chore: vendor

vendor/github.com/AlecAivazis/survey/v2/transform.go

@@ -0,0 +1,82 @@
+package survey
+
+import (
+	"reflect"
+	"strings"
+
+	"golang.org/x/text/cases"
+	"golang.org/x/text/language"
+)
+
+// 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(cases.Title(language.English).String)
+	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
+	}
+}