mirror of https://gitea.com/gitea/tea.git
80 lines
2.5 KiB
Go
80 lines
2.5 KiB
Go
package survey
|
|
|
|
import (
|
|
"reflect"
|
|
"strings"
|
|
)
|
|
|
|
// TransformString returns a `Transformer` based on the "f"
|
|
// function which accepts a string representation of the answer
|
|
// and returns a new one, transformed, answer.
|
|
// Take for example the functions inside the std `strings` package,
|
|
// they can be converted to a compatible `Transformer` by using this function,
|
|
// i.e: `TransformString(strings.Title)`, `TransformString(strings.ToUpper)`.
|
|
//
|
|
// Note that `TransformString` is just a helper, `Transformer` can be used
|
|
// to transform any type of answer.
|
|
func TransformString(f func(s string) string) Transformer {
|
|
return func(ans interface{}) interface{} {
|
|
// if the answer value passed in is the zero value of the appropriate type
|
|
if isZero(reflect.ValueOf(ans)) {
|
|
// skip this `Transformer` by returning a zero value of string.
|
|
// The original answer will be not affected,
|
|
// see survey.go#L125.
|
|
// A zero value of string should be returned to be handled by
|
|
// next Transformer in a composed Tranformer,
|
|
// see tranform.go#L75
|
|
return ""
|
|
}
|
|
|
|
// "ans" is never nil here, so we don't have to check that
|
|
// see survey.go#L338 for more.
|
|
// Make sure that the the answer's value was a typeof string.
|
|
s, ok := ans.(string)
|
|
if !ok {
|
|
return ""
|
|
}
|
|
|
|
return f(s)
|
|
}
|
|
}
|
|
|
|
// ToLower is a `Transformer`.
|
|
// It receives an answer value
|
|
// and returns a copy of the "ans"
|
|
// with all Unicode letters mapped to their lower case.
|
|
//
|
|
// Note that if "ans" is not a string then it will
|
|
// return a nil value, meaning that the above answer
|
|
// will not be affected by this call at all.
|
|
func ToLower(ans interface{}) interface{} {
|
|
transformer := TransformString(strings.ToLower)
|
|
return transformer(ans)
|
|
}
|
|
|
|
// Title is a `Transformer`.
|
|
// It receives an answer value
|
|
// and returns a copy of the "ans"
|
|
// with all Unicode letters that begin words
|
|
// mapped to their title case.
|
|
//
|
|
// Note that if "ans" is not a string then it will
|
|
// return a nil value, meaning that the above answer
|
|
// will not be affected by this call at all.
|
|
func Title(ans interface{}) interface{} {
|
|
transformer := TransformString(strings.Title)
|
|
return transformer(ans)
|
|
}
|
|
|
|
// ComposeTransformers is a variadic function used to create one transformer from many.
|
|
func ComposeTransformers(transformers ...Transformer) Transformer {
|
|
// return a transformer that calls each one sequentially
|
|
return func(ans interface{}) interface{} {
|
|
// execute each transformer
|
|
for _, t := range transformers {
|
|
ans = t(ans)
|
|
}
|
|
return ans
|
|
}
|
|
}
|