package otto
import (
"fmt"
"math"
"regexp"
"strconv"
"unicode/utf16"
)
var matchLeading0Exponent = regexp.MustCompile(`([eE][\+\-])0+([1-9])`) // 1e-07 => 1e-7
// FIXME
// https://code.google.com/p/v8/source/browse/branches/bleeding_edge/src/conversions.cc?spec=svn18082&r=18082
func floatToString(value float64, bitsize int) string {
// TODO Fit to ECMA-262 9.8.1 specification
if math.IsNaN(value) {
return "NaN"
} else if math.IsInf(value, 0) {
if math.Signbit(value) {
return "-Infinity"
}
return "Infinity"
}
exponent := math.Log10(math.Abs(value))
if exponent >= 21 || exponent < -6 {
return matchLeading0Exponent.ReplaceAllString(strconv.FormatFloat(value, 'g', -1, bitsize), "$1$2")
}
return strconv.FormatFloat(value, 'f', -1, bitsize)
}
func numberToStringRadix(value Value, radix int) string {
float := value.float64()
if math.IsNaN(float) {
return "NaN"
} else if math.IsInf(float, 1) {
return "Infinity"
} else if math.IsInf(float, -1) {
return "-Infinity"
}
// FIXME This is very broken
// Need to do proper radix conversion for floats, ...
// This truncates large floats (so bad).
return strconv.FormatInt(int64(float), radix)
}
func (value Value) string() string {
if value.kind == valueString {
switch value := value.value.(type) {
case string:
return value
case []uint16:
return string(utf16.Decode(value))
}
}
if value.IsUndefined() {
return "undefined"
}
if value.IsNull() {
return "null"
}
switch value := value.value.(type) {
case bool:
return strconv.FormatBool(value)
case int:
return strconv.FormatInt(int64(value), 10)
case int8:
return strconv.FormatInt(int64(value), 10)
case int16:
return strconv.FormatInt(int64(value), 10)
case int32:
return strconv.FormatInt(int64(value), 10)
case int64:
return strconv.FormatInt(value, 10)
case uint:
return strconv.FormatUint(uint64(value), 10)
case uint8:
return strconv.FormatUint(uint64(value), 10)
case uint16:
return strconv.FormatUint(uint64(value), 10)
case uint32:
return strconv.FormatUint(uint64(value), 10)
case uint64:
return strconv.FormatUint(value, 10)
case float32:
if value == 0 {
return "0" // Take care not to return -0
}
return floatToString(float64(value), 32)
case float64:
if value == 0 {
return "0" // Take care not to return -0
}
return floatToString(value, 64)
case []uint16:
return string(utf16.Decode(value))
case string:
return value
case *_object:
return value.DefaultValue(defaultValueHintString).string()
}
panic(fmt.Errorf("%v.string( %T)", value.value, value.value))
}
