatzianov 4d2c4afa04 Improve template mechanisms
* Delete Eq, Gt, appendIfNotPresent and trim functions

* Add "[flags]" in UseLine

* Simplify other functions

* Simplify templates

Minor performance improvement.
Benchmark for command with 4 flags and one child command:
benchmark                   old ns/op     new ns/op     delta
BenchmarkCmdUsageFunc-4     335860        319290        -4.93%

benchmark                   old allocs     new allocs     delta
BenchmarkCmdUsageFunc-4     562            543            -3.38%

benchmark                   old bytes     new bytes     delta
BenchmarkCmdUsageFunc-4     21623         21037         -2.71%
2017-05-08 14:22:04 +02:00

112 lines
3 KiB
Go

// Copyright © 2013 Steve Francia <spf@spf13.com>.
//
// 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.
// Commands similar to git, go tools and other modern CLI tools
// inspired by go, go-Commander, gh and subcommand
package cobra
import (
"fmt"
"io"
"strings"
"text/template"
"unicode"
)
var templateFuncs = template.FuncMap{
"trimTrailingWhitespaces": trimTrailingWhitespaces,
"rpad": rpad,
}
var initializers []func()
// EnablePrefixMatching allows to set automatic prefix matching. Automatic prefix matching can be a dangerous thing
// to automatically enable in CLI tools.
// Set this to true to enable it.
var EnablePrefixMatching = false
// EnableCommandSorting controls sorting of the slice of commands, which is turned on by default.
// To disable sorting, set it to false.
var EnableCommandSorting = true
// AddTemplateFunc adds a template function that's available to Usage and Help
// template generation.
func AddTemplateFunc(name string, tmplFunc interface{}) {
templateFuncs[name] = tmplFunc
}
// AddTemplateFuncs adds multiple template functions that are available to Usage and
// Help template generation.
func AddTemplateFuncs(tmplFuncs template.FuncMap) {
for k, v := range tmplFuncs {
templateFuncs[k] = v
}
}
// OnInitialize takes a series of func() arguments and appends them to a slice of func().
func OnInitialize(y ...func()) {
initializers = append(initializers, y...)
}
func trimTrailingWhitespaces(s string) string {
return strings.TrimRightFunc(s, unicode.IsSpace)
}
// rpad adds padding to the right of a string.
func rpad(s string, padding int) string {
template := fmt.Sprintf("%%-%ds", padding)
return fmt.Sprintf(template, s)
}
// tmpl executes the given template text on data, writing the result to w.
func tmpl(w io.Writer, text string, data interface{}) error {
t := template.New("top").Funcs(templateFuncs)
return template.Must(t.Parse(text)).Execute(w, data)
}
// ld compares two strings and returns the levenshtein distance between them.
func ld(s, t string, ignoreCase bool) int {
if ignoreCase {
s = strings.ToLower(s)
t = strings.ToLower(t)
}
d := make([][]int, len(s)+1)
for i := range d {
d[i] = make([]int, len(t)+1)
}
for i := range d {
d[i][0] = i
}
for j := range d[0] {
d[0][j] = j
}
for j := 1; j <= len(t); j++ {
for i := 1; i <= len(s); i++ {
if s[i-1] == t[j-1] {
d[i][j] = d[i-1][j-1]
} else {
min := d[i-1][j]
if d[i][j-1] < min {
min = d[i][j-1]
}
if d[i-1][j-1] < min {
min = d[i-1][j-1]
}
d[i][j] = min + 1
}
}
}
return d[len(s)][len(t)]
}