Documentation
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Overview ¶
Package exact implements Values representing untyped Go constants and the corresponding operations. Values and operations have unlimited precision.
A special Unknown value may be used when a value is unknown due to an error. Operations on unknown values produce unknown values unless specified otherwise.
Index ¶
- func BitLen(x Value) int
- func BoolVal(x Value) bool
- func Bytes(x Value) []byte
- func Compare(x Value, op token.Token, y Value) bool
- func Float32Val(x Value) (float32, bool)
- func Float64Val(x Value) (float64, bool)
- func Int64Val(x Value) (int64, bool)
- func Sign(x Value) int
- func StringVal(x Value) string
- func Uint64Val(x Value) (uint64, bool)
- type Kind
- type Value
- func BinaryOp(x Value, op token.Token, y Value) Value
- func Denom(x Value) Value
- func Imag(x Value) Value
- func MakeBool(b bool) Value
- func MakeFloat64(x float64) Value
- func MakeFromBytes(bytes []byte) Value
- func MakeFromLiteral(lit string, tok token.Token) Value
- func MakeImag(x Value) Value
- func MakeInt64(x int64) Value
- func MakeString(s string) Value
- func MakeUint64(x uint64) Value
- func MakeUnknown() Value
- func Num(x Value) Value
- func Real(x Value) Value
- func Shift(x Value, op token.Token, s uint) Value
- func UnaryOp(op token.Token, y Value, size int) Value
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func BitLen ¶
BitLen returns the number of bits required to represent the absolute value x in binary representation; x must be an Int or an Unknown. If x is Unknown, the result is 0.
func BoolVal ¶
BoolVal returns the Go boolean value of x, which must be a Bool or an Unknown. If x is Unknown, the result is false.
func Bytes ¶
Bytes returns the bytes for the absolute value of x in little- endian binary representation; x must be an Int.
func Compare ¶
Compare returns the result of the comparison x op y. The comparison must be defined for the operands. If one of the operands is Unknown, the result is false.
func Float32Val ¶
Float32Val is like Float64Val but for float32 instead of float64.
func Float64Val ¶
Float64Val returns the nearest Go float64 value of x and whether the result is exact; x must be numeric but not Complex, or Unknown. For values too small (too close to 0) to represent as float64, Float64Val silently underflows to 0. The result sign always matches the sign of x, even for 0. If x is Unknown, the result is (0, false).
func Int64Val ¶
Int64Val returns the Go int64 value of x and whether the result is exact; x must be an Int or an Unknown. If the result is not exact, its value is undefined. If x is Unknown, the result is (0, false).
func Sign ¶
Sign returns -1, 0, or 1 depending on whether x < 0, x == 0, or x > 0; x must be numeric or Unknown. For complex values x, the sign is 0 if x == 0, otherwise it is != 0. If x is Unknown, the result is 1.
Types ¶
type Value ¶
type Value interface {
// Kind returns the value kind; it is always the smallest
// kind in which the value can be represented exactly.
Kind() Kind
// String returns a human-readable form of the value.
String() string
// contains filtered or unexported methods
}
A Value represents a mathematically exact value of a given Kind.
func BinaryOp ¶
BinaryOp returns the result of the binary expression x op y. The operation must be defined for the operands. If one of the operands is Unknown, the result is Unknown. To force integer division of Int operands, use op == token.QUO_ASSIGN instead of token.QUO; the result is guaranteed to be Int in this case. Division by zero leads to a run-time panic.
func Denom ¶
Denom returns the denominator of x; x must be Int, Float, or Unknown. If x is Unknown, the result is Unknown, otherwise it is an Int >= 1.
func Imag ¶
Imag returns the imaginary part of x, which must be a numeric or unknown value. If x is Unknown, the result is Unknown.
func MakeFloat64 ¶
MakeFloat64 returns the numeric value for x. If x is not finite, the result is unknown.
func MakeFromBytes ¶
MakeFromBytes returns the Int value given the bytes of its little-endian binary representation. An empty byte slice argument represents 0.
func MakeFromLiteral ¶
MakeFromLiteral returns the corresponding integer, floating-point, imaginary, character, or string value for a Go literal string. The result is nil if the literal string is invalid.
func MakeImag ¶
MakeImag returns the numeric value x*i (possibly 0); x must be Int, Float, or Unknown. If x is Unknown, the result is Unknown.
func Num ¶
Num returns the numerator of x; x must be Int, Float, or Unknown. If x is Unknown, the result is Unknown, otherwise it is an Int with the same sign as x.
func Real ¶
Real returns the real part of x, which must be a numeric or unknown value. If x is Unknown, the result is Unknown.
Source Files