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// Copyright 2016 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package grumpy
import (
"fmt"
"math"
"math/big"
"reflect"
"strconv"
"strings"
"sync/atomic"
"unicode"
"unsafe"
)
// FloatType is the object representing the Python 'float' type.
var FloatType = newBasisType("float", reflect.TypeOf(Float{}), toFloatUnsafe, ObjectType)
// Float represents Python 'float' objects.
type Float struct {
Object
value float64
hash int
}
// NewFloat returns a new Float holding the given floating point value.
func NewFloat(value float64) *Float {
return &Float{Object: Object{typ: FloatType}, value: value}
}
func toFloatUnsafe(o *Object) *Float {
return (*Float)(o.toPointer())
}
// ToObject upcasts f to an Object.
func (f *Float) ToObject() *Object {
return &f.Object
}
// Value returns the underlying floating point value held by f.
func (f *Float) Value() float64 {
return f.value
}
func floatAbs(f *Frame, o *Object) (*Object, *BaseException) {
z := toFloatUnsafe(o).Value()
return NewFloat(math.Abs(z)).ToObject(), nil
}
func floatAdd(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__add__", v, w, func(v, w float64) float64 { return v + w })
}
func floatDiv(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__div__", v, w, func(v, w float64) (float64, bool) {
if w == 0.0 {
return 0, false
}
return v / w, true
})
}
func floatDivMod(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivAndModOp(f, "__divmod__", v, w, func(v, w float64) (float64, float64, bool) {
m, r := floatModFunc(v, w)
if !r {
return 0, 0, false
}
return math.Floor(v / w), m, true
})
}
func floatEq(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, False, True, False), nil
}
func floatFloat(f *Frame, o *Object) (*Object, *BaseException) {
return o, nil
}
func floatFloorDiv(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__floordiv__", v, w, func(v, w float64) (float64, bool) {
if w == 0.0 {
return 0, false
}
return math.Floor(v / w), true
})
}
func floatGE(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, False, True, True), nil
}
func floatGetNewArgs(f *Frame, args Args, _ KWArgs) (*Object, *BaseException) {
if raised := checkMethodArgs(f, "__getnewargs__", args, FloatType); raised != nil {
return nil, raised
}
return NewTuple1(args[0]).ToObject(), nil
}
func floatGT(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, False, False, True), nil
}
func floatHash(f *Frame, o *Object) (*Object, *BaseException) {
v := toFloatUnsafe(o)
p := (*unsafe.Pointer)(unsafe.Pointer(&v.hash))
if lp := atomic.LoadPointer(p); lp != unsafe.Pointer(nil) {
return (*Int)(lp).ToObject(), nil
}
hash := hashFloat(v.Value())
if hash == -1 {
hash--
}
h := NewInt(hash)
atomic.StorePointer(p, unsafe.Pointer(h))
return h.ToObject(), nil
}
func floatInt(f *Frame, o *Object) (*Object, *BaseException) {
val := toFloatUnsafe(o).Value()
if math.IsInf(val, 0) {
return nil, f.RaiseType(OverflowErrorType, "cannot convert float infinity to integer")
}
if math.IsNaN(val) {
return nil, f.RaiseType(OverflowErrorType, "cannot convert float NaN to integer")
}
i := big.Int{}
big.NewFloat(val).Int(&i)
if !numInIntRange(&i) {
return NewLong(&i).ToObject(), nil
}
return NewInt(int(i.Int64())).ToObject(), nil
}
func floatLong(f *Frame, o *Object) (*Object, *BaseException) {
val := toFloatUnsafe(o).Value()
if math.IsInf(val, 0) {
return nil, f.RaiseType(OverflowErrorType, "cannot convert float infinity to integer")
}
if math.IsNaN(val) {
return nil, f.RaiseType(OverflowErrorType, "cannot convert float NaN to integer")
}
i, _ := big.NewFloat(val).Int(nil)
return NewLong(i).ToObject(), nil
}
func floatLE(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, True, True, False), nil
}
func floatLT(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, True, False, False), nil
}
func floatMod(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__mod__", v, w, floatModFunc)
}
func floatMul(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__mul__", v, w, func(v, w float64) float64 { return v * w })
}
func floatNative(f *Frame, o *Object) (reflect.Value, *BaseException) {
return reflect.ValueOf(toFloatUnsafe(o).Value()), nil
}
func floatNE(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatCompare(toFloatUnsafe(v), w, True, False, True), nil
}
func floatNeg(f *Frame, o *Object) (*Object, *BaseException) {
z := toFloatUnsafe(o).Value()
return NewFloat(-z).ToObject(), nil
}
func floatNew(f *Frame, t *Type, args Args, _ KWArgs) (*Object, *BaseException) {
argc := len(args)
if argc == 0 {
return newObject(t), nil
}
if argc != 1 {
return nil, f.RaiseType(TypeErrorType, "'__new__' of 'float' requires 0 or 1 arguments")
}
if t != FloatType {
// Allocate a plain float then copy it's value into an object
// of the float subtype.
