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package sprig
import (
"encoding/json"
"reflect"
)
// dfault checks whether `given` is set, and returns default if not set.
//
// This returns `d` if `given` appears not to be set, and `given` otherwise.
//
// For numeric types 0 is unset.
// For strings, maps, arrays, and slices, len() = 0 is considered unset.
// For bool, false is unset.
// Structs are never considered unset.
//
// For everything else, including pointers, a nil value is unset.
func dfault(d interface{}, given ...interface{}) interface{} {
if empty(given) || empty(given[0]) {
return d
}
return given[0]
}
// empty returns true if the given value has the zero value for its type.
func empty(given interface{}) bool {
g := reflect.ValueOf(given)
if !g.IsValid() {
return true
}
// Basically adapted from text/template.isTrue
switch g.Kind() {
default:
return g.IsNil()
case reflect.Array, reflect.Slice, reflect.Map, reflect.String:
return g.Len() == 0
case reflect.Bool:
return g.Bool() == false
case reflect.Complex64, reflect.Complex128:
return g.Complex() == 0
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return g.Int() == 0
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
return g.Uint() == 0
case reflect.Float32, reflect.Float64:
return g.Float() == 0
case reflect.Struct:
return false
}
}
// coalesce returns the first non-empty value.
func coalesce(v ...interface{}) interface{} {
for _, val := range v {
if !empty(val) {
return val
}
}
return nil
}
// toJson encodes an item into a JSON string
func toJson(v interface{}) string {
output, _ := json.Marshal(v)
return string(output)
}
// toPrettyJson encodes an item into a pretty (indented) JSON string
func toPrettyJson(v interface{}) string {
output, _ := json.MarshalIndent(v, "", " ")
return string(output)
}
// ternary returns the first value if the last value is true, otherwise returns the second value.
func ternary(vt interface{}, vf interface{}, v bool) interface{} {
if v {
return vt
}
return vf
}