tdbengine.org [Function reference]

	bitand()
	bitandnot()
	bitnot()
	bitor()
	bitsum()
	bittrunc()
	clrarray()
	'DELSESSION'
	getauto()
	getmarksauto()
	high()
	inarray()
	inarraypos()
	initarray()
	nbits()
	putmarksauto()
	'SETSESSIONIDENT'
	strsort()

Statistical functions

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Topic complex

Array functions

Function

bitnot()

Short

Complement of a Bit array

Syntax

BITNOT(VAR M : TBITS[]) : INTEGER

Parameter

M : TBITS[]

Return

NBITS(M) after operation (= cardinality of M)

See also:

bitand()

bitor()

bitandnot()

Description

M is understood as a function of a (sub-)set. After execution of the function M has the characteristical function of the complement of this set (i.e. every Bit is inverted).

Example 1: BitNot + BitTrunc

VAR x : TBITS[]
InitArray(x[3])
BitSum(x)         // = 0 <>  bits 000[00000]
BitNot(x)
BitSum(x)         // = 8 <>  bits 111[11111]
BitTrunc(x,3 +1)
BitSum(x)         // = 3 <>  bits 111[00000]

Example 2: BitNot + BitTrunc 2

Sets a bit for each record of db

var x : TBits[]
InitArray(x[FileSize(db)];
BitNot(x);x[0]:=0; BitTrunc(x,FileSize(db)+1)


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