34 lines
983 B
Go
34 lines
983 B
Go
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//+build !linux,!darwin,!dragonfly,!freebsd,!netbsd,!openbsd,!solaris darwin,arm64 !amd64,!arm64,!mips64x,!ppc64x
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package starlark
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// generic Int implementation as a union
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import "math/big"
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type intImpl struct {
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// We use only the signed 32-bit range of small to ensure
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// that small+small and small*small do not overflow.
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small_ int64 // minint32 <= small <= maxint32
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big_ *big.Int // big != nil <=> value is not representable as int32
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}
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// --- low-level accessors ---
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// get returns the small and big components of the Int.
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// small is defined only if big is nil.
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// small is sign-extended to 64 bits for ease of subsequent arithmetic.
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func (i Int) get() (small int64, big *big.Int) {
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return i.impl.small_, i.impl.big_
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}
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// Precondition: math.MinInt32 <= x && x <= math.MaxInt32
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func makeSmallInt(x int64) Int {
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return Int{intImpl{small_: x}}
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}
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// Precondition: x cannot be represented as int32.
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func makeBigInt(x *big.Int) Int {
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return Int{intImpl{big_: x}}
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}
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