otto/value_string.go

package otto

import (
    "math"
	"fmt"
)

func toString(value Value) string {
	if value._valueType == valueString {
		return value.value.(string)
	}
    if value.IsUndefined() {
        return "undefined"
    }
    if value.IsNull() {
        return "null"
    }
	switch realValue := value.value.(type) {
    case bool:
		return fmt.Sprintf("%v", realValue)
    case int, int8, int16, int32, int64:
		return fmt.Sprintf("%v", realValue)
    case uint, uint8, uint16, uint32, uint64:
		return fmt.Sprintf("%v", realValue)
    case float32:
		return fmt.Sprintf("%v", realValue)
    case float64:
        if math.IsNaN(realValue) {
            return "NaN"
        } else if math.IsInf(realValue, 0) {
			if math.Signbit(realValue) {
				return "-Infinity"
			}
            return "Infinity"
        }
		return fmt.Sprintf("%v", realValue)
    case string:
		return realValue
	case *_object:
		return toString(realValue.DefaultValue(defaultValueHintString))
	}
    panic(fmt.Errorf("toString(%v %T)", value.value, value.value))
}