application of fprettify, 2/2

For easier reading of git's reflogs and diff views, some lines
were manually edited/truncated.  The test and reference arrays
in check.f90 were protected by "fprettify fences" to retain some
visual guide; the additional white space does not affect the
result of fpm test, nor the diff test launched by the Makefile.
For the present project, with editors with syntax highlighting,
I'm not sure if an horizontal alignment of variable declarations
(and not only around `::`, as discussed on fprettify[1]) is of
significant advantage here.

[1] fortran-lang/fprettify#157

Signed-off-by: Norwid Behrnd <nbehrnd@yahoo.com>

app/main.f90

@@ -16,7 +16,7 @@
 ! If not, see <http://www.gnu.org/licenses/>.
 !------------------------------------------------------------------------------
 ! Contributed by Vincent Magnin, 2006-11-27; Norwid Behrnd, 2023
-! Last modifications: 2023-09-05
+! Last modifications: 2023-09-12
 !------------------------------------------------------------------------------
 
 program main
@@ -25,11 +25,11 @@ program main
 
   implicit none
   ! Variables locales :
-  integer, dimension(9, 9) :: grid    ! (line, column)
-  real(kind=dp) :: Start, End ! monitor the duration of computation
+  integer, dimension(9, 9) :: grid
+  real(kind=dp) :: Start, End  ! monitor the duration of computation
   integer :: choice
-  integer :: n_empty    ! number of cells to clear
-  character(50) :: file   ! file name (including extension .txt)
+  integer :: n_empty  ! number of cells to clear
+  character(50) :: file  ! file name (including extension .txt)
 
   select case (command_argument_count())
   case (0) ! the typical invocation with `fpm run`
@@ -40,7 +40,7 @@ program main
     grid = 0
 
     print *, "sudoku.f90, version 0.8.1, copyright (C) 2006 Vincent MAGNIN"
-    ! provide a user menue
+    ! provide a user menu
     do
       print *
       print *, "*************************** MENU *****************************************"

src/sudoku.f90

@@ -16,7 +16,7 @@
 ! If not, see <http://www.gnu.org/licenses/>.
 !------------------------------------------------------------------------------
 ! Contributed by Vincent Magnin, 2006-11-27; Norwid Behrnd, 2023
-! Last modifications: 2023-09-05
+! Last modifications: 2023-09-12
 !------------------------------------------------------------------------------
 
 module sudoku
@@ -29,14 +29,14 @@ subroutine Solve_grid(grid)
     ! input/output parameters:
     integer, dimension(9, 9), intent(inout) :: grid
     ! local variables:
-    integer, dimension(9, 9) :: grid_0        !
-    real(kind=dp) :: random        ! random number
+    integer, dimension(9, 9) :: grid_0  ! empty grid
+    real(kind=dp) :: random  ! random number
     integer :: row, column, line_0, row_0, i, j
-    integer :: counter_empty_cells    ! counter of empty/non allocated cells
-    integer, dimension(1:81, 1:3) :: empty_cells    ! list of empty cells
-    !logical, dimension(0:9)     :: possible    ! Possibility of each number
-    integer, dimension(1:9) :: possible_digit    ! list of (still) possible numbers
-    integer :: counter_possible_digits    ! counter of possible numbers
+    integer :: counter_empty_cells  ! counter of empty/non allocated cells
+    integer, dimension(1:81, 1:3) :: empty_cells  ! list of empty cells
+    ! logical, dimension(0:9)     :: possible    ! Possibility of each number
+    integer, dimension(1:9) :: possible_digit  ! list of (still) possible numbers
+    integer :: counter_possible_digits  ! counter of possible numbers
 
     possible_digit = 0
 
@@ -53,13 +53,14 @@ subroutine Solve_grid(grid)
           counter_empty_cells = counter_empty_cells + 1
           empty_cells(counter_empty_cells, 1) = row
           empty_cells(counter_empty_cells, 2) = column
-          !call list_possible_digits(grid,row,column,empty_cells(counter_empty_cells,3),possible_digit)
+          ! call list_possible_digits(grid, row, column, &
+          ! empty_cells(counter_empty_cells,3), possible_digit)
         end if
       end do
     end do
 
