complete/predicate.go

107 lines
2.2 KiB
Go

package complete
import (
"os"
"path/filepath"
)
// Predicate determines what terms can follow a command or a flag
type Predicate struct {
// Expects determine if the predicate expects something after.
// flags/commands that do not expect any specific argument should
// leave it on false
Expects bool
// Predictor is function that returns list of arguments that can
// come after the flag/command
Predictor func() []Option
}
// Or unions two predicate struct, so that the result predicate
// returns the union of their predication
func (p Predicate) Or(other Predicate) Predicate {
return Predicate{
Expects: p.Expects && other.Expects,
Predictor: func() []Option { return append(p.predict(), other.predict()...) },
}
}
func (p Predicate) predict() []Option {
if p.Predictor == nil {
return nil
}
return p.Predictor()
}
var (
PredictNothing = Predicate{Expects: false}
PredictAnything = Predicate{Expects: true}
)
func PredictFiles(pattern string) Predicate {
return Predicate{
Expects: true,
Predictor: glob(pattern),
}
}
func PredictDirs(path string) Predicate {
return Predicate{
Expects: true,
Predictor: dirs(path),
}
}
func dirs(path string) func() []Option {
return func() (options []Option) {
dirs := []string{}
filepath.Walk(path, func(path string, info os.FileInfo, err error) error {
if info.IsDir() {
dirs = append(dirs, path)
}
return nil
})
if !filepath.IsAbs(path) {
filesToRel(dirs)
}
return filesToOptions(dirs)
}
}
func glob(pattern string) func() []Option {
return func() []Option {
files, err := filepath.Glob(pattern)
if err != nil {
logger("failed glob operation with pattern '%s': %s", pattern, err)
}
if !filepath.IsAbs(pattern) {
filesToRel(files)
}
return filesToOptions(files)
}
}
func filesToRel(files []string) {
wd, err := os.Getwd()
if err != nil {
return
}
for i := range files {
abs, err := filepath.Abs(files[i])
if err != nil {
continue
}
rel, err := filepath.Rel(wd, abs)
if err != nil {
continue
}
files[i] = "./" + rel
}
return
}
func filesToOptions(files []string) []Option {
options := make([]Option, len(files))
for i, f := range files {
options[i] = ArgFileName(f)
}
return options
}