M409: Concentrate and Disperse Character Strings

Author(s): J. Zoll	Library: KERNLIB
Submitter:	Submitted: 01.03.1968
Language: Fortran or Assembler	Revised: 09.09.1991

The concept string of n Hollerith characters is machine independent, but its usual representation in Am format (with m = character capacity of a machine word: A10, A8, A6, A4) is not.

Supposing any computer to have a character capacity of at least A4, string representations in A4, A3, A2 or A1 are transportable. Representations A1 and A4 are particularly interesting.

Fortran 77 defines a new data type CHARACTER though most compilers also support Hollerith strings (without a clear definition of the differences). A set of routines has been added to this package in its Fortran 77 implementation to convert between CHARACTER strings and Hollerith strings.

The routines UBLOW, UBUNCH and UTRANS work on Hollerith only and so should be considered obsolete, while UCTOH, UCTOH1 and UHTOC and UH1TOC copy between CHARACTER and Hollerith. Unpredictable results will be obtained if wrong data types are passed to these routines. On most machines text strings passed in quotes are implicitly of type CHARACTER while a string preceeded by nH is not.

The routines of this package perform transformations between different representations.

Structure:

SUBROUTINE subprograms
User Entry Names: UBUNCH, UBLOW, UTRANS, UCTOH, UCTOH1, UHTOC, UH1TOC
COMMON Block Names and Lengths: /SLATE/ NI,NJ,DUMMY(38)

Usage:

    CALL UBLOW(IVM,IV1,NCH)

disperses the string of NCH Hollerith characters from IVM into IV1.

IVM

Input vector, continuous string of NCH Hollerith characters in Am form (i.e. A10, A8 or A4 depending on the machine).

IV1

Output vector, NCH words in A1 form, i.e. a single Hollerith character per word with blank-fill.

NCH

Number of Hollerith characters to be copied.

    CALL UBUNCH(IV1,IVM,NCH)

concentrates the string of NCH Hollerith characters from IV1 into IVM.

IV1

Input vector, NCH words in A1 form (one Hollerith character per word).

IVM

Output vector, continuous string of NCH Hollerith characters in Am form (i.e. A10, A8 or A4 depending on the machine), with blank-fill of trailing characters in the last word, if any.

NCH

Number of Hollerith characters to be copied.

    CALL UTRANS(IVI,IVJ,NCH,I,J)

copies the string of NCH Hollerith characters from IVI into IVJ.

IVI

Input vector of NCH Hollerith characters with I characters per machine word in Ai form. The variable NI in /SLATE/ is set to the number of machine words used from IVI.

IVJ

Output vector of NCH Hollerith characters with J characters per machine word in Aj form, with blank-fill. The variable NJ in /SLATE/ is set to the number of machine words built in IVJ.

NCH

Number of Hollerith characters to be copied.

I,J

Number of Hollerith characters per word in IVI and IVJ. If either I or J is greater than the maximum possible number of characters storable in a machine word then this maximum is used instead.

    CALL UCTOH(MCH,IVJ,J,NCH)

copies the CHARACTER-type string in MCH into Hollerith characters in IVJ in Aj form.

MCH

Input vector of NCH characters, either of type CHARACTER or of type INTEGER holding Hollerith in Am form.

IVJ

Output vector of NCH Hollerith characters with J characters per machine word in Aj form, with blank-fill.

J

Number of Hollerith characters to put in each word of IVJ. If J is larger than the maximum possible number of Hollerith characters per word this maximum will be used instead.

NCH

Number of characters to copy.

    CALL UCTOH1(MCH,IV1,NCH)

disperses the CHARACTER-type string in MCH into Hollerith characters in IV1 in A1 form.

MCH

Input vector of NCH characters, either of type CHARACTER or of type INTEGER holding Hollerith in Am form.

IV1

Output vector, NCH words in A1 form, i.e. a single Hollerith character per word with blank-fill.

NCH

Total number of characters to copy.

    CALL UHTOC(IVI,I,CHV,NCH)

copies the Hollerith characters in IVI into the CHARACTER variable CHV.

IVI

Input vector of NCH Hollerith characters with I characters stored per word in Ai form.

I

Number of Hollerith characters to take from each word of IVI. If I is larger than the maximum possible number of Hollerith characters per word this maximum will be used instead.

CHV

Output variable of type CHARACTER to receive NCH characters.

NCH

Number of characters to copy. If the CHARACTER variable CHV is of length greater than NCH trailing characters will not be changed.

    CALL UH1TOC(IV1,CHV,NCH)

concentrates a Hollerith string in A1 form into the CHARACTER variable CHV.

IV1

Input vector of NCH words containing one Hollerith character each in A1 form.

CHV

Output variable of type CHARACTER to receive NCH characters.

NCH

Total number of characters to copy. If the variable CHV is of length greater than NCH trailing characters will not be changed.

Error handling:

acts as do-nothing.

Examples:

(b = blank).

1)    CALL UBLOW(11HABCDEFGHIJK,V,11)

fills V: , with blank padding of each word.

2)    CALL UBUNCH(V,X,11)

gives the inverse transformation, thus on the CDC 7600 :

      X(1) = 10ABCDEFGHIJ, X(2) = 10HKbbbbbbbb

3)    CALL UTRANS(X,Y,11,99,4)

copies the continuous X string to A4 representation in Y:

      Y(1) = 4HABCD, Y(2) = 4HEFGH, Y(3) = 4HIJKb

with blank padding if .

4)    CALL UTRANS(Y,X,11,4,99)

gives the inverse of example 3).

5)    CALL UTRANS(V,X,11,1,99)

gives the same result as example 2), but is much slower.

6)    DIMENSION V(4)
      CHARACTER*14 C/'THIS IS A TEST'/
      CALL UCTOH(C,V,4,14)

copies the CHARACTER string in C into V such that

      V(1) = 4HTHIS, V(2) = 4HbISb, V(3) = 4HAbTE, V(4) = 4HSTbb

7)    DIMENSION V(4)
      CHARACTER*14 C
      DATA V /14HTHIS IS A TEST/   or   DATA V /4HTHIS,4H IS ,4HA TE,2HST/
      CALL UHTOC(V,4,C,14)

copies the Hollerith strings in V into C such that C='THIS IS A TEST'.

8)    DIMENSION V(4)
      CHARACTER*4 C/'TEST'/
      CALL UCTOH1(C,V,4)

copies the CHARACTER-string in C into V such that

      V(1) = 4HTbbb, V(2) = 4HEbbb, V(3) = 4HSbbb, V(4) = 4HTbbb

9)    DIMENSION V(4)
      CHARACTER*4 C
      DATA V/1HT,1HE,1HS,1HT/
      CALL UH1TOC(V,C,4)

copies the Hollerith characters in V into the CHARACTER string C such that C='TEST'.