x, raised := floatNew(f, FloatType, args, nil)
if raised != nil {
return nil, raised
}
result := toFloatUnsafe(newObject(t))
result.value = toFloatUnsafe(x).Value()
return result.ToObject(), nil
}
o := args[0]
if floatSlot := o.typ.slots.Float; floatSlot != nil {
fl, raised := floatConvert(floatSlot, f, o)
if raised != nil {
return nil, raised
}
return fl.ToObject(), nil
}
if !o.isInstance(StrType) {
return nil, f.RaiseType(TypeErrorType, "float() argument must be a string or a number")
}
s := toStrUnsafe(o).Value()
result, err := strconv.ParseFloat(s, 64)
if err != nil {
return nil, f.RaiseType(ValueErrorType, fmt.Sprintf("could not convert string to float: %s", s))
}
return NewFloat(result).ToObject(), nil
}
func floatNonZero(f *Frame, o *Object) (*Object, *BaseException) {
return GetBool(toFloatUnsafe(o).Value() != 0).ToObject(), nil
}
func floatPos(f *Frame, o *Object) (*Object, *BaseException) {
return o, nil
}
func floatPow(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__pow__", v, w, func(v, w float64) float64 { return math.Pow(v, w) })
}
func floatRAdd(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__radd__", v, w, func(v, w float64) float64 { return w + v })
}
func floatRDiv(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__rdiv__", v, w, func(v, w float64) (float64, bool) {
if v == 0.0 {
return 0, false
}
return w / v, true
})
}
func floatRDivMod(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivAndModOp(f, "__rdivmod__", v, w, func(v, w float64) (float64, float64, bool) {
m, r := floatModFunc(w, v)
if !r {
return 0, 0, false
}
return w / v, m, true
})
}
const (
floatReprPrecision = 16
floatStrPrecision = 12
)
func floatRepr(f *Frame, o *Object) (*Object, *BaseException) {
return NewStr(floatToString(toFloatUnsafe(o).Value(), floatReprPrecision)).ToObject(), nil
}
func floatRFloorDiv(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__rfloordiv__", v, w, func(v, w float64) (float64, bool) {
if v == 0.0 {
return 0, false
}
return math.Floor(w / v), true
})
}
func floatRMod(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatDivModOp(f, "__rmod__", v, w, func(v, w float64) (float64, bool) {
return floatModFunc(w, v)
})
}
func floatRMul(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__rmul__", v, w, func(v, w float64) float64 { return w * v })
}
func floatRPow(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__rpow", v, w, func(v, w float64) float64 { return math.Pow(w, v) })
}
func floatRSub(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__rsub__", v, w, func(v, w float64) float64 { return w - v })
}
func floatStr(f *Frame, o *Object) (*Object, *BaseException) {
return NewStr(floatToString(toFloatUnsafe(o).Value(), floatStrPrecision)).ToObject(), nil
}
func floatSub(f *Frame, v, w *Object) (*Object, *BaseException) {
return floatArithmeticOp(f, "__sub__", v, w, func(v, w float64) float64 { return v - w })
}
func initFloatType(dict map[string]*Object) {
dict["__getnewargs__"] = newBuiltinFunction("__getnewargs__", floatGetNewArgs).ToObject()
FloatType.slots.Abs = &unaryOpSlot{floatAbs}
FloatType.slots.Add = &binaryOpSlot{floatAdd}
