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Function LOGBITP

Syntax

  • logbitp index integergeneralized-boolean

Arguments and Values

Description

logbitp is used to test the value of a particular bit in integer, that is treated as if it were binary.

The value of logbitp is true if the bit in integer whose index is index (that is, its weight is 2^index) is a one-bit; otherwise it is false.

Negative integers are treated as if they were in two's-complement notation.

Examples

(logbitp 1 1)

false

(logbitp 0 1)

true

(logbitp 3 10)

true

(logbitp 1000000 -1)

true

(logbitp 2 6)

true

(logbitp 0 6)

false

Side Effects

None.

Affected By

None.

Exceptional Situations

Should signal an error of type type-error if index is not a non-negative integer. Should signal an error of type type-error if integer is not an integer.

See Also

None.

Notes

(logbitp k n) ≡ (ldb-test (byte 1 k) n)

\issue{ARGUMENTS-UNDERSPECIFIED:SPECIFY}