package math
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import (
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"errors"
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"math"
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)
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var ErrOverflowInt32 = errors.New("int32 overflow")
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var ErrOverflowUint8 = errors.New("uint8 overflow")
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var ErrOverflowInt8 = errors.New("int8 overflow")
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// SafeAddInt32 adds two int32 integers.
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func SafeAddInt32(a, b int32) (int32, error) {
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if b > 0 && (a > math.MaxInt32-b) {
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return 0, ErrOverflowInt32
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} else if b < 0 && (a < math.MinInt32-b) {
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return 0, ErrOverflowInt32
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}
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return a + b, nil
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}
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// SafeSubInt32 subtracts two int32 integers.
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func SafeSubInt32(a, b int32) (int32, error) {
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if b > 0 && (a < math.MinInt32+b) {
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return 0, ErrOverflowInt32
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} else if b < 0 && (a > math.MaxInt32+b) {
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return 0, ErrOverflowInt32
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}
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return a - b, nil
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}
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// SafeConvertInt32 takes a int and checks if it overflows.
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func SafeConvertInt32(a int64) (int32, error) {
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if a > math.MaxInt32 {
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return 0, ErrOverflowInt32
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} else if a < math.MinInt32 {
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return 0, ErrOverflowInt32
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}
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return int32(a), nil
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}
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// SafeConvertUint8 takes an int64 and checks if it overflows.
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func SafeConvertUint8(a int64) (uint8, error) {
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if a > math.MaxUint8 {
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return 0, ErrOverflowUint8
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} else if a < 0 {
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return 0, ErrOverflowUint8
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}
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return uint8(a), nil
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}
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// SafeConvertInt8 takes an int64 and checks if it overflows.
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func SafeConvertInt8(a int64) (int8, error) {
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if a > math.MaxInt8 {
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return 0, ErrOverflowInt8
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} else if a < math.MinInt8 {
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return 0, ErrOverflowInt8
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}
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return int8(a), nil
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}
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