     ! sort the empty cells:
-    !call Draw(empty_cells,1,counter_empty_cells)
+    ! call Draw(empty_cells,1,counter_empty_cells)
 
     ! iterate over all empty cells:
     i = 1
@@ -70,7 +71,8 @@ subroutine Solve_grid(grid)
       do j = i, counter_empty_cells
         line_0 = empty_cells(j, 1)
         row_0 = empty_cells(j, 2)
-        call list_possible_digits(grid, line_0, row_0, empty_cells(j, 3), possible_digit)
+        call list_possible_digits(grid, line_0, row_0, &
+                                  empty_cells(j, 3), possible_digit)
       end do
       ! retrieve the empty cells (which depends on the number of still
       ! possible numbers)
@@ -80,7 +82,8 @@ subroutine Solve_grid(grid)
       line_0 = empty_cells(i, 1)
       row_0 = empty_cells(i, 2)
 
-      call list_possible_digits(grid, line_0, row_0, counter_possible_digits, possible_digit)
+      call list_possible_digits(grid, line_0, row_0, &
+                                counter_possible_digits, possible_digit)
 
       ! if there are multiple possibilities, choose one (by chance) and
       ! continue with the next empty cell:
@@ -103,16 +106,17 @@ subroutine Solve_grid(grid)
   end subroutine Solve_grid
 
   ! procedure to create a list of allowed numbers in the present empty cell:
-  subroutine list_possible_digits(grid, line_0, row_0, counter_possible_digits, possible_digit)
+  subroutine list_possible_digits(grid, line_0, row_0, &
+                                  counter_possible_digits, possible_digit)
     ! input parameters:
     integer, dimension(9, 9), intent(in) :: grid
     integer :: line_0, row_0
     ! output parameters:
-    integer, dimension(1:9), intent(out) :: possible_digit    ! list of possible numbers
-    integer, intent(out) :: counter_possible_digits        ! counter of possible numbers
+    integer, dimension(1:9), intent(out) :: possible_digit
+    integer, intent(out) :: counter_possible_digits
     ! locale variables:
     integer :: row, column, cr, lr, j
-    logical, dimension(0:9) :: possible    ! Possibility of each number
+    logical, dimension(0:9) :: possible  ! Plausibility of each digit
 
     possible = .true.
     do j = 1, 9
@@ -136,7 +140,7 @@ subroutine list_possible_digits(grid, line_0, row_0, counter_possible_digits, po
         possible_digit(counter_possible_digits) = j
       end if
     end do
-  end subroutine
+  end subroutine list_possible_digits
 
   !****************************************************************
   ! Starting from position p, sort the (still) empty cells by
@@ -148,11 +152,10 @@ subroutine Draw(empty_cells, p, n)
     integer, intent(in) :: n    ! number of empty lists
     integer, intent(in) :: p    ! sort, start by position p (p inclusive)
     ! output parameters:
-    integer, dimension(1:81, 1:3), intent(inout) :: empty_cells    ! list of empty cells
+    integer, dimension(1:81, 1:3), intent(inout) :: empty_cells
     ! local variables:
-    integer :: i    ! loop counters
-    integer :: j
-    integer, dimension(1:3) :: column    ! save
+    integer :: i, j ! loop counters
+    integer, dimension(1:3) :: column
     logical :: completely_solved
 
     completely_solved = .false.
@@ -224,8 +227,9 @@ logical function ValidDigit(grid, row, column)
     i = (row - 1) / 3
     j = (column - 1) / 3
 
-    ValidDigit = ValidColumOrRow(grid(row, 1:9)) .and. ValidColumOrRow(grid(1:9, column)) &
-        & .and. ValidZone(grid(i * 3 + 1:i * 3 + 3, j * 3 + 1:j * 3 + 3))
+    ValidDigit = ValidColumOrRow(grid(row, 1:9)) .and. &
+                 ValidColumOrRow(grid(1:9, column)) .and. &
+                 ValidZone(grid(i * 3 + 1:i * 3 + 3, j * 3 + 1:j * 3 + 3))
   end function ValidDigit
 
