C Library Functions - replace (3)

NAME

replace(3f) - [M_list] replace entry in a string array at specified position (LICENSE:PD)

Synopsis
Description
Options
Examples
Author
License

SYNOPSIS

subroutine replace(list,value,place)

   character(len=*)|doubleprecision|real|integer,intent(in) :: value
   character(len=:)|doubleprecision|real|integer,intent(in) :: list(:)
   integer, intent(out)          :: PLACE

DESCRIPTION

replace a value in an allocatable array at the specified index. Unless the array needs the string length to increase this is merely an assign of a value to an array element.
The array may be of type CHARACTER, DOUBLEPRECISION, REAL, or INTEGER. It is assumed to be sorted in descending order without duplicate values.
The value and list must be of the same type.

OPTIONS

VALUE the value to place in the array

LIST is the array.

PLACE is the subscript that the entry should be placed at

EXAMPLES

Replace key-value pairs in a dictionary

    program demo_replace
    use M_list, only  : insert, locate, replace
    ! Find if a key is in a list and insert it
    ! into the key list and value list if it is not present
    ! or replace the associated value if the key existed
    implicit none
    character(len=20)            :: key
    character(len=100)           :: val
    character(len=:),allocatable :: keywords(:)
    character(len=:),allocatable :: values(:)
    integer                      :: i
    integer                      :: place
    call update(’b’,’value of b’)
    call update(’a’,’value of a’)
    call update(’c’,’value of c’)
    call update(’c’,’value of c again’)
    call update(’d’,’value of d’)
    call update(’a’,’value of a again’)
    ! show array
    write(*,’(*(a,"==>",a,/))’)&
           &(trim(keywords(i)),trim(values(i)),i=1,size(keywords))

    call locate(keywords,’a’,place)
    if(place.gt.0)then
       write(*,*)’The value of "a" is ’,trim(values(place))
    else
       write(*,*)’"a" not found’
    endif

    contains
    subroutine update(key,val)
    character(len=*),intent(in)  :: key
    character(len=*),intent(in)  :: val
    integer                      :: place

    ! find where string is or should be
    call locate(keywords,key,place)
    ! if string was not found insert it
    if(place.lt.1)then
       call insert(keywords,key,abs(place))
       call insert(values,val,abs(place))
    else ! replace
       call replace(values,val,place)
    endif

    end subroutine update

end program demo_replace

Results

   > d==>value of d
   > c==>value of c again
   > b==>value of b
   > a==>value of a again

AUTHOR

1989,2017 John S. Urban

LICENSE

Public Domain

Nemo Release 3.1

replace (3)

February 23, 2025

Generated by manServer 1.08 from 80b0f969-a662-4217-a483-79f7815a56be using man macros.

VALUE	the value to place in the array
LIST	is the array.
PLACE	is the subscript that the entry should be placed at