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Oct 13, 2023
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24 changes: 10 additions & 14 deletions src/stdlib_ascii.fypp
Original file line number Diff line number Diff line change
Expand Up @@ -223,31 +223,27 @@ contains
pure function char_to_lower(c) result(t)
character(len=1), intent(in) :: c !! A character.
character(len=1) :: t
integer, parameter :: wp= iachar('a')-iachar('A'), BA=iachar('A'), BZ=iachar('Z')
integer :: k
!Check whether the integer equivalent is between BA=65 and BZ=90
k = ichar(c)
if (k>=BA.and.k<=BZ) k = k + wp
t = char(k)

k = index( uppercase, c )

if ( k > 0 ) then
t = lowercase(k:k)
else
t = c
endif
end function char_to_lower

!> Returns the corresponding uppercase letter, if `c` is a lowercase
!> ASCII character, otherwise `c` itself.
pure function char_to_upper(c) result(t)
character(len=1), intent(in) :: c !! A character.
character(len=1) :: t
integer, parameter :: wp= iachar('a')-iachar('A'), la=iachar('a'), lz=iachar('z')
integer :: k
!Check whether the integer equivalent is between la=97 and lz=122
k = ichar(c)
if (k>=la.and.k<=lz) k = k - wp
t = char(k)

k = index( lowercase, c )

if ( k > 0 ) then
t = uppercase(k:k)
else
t = c
endif
end function char_to_upper

!> Convert character variable to lower case
Expand Down