   ! Note: at present it is unknown if there are Sudoku grids with less than
@@ -303,7 +307,7 @@ subroutine Save_grid(grid, filename)
     open (newunit=fileunit, file=filename, STATUS="REPLACE")
 
     do row = 1, 9
-      write (fileunit, '(3i2, " |", 3i2, " |", 3i2)') (grid(row, column), column=1, 9)
+      write (fileunit, '(3I2, " |", 3I2, " |", 3I2)') (grid(row, column), column=1, 9)
       if ((row == 3) .or. (row == 6)) then
         write (fileunit, *) "------+-------+------"
       end if
@@ -330,7 +334,7 @@ subroutine Read_grid(grid, filename)
     open (newunit=fileunit, file=filename)
 
     do row = 1, 9
-      READ (fileunit, '(3i2, a2, 3i2, a2, 3i2)') &
+      READ (fileunit, '(3I2, A2, 3I2, A2, 3I2)') &
         grid(row, 1:3), pipe1, grid(row, 4:6), pipe2, grid(row, 7:9)
 
       ! skip the lines of dashes
@@ -347,7 +351,7 @@ subroutine Display_grid(grid)
     integer :: row, column  ! line numbers and column numbers
 
     do row = 1, 9
-      print '(3i2, " |", 3i2, " |", 3i2)', (grid(row, column), column=1, 9)
+      print '(3I2, " |", 3I2, " |", 3I2)', (grid(row, column), column=1, 9)
       if ((row == 3) .or. (row == 6)) then
         print *, "------+-------+------"
       end if
@@ -370,8 +374,8 @@ logical function ValidColumOrRow(col)
     ! input parameter:
     integer, dimension(1:9) :: col
     ! local variables:
-    integer, dimension(0:9) :: counter    ! count the occurrence of each number
-    integer :: row        ! loop counter
+    integer, dimension(0:9) :: counter  ! count the occurrence of each number
+    integer :: row
 
     ValidColumOrRow = .true.
     counter = 0
@@ -480,7 +484,7 @@ end function Time
 
   subroutine solver(grid, file)
     ! ******************************************************************
-    ! proempty a solution for a partially filled grid proemptyd as a file
+    ! provide a solution for a partially filled grid entered as a file
     !
     ! Concept study for a direct invocation of the executable by the CLI
     ! as, for example, by

test/check.f90

@@ -1,6 +1,6 @@
 ! file:  check.f90
 ! date:  [2023-08-24 Thu]
-! edit:  [2023-09-05 Tue]
+! edit:  [2023-09-12 Tue]
 
 ! This file contains tests to be launched by `fpm test`.
 
@@ -22,17 +22,19 @@ subroutine assert_readtest01()
 
     array_equality = .true.
 
-    reference_grid(:, 1) = [5, 3, 0, 0, 7, 0, 0, 0, 0]
-    reference_grid(:, 2) = [6, 0, 0, 1, 9, 5, 0, 0, 0]
-    reference_grid(:, 3) = [0, 9, 8, 0, 0, 0, 0, 6, 0]
+    !&<
+    reference_grid(:, 1) = [5, 3, 0,  0, 7, 0,  0, 0, 0]
+    reference_grid(:, 2) = [6, 0, 0,  1, 9, 5,  0, 0, 0]
+    reference_grid(:, 3) = [0, 9, 8,  0, 0, 0,  0, 6, 0]
 
-    reference_grid(:, 4) = [8, 0, 0, 0, 6, 0, 0, 0, 3]
-    reference_grid(:, 5) = [4, 0, 0, 8, 0, 3, 0, 0, 1]
-    reference_grid(:, 6) = [7, 0, 0, 0, 2, 0, 0, 0, 6]
+    reference_grid(:, 4) = [8, 0, 0,  0, 6, 0,  0, 0, 3]
+    reference_grid(:, 5) = [4, 0, 0,  8, 0, 3,  0, 0, 1]
+    reference_grid(:, 6) = [7, 0, 0,  0, 2, 0,  0, 0, 6]
 