FloatType.slots.Div = &binaryOpSlot{floatDiv}
FloatType.slots.DivMod = &binaryOpSlot{floatDivMod}
FloatType.slots.Eq = &binaryOpSlot{floatEq}
FloatType.slots.Float = &unaryOpSlot{floatFloat}
FloatType.slots.FloorDiv = &binaryOpSlot{floatFloorDiv}
FloatType.slots.GE = &binaryOpSlot{floatGE}
FloatType.slots.GT = &binaryOpSlot{floatGT}
FloatType.slots.Hash = &unaryOpSlot{floatHash}
FloatType.slots.Int = &unaryOpSlot{floatInt}
FloatType.slots.Long = &unaryOpSlot{floatLong}
FloatType.slots.LE = &binaryOpSlot{floatLE}
FloatType.slots.LT = &binaryOpSlot{floatLT}
FloatType.slots.Mod = &binaryOpSlot{floatMod}
FloatType.slots.Mul = &binaryOpSlot{floatMul}
FloatType.slots.Native = &nativeSlot{floatNative}
FloatType.slots.NE = &binaryOpSlot{floatNE}
FloatType.slots.Neg = &unaryOpSlot{floatNeg}
FloatType.slots.New = &newSlot{floatNew}
FloatType.slots.NonZero = &unaryOpSlot{floatNonZero}
FloatType.slots.Pos = &unaryOpSlot{floatPos}
FloatType.slots.Pow = &binaryOpSlot{floatPow}
FloatType.slots.RAdd = &binaryOpSlot{floatRAdd}
FloatType.slots.RDiv = &binaryOpSlot{floatRDiv}
FloatType.slots.RDivMod = &binaryOpSlot{floatRDivMod}
FloatType.slots.Repr = &unaryOpSlot{floatRepr}
FloatType.slots.RFloorDiv = &binaryOpSlot{floatRFloorDiv}
FloatType.slots.RMod = &binaryOpSlot{floatRMod}
FloatType.slots.RMul = &binaryOpSlot{floatRMul}
FloatType.slots.RPow = &binaryOpSlot{floatRPow}
FloatType.slots.RSub = &binaryOpSlot{floatRSub}
FloatType.slots.Str = &unaryOpSlot{floatStr}
FloatType.slots.Sub = &binaryOpSlot{floatSub}
}
func floatArithmeticOp(f *Frame, method string, v, w *Object, fun func(v, w float64) float64) (*Object, *BaseException) {
floatW, ok := floatCoerce(w)
if !ok {
if math.IsInf(floatW, 0) {
return nil, f.RaiseType(OverflowErrorType, "long int too large to convert to float")
}
return NotImplemented, nil
}
return NewFloat(fun(toFloatUnsafe(v).Value(), floatW)).ToObject(), nil
}
func floatCompare(v *Float, w *Object, ltResult, eqResult, gtResult *Int) *Object {
lhs := v.Value()
rhs, ok := floatCoerce(w)
if !ok {
if !math.IsInf(rhs, 0) {
return NotImplemented
}
// When floatCoerce returns (Inf, false) it indicates an
// overflow - abs(rhs) is between MaxFloat64 and Inf.
// When comparing with infinite floats, rhs might as well be 0.
// Otherwise, let the compare proceed normally as |rhs| might
// as well be infinite, since it's outside the range of finite
// floats.
if math.IsInf(lhs, 0) {
rhs = 0
}
}
if lhs < rhs {
return ltResult.ToObject()
}
if lhs == rhs {
return eqResult.ToObject()
}
if lhs > rhs {
return gtResult.ToObject()
}
// There must be a NaN involved, which always compares false, even to other NaNs.
// This is true both in Go and in Python.
return False.ToObject()
}
// floatCoerce will coerce any numeric type to a float. If all is
// well, it will return the float64 value, and true (OK). If an overflow
// occurs, it will return either (+Inf, false) or (-Inf, false) depending
// on whether the source value was too large or too small. Note that if the
// source number is an infinite float, the result will be infinite without
// overflow, (+-Inf, true).
