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|
package expr
import (
`fmt`
)
func idiv(v int64, d int64) (int64, error) {
if d != 0 {
return v / d, nil
} else {
return 0, newRuntimeError("division by zero")
}
}
func imod(v int64, d int64) (int64, error) {
if d != 0 {
return v % d, nil
} else {
return 0, newRuntimeError("division by zero")
}
}
func ipow(v int64, e int64) (int64, error) {
mul := v
ret := int64(1)
/* value must be 0 or positive */
if v < 0 {
return 0, newRuntimeError(fmt.Sprintf("negative base value: %d", v))
}
/* exponent must be non-negative */
if e < 0 {
return 0, newRuntimeError(fmt.Sprintf("negative exponent: %d", e))
}
/* fast power first round */
if (e & 1) != 0 {
ret *= mul
}
/* fast power remaining rounds */
for e >>= 1; e != 0; e >>= 1 {
if mul *= mul; (e & 1) != 0 {
ret *= mul
}
}
/* all done */
return ret, nil
}
|
