Manual Reference Pages - split2020 (3m_strings)
NAME
split2020(3f) - [M_strings:TOKENS] parse a string into tokens using proposed f2023 method (LICENSE:PD)
CONTENTS
Synopsis
Description
Options
Examples
Author
License
Version
SYNOPSIS
TOKEN form
subroutine split2020 (string, set, tokens, separator) character(len=*),intent(in) :: string character(len=*),intent(in) :: set character(len=:),allocatable,intent(out) :: tokens(:) character(len=1),allocatable,intent(out),optional :: separator(:)BOUNDS ARRAY form
subroutine split2020 (string, set, first, last) character(len=*),intent(in) :: string character(len=*),intent(in) :: set integer,allocatable,intent(out) :: first(:) integer,allocatable,intent(out) :: last(:)STEP THROUGH BY POSITION form
subroutine split2020 (string, set, pos [, back]) character(len=*),intent(in) :: string character(len=*),intent(in) :: set integer,intent(inout) :: pos logical,intent(in),optional :: back
DESCRIPTION
Parse a string into tokens. STRING, SET, TOKENS and SEPARATOR must all be of the same CHARACTER kind type parameter.
OPTIONS
STRING string to break into tokens SET Each character in SET is a token delimiter. A sequence of zero or more characters in STRING delimited by any token delimiter, or the beginning or end of STRING, comprise a token. Thus, two consecutive token delimiters in STRING, or a token delimiter in the first or last character of STRING, indicate a token with zero length. ??? how about if null defaults to all whitespace characters
TOKENS It is allocated with the lower bound equal to one and the upper bound equal to the number of tokens in STRING, and with character length equal to the length of the longest token. The tokens in STRING are assigned by intrinsic assignment, in the order found, to the elements of TOKENS, in array element order. ???If input is null it still must be of size 1?
SEPARATOR Each element in SEPARATOR(i) is assigned the value of the ith token delimiter in STRING. It is allocated with the lower bound equal to one and the upper bound equal to one less than the number of tokens in STRING, and with character length equal to one. ???one less than? ’’ ’ ’
FIRST It is allocated with the lower bound equal to one and the upper bound equal to the number of tokens in STRING. Each element is assigned, in array element order, the starting position of each token in STRING, in the order found. If a token has zero length, the starting position is equal to one if the token is at the beginning of STRING, and one greater than the position of the preceding delimiter otherwise. LAST It is allocated with the lower bound equal to one and the upper bound equal to the number of tokens in STRING. Each element is assigned, in array element order, the ending position of each token in STRING, in the order found. If a token has zero length, the ending position is one less than the starting position. POS If BACK is present with the value .TRUE., the value If BACK is absent or is present with the value .FALSE., POS is assigned the position of the leftmost token delimiter in STRING whose position is greater than POS, or if there is no such character, it is assigned a value one greater than the length of STRING. This identifies a token with starting position one greater than the value of POS on invocation, and ending position one less than the value of POS on return.
of POS shall be in the range 0 < POS LEN (STRING)+1; otherwise it shall be in the range 0 POS LEN (STRING). If BACK is present with the value true, POS is assigned the position of the rightmost token delimiter in STRING whose position is less than POS, or if there is no such character, it is assigned the value zero. This identifies a token with ending position one less than the value of POS on invocation, and starting position one greater than the value of POS on return.
When SPLIT is invoked with a value for POS of 1 <= POS <= LEN(STRING) and STRING(POS:POS) is not a token delimiter present in SET, the token identified by SPLIT does not comprise a complete token as described in the description of the SET argument, but rather a partial token.
BACK shall be a logical scalar. It is an INTENT (IN) argument. If POS does not appear and BACK is present with the value true, STRING is scanned backwards for tokens starting from the end. If POS does not appear and BACK is absent or present with the value false, STRING is scanned forwards for tokens starting from the beginning.
EXAMPLES
Sample of uses
program demo_sort2020 use M_strings, only : split2020 implicit none character(len=*),parameter :: gen=’(*("[",g0,"]":,","))’Results:! Execution of TOKEN form block character (len=:), allocatable :: string character (len=:), allocatable :: tokens(:) character (len=*),parameter :: set = " ," string = ’first,second,third’ call split2020(string, set, tokens ) write(*,gen)tokens
! assigns the value [’first ’,’second’,’third ’ ] ! to TOKENS. endblock
! Execution of BOUNDS form
block character (len=:), allocatable :: string character (len=*),parameter :: set = " ," integer, allocatable :: first(:), last(:) string = ’first,second,,forth’ call split2020 (string, set, first, last) write(*,gen)first write(*,gen)last
! will assign the value [ 1, 7, 14, 15 ] to FIRST, ! and the value [ 5, 12, 13, 19 ] to LAST. endblock
! Execution of STEP form block character (len=:), allocatable :: string character (len=*),parameter :: set = " ," integer :: p, ibegin, iend string = " one, last example " do while (p < len(string)) ibegin = p + 1 call split2020 (string, set, p) iend=p-1 if(iend > ibegin)then print ’(t3,a,1x,i0,1x,i0)’, string (ibegin:iend),ibegin,iend endif enddo endblock end program demo_sort2020
[first ],[second],[third ] [1],[7],[14],[15] [5],[12],[13],[19] one 2 4 last 9 12 example 15 21> ??? option to skip adjacent delimiters (not return null tokens) > common with whitespace > ??? quoted strings, especially CSV both " and ’, Fortran adjacent > is insert versus other rules > ??? escape character like \\ . > ??? multi-character delimiters like \\n, \\t, > ??? regular expression separator
AUTHOR
Milan Curcic, "milancurcic@hey.com"
LICENSE
MIT
VERSION
version 0.1.0, copyright 2020, Milan Curcic
| Nemo Release 3.1 | split2020 (3m_strings) | January 10, 2025 |