// If the input is not a number, it will return (0, false).
func floatCoerce(o *Object) (float64, bool) {
switch {
case o.isInstance(IntType):
return float64(toIntUnsafe(o).Value()), true
case o.isInstance(LongType):
f, _ := new(big.Float).SetInt(toLongUnsafe(o).Value()).Float64()
// If f is infinite, that indicates the big.Int was too large
// or too small to be represented as a float64. In that case,
// indicate the overflow by returning (f, false).
overflow := math.IsInf(f, 0)
return f, !overflow
case o.isInstance(FloatType):
return toFloatUnsafe(o).Value(), true
default:
return 0, false
}
}
func floatConvert(floatSlot *unaryOpSlot, f *Frame, o *Object) (*Float, *BaseException) {
result, raised := floatSlot.Fn(f, o)
if raised != nil {
return nil, raised
}
if !result.isInstance(FloatType) {
exc := fmt.Sprintf("__float__ returned non-float (type %s)", result.typ.Name())
return nil, f.RaiseType(TypeErrorType, exc)
}
return toFloatUnsafe(result), nil
}
func floatDivModOp(f *Frame, method string, v, w *Object, fun func(v, w float64) (float64, bool)) (*Object, *BaseException) {
floatW, ok := floatCoerce(w)
if !ok {
if math.IsInf(floatW, 0) {
return nil, f.RaiseType(OverflowErrorType, "long int too large to convert to float")
}
return NotImplemented, nil
}
x, ok := fun(toFloatUnsafe(v).Value(), floatW)
if !ok {
return nil, f.RaiseType(ZeroDivisionErrorType, "float division or modulo by zero")
}
return NewFloat(x).ToObject(), nil
}
func floatDivAndModOp(f *Frame, method string, v, w *Object, fun func(v, w float64) (float64, float64, bool)) (*Object, *BaseException) {
floatW, ok := floatCoerce(w)
if !ok {
if math.IsInf(floatW, 0) {
return nil, f.RaiseType(OverflowErrorType, "long int too large to convert to float")
}
return NotImplemented, nil
}
q, m, ok := fun(toFloatUnsafe(v).Value(), floatW)
if !ok {
return nil, f.RaiseType(ZeroDivisionErrorType, "float division or modulo by zero")
}
return NewTuple2(NewFloat(q).ToObject(), NewFloat(m).ToObject()).ToObject(), nil
}
func hashFloat(v float64) int {
if math.IsNaN(v) {
return 0
}
if math.IsInf(v, 0) {
if math.IsInf(v, 1) {
return 314159
}
if math.IsInf(v, -1) {
return -271828
}
return 0
}
_, fracPart := math.Modf(v)
if fracPart == 0.0 {
i := big.Int{}
big.NewFloat(v).Int(&i)
if numInIntRange(&i) {
return int(i.Int64())
}
// TODO: hashBigInt() is not yet matched that of cpython or pypy.
return hashBigInt(&i)
}
v, expo := math.Frexp(v)
v *= 2147483648.0
hiPart := int(v)
v = (v - float64(hiPart)) * 2147483648.0
x := int(hiPart + int(v) + (expo << 15))
return x
}
func floatModFunc(v, w float64) (float64, bool) {
if w == 0.0 {
return 0, false
}
x := math.Mod(v, w)
if x != 0 && math.Signbit(x) != math.Signbit(w) {
// In Python the result of the modulo operator is
// always the same sign as the divisor, whereas in Go,
// the result is always the same sign as the dividend.
// Therefore we need to do an adjustment when the sign
// of the modulo result differs from that of the
// divisor.
x += w
}
return x, true
}
func floatToString(f float64, p int) string {
s := unsignPositiveInf(strings.ToLower(strconv.FormatFloat(f, 'g', p, 64)))
fun := func(r rune) bool {
return !unicode.IsDigit(r)
}
if i := strings.IndexFunc(s, fun); i == -1 {
s += ".0"
}
return s
}
func unsignPositiveInf(s string) string {
if s == "+inf" {
return "inf"
}
return s
}
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