Node:Lisp Number Operations, Previous:Lisp support, Up:Lisp support

Lisp Number Operations

(Section numbers refer to: Guy Steel jr. "Common Lisp: The Language", second edition, 1990.)

The "Predicates on Numbers" (from Section 12.2) are all implemented.

zerop number

Function

True if number is zero.

plusp number

Function

True if number is positive

minusp number

Function

True of number is negative

oddp integer

Function

True if integer is odd.

evenp integer

Function

True if integer is even.

The "Logical Operations on Numbers" (from Section 12.7) are all implemented. These all consider an integer as a semi-infinite bit string.

logior &rest integers

Function

Take the "inclusive or" of the integers.

logxor &rest integers

Function

Take the "exclusive or" of the integers.

logand &rest integers

Function

Take the logical "and" of the integers.

logeqv &rest integers

Function

Take the "exclusive nor" (bit-wise logival equivalence) of the integers.

lognand integer1 integer2

Function

Same as (lognot (logand integer1 integer2)).

lognor integer1 integer2

Function

Same as (lognot (logor integer1 integer2)).

logandc1 integer1 integer2

Function

Same as (logand (lognot integer1) integer2).

logandc1 integer1 integer2

Function

Same as (logand (lognot integer1) integer2).

logandc2 integer1 integer2

Function

Same as (logand integer1 (lognot integer2)).

logorc1 integer1 integer2

Function

Same as (logor (lognot integer1) integer2).

logorc2 integer1 integer2

Function

Same as (logor integer1 (lognot integer2)).

boole operation integer1 integer2

Function

Does the bit-wise boolean operation indicated by operation, on the two operands integer1 and integer2. The operation is one of the 16 constants below.

boole-clr

Constant

boole-set

Constant

boole-1

Constant

boole-2

Constant

boole-c1

Constant

boole-c2

Constant

boole-and

Constant

boole-ior

Constant

boole-xor

Constant

boole-eqv

Constant

boole-nand

Constant

boole-nor

Constant

boole-andc1

Constant

boole-andc2

Constant

boole-orc1

Constant

boole-orc2

Constant

lognot integer

Function

Returns the bit-wise logical "not" of integer.

logtest integer1 integer2

Function

Same as (not (zerop (logand integer1 integer2))).

logbitp index integer

Function

True iff bit number index in integer is one.

ash integer count

Function

Does an arithmetic shift by count on integer. Shift left is count is positive; otherwise, shift right.

logcount integer

Function

Count the number of 1-bits in integer, if it is non-negative. If integer is negative, count number of 0-bits.

integer-count integer

Function

Return number of bits needed to represent integer.