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Index of and Membership Symbol Processing Functions

IP.com Disclosure Number: IPCOM000079995D
Original Publication Date: 1973-Oct-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 11K

Publishing Venue

IBM

Related People

Reynolds, SW: AUTHOR

Abstract

THE TWO PRINCIPAL FUNCTIONS, WXOF (WORD INDEX OF) AND WMEMBER (WORD MEMBER), OPERATE ON PROPER FILES IN A MANNER ANALOGOUS TO THE INDEX OF (A, B) AND MEMBERSHIP (A c B) PRIMITIVES OF APL, AS THEY OPERATE ON EITHER NUMERIC OR CHARACTER VECTORS.

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Index of and Membership Symbol Processing Functions

THE TWO PRINCIPAL FUNCTIONS, WXOF (WORD INDEX OF) AND WMEMBER (WORD MEMBER), OPERATE ON PROPER FILES IN A MANNER ANALOGOUS TO THE INDEX OF (A, B) AND MEMBERSHIP (A ∈ B) PRIMITIVES OF APL, AS THEY OPERATE ON EITHER NUMERIC OR CHARACTER VECTORS.

     WXOF IS UNIQUE IN THAT THE FUNCTION IS PERFORMED WITHOUT A LOOP. BOTH FUNCTIONS ARE USEFUL IN THE PROCESSING OF PROPER FILES, I.E., THOSE FILES IN WHICH EVERY SYMBOL HAS A DELIMITER FORE AND AFT. THE FUNCTIONS WORK FOR EITHER NUMERIC OR CHARACTER PROPER FILES AND WORK EITHER 0 OR 1 ORIGIN INDEXING.

     THE FUNCTION CALLED WXOF IS ANALOGOUS TO THE INDEX-OF PRIMITIVE IN APL. IF P1 AND P2 ARE PROPER NUMERIC OR CHARACTER FILES, WHERE P1 IS LEFT ARGUMENT AND P2 IS THE RIGHT ARGUMENT OF THE FUNCTION WXOF, AND IF

J<- P1 WXOF P2

THEN J IS AN INTEGER VECTOR SUCH THAT J[I] IS THE SYMBOL INDEX IN P1 OF P2 WINDEXING I. (THE SUPPORT FUNCTION WINDEXING, FOR WORD INDEXING, WAS DESCRIBED IN ARTICLES APPEARING IN THE IBM TECHNICAL DISCLOSURE BULLETIN, VOL. 16, NO. 2, JULY 1973, PAGES 537-538 AND 539-540.

FOR EXAMPLE:

(Image Omitted)

DESCRIPTION OF WXOF AND WMEMBER:

     WITHIN THE TWO PRINCIPAL FUNCTIONS WXOF AND WMEMBER, THE WORDS OF BOTH FILES P1 AND P2 ARE STRUCTURED AS MATRICES OF WORDS. ONE WORD PER ROW, WHERE BOTH MATRICES HAVE THE SAME NUMBER OF COLUMNS. LET THESE MATRICES BE CALLED MP1 AND MP2. THE MATRIX MP1 HAS THE SAME NUMBER OF ROWS AS THE FILE P1 HAS WORDS AND, SIMILARLY, MP2 SAME NUMBER OF ROWS AS P2 HAS WORDS.

     A LOGICAL MATRIX H IS FORMED BY THE INNER PRODUCT OF MP1 WITH THE TRANSPOSE OF MP2. THE STANDARD SCALAR DYADIC FUNCTIONS USED IN THE INNER PRODUCT ARE THE LOGICAL AND AND THE EQUAL. IF A WORD IN MP2 DOES NOT EXIST IN MP1, THEN H HAS A COLUMN OF ZEROES IN THE COLUMN OF H WHICH CORRESPONDS TO THAT ROW OF MP2. IF A WORD IN MP2 IS IDENT...