-    reference_grid(:, 7) = [0, 6, 0, 0, 0, 0, 2, 8, 0]
-    reference_grid(:, 8) = [0, 0, 0, 4, 1, 9, 0, 0, 5]
-    reference_grid(:, 9) = [0, 0, 0, 0, 8, 0, 0, 7, 9]
+    reference_grid(:, 7) = [0, 6, 0,  0, 0, 0,  2, 8, 0]
+    reference_grid(:, 8) = [0, 0, 0,  4, 1, 9,  0, 0, 5]
+    reference_grid(:, 9) = [0, 0, 0,  0, 8, 0,  0, 7, 9]
+    !&>
 
     call Read_grid(grid_from_file, "./test/test_in_01.txt")
     grid_from_file = transpose(grid_from_file)
@@ -65,17 +67,19 @@ subroutine assert_readtest02()
 
     array_equality = .true.
 
-    reference_grid(:, 1) = [5, 3, 0, 0, 7, 0, 0, 0, 0]
-    reference_grid(:, 2) = [6, 0, 0, 1, 9, 5, 0, 0, 0]
-    reference_grid(:, 3) = [0, 9, 8, 0, 0, 0, 0, 6, 0]
+    !&<
+    reference_grid(:, 1) = [5, 3, 0,  0, 7, 0,  0, 0, 0]
+    reference_grid(:, 2) = [6, 0, 0,  1, 9, 5,  0, 0, 0]
+    reference_grid(:, 3) = [0, 9, 8,  0, 0, 0,  0, 6, 0]
 
-    reference_grid(:, 4) = [8, 0, 0, 0, 6, 0, 0, 0, 3]
-    reference_grid(:, 5) = [4, 0, 0, 8, 0, 3, 0, 0, 1]
-    reference_grid(:, 6) = [7, 0, 0, 0, 2, 0, 0, 0, 6]
+    reference_grid(:, 4) = [8, 0, 0,  0, 6, 0,  0, 0, 3]
+    reference_grid(:, 5) = [4, 0, 0,  8, 0, 3,  0, 0, 1]
+    reference_grid(:, 6) = [7, 0, 0,  0, 2, 0,  0, 0, 6]
 
-    reference_grid(:, 7) = [0, 6, 0, 0, 0, 0, 2, 8, 0]
-    reference_grid(:, 8) = [0, 0, 0, 4, 1, 9, 0, 0, 5]
-    reference_grid(:, 9) = [0, 0, 0, 0, 8, 0, 0, 7, 9]
+    reference_grid(:, 7) = [0, 6, 0,  0, 0, 0,  2, 8, 0]
+    reference_grid(:, 8) = [0, 0, 0,  4, 1, 9,  0, 0, 5]
+    reference_grid(:, 9) = [0, 0, 0,  0, 8, 0,  0, 7, 9]
+    !&>
 
     call Read_grid(grid_from_file, "./test/test_in_02.txt")
     grid_from_file = transpose(grid_from_file)
@@ -110,32 +114,36 @@ subroutine assert_wikipedia_solution()
     array_equality = .true.
 
     ! Wikipedia's incomplete Sudoku grid
-    grid_a(:, 1) = [5, 3, 0, 0, 7, 0, 0, 0, 0]
-    grid_a(:, 2) = [6, 0, 0, 1, 9, 5, 0, 0, 0]
-    grid_a(:, 3) = [0, 9, 8, 0, 0, 0, 0, 6, 0]
+    !&<
+    grid_a(:, 1) = [5, 3, 0,  0, 7, 0,  0, 0, 0]
+    grid_a(:, 2) = [6, 0, 0,  1, 9, 5,  0, 0, 0]
+    grid_a(:, 3) = [0, 9, 8,  0, 0, 0,  0, 6, 0]
 
-    grid_a(:, 4) = [8, 0, 0, 0, 6, 0, 0, 0, 3]
-    grid_a(:, 5) = [4, 0, 0, 8, 0, 3, 0, 0, 1]
-    grid_a(:, 6) = [7, 0, 0, 0, 2, 0, 0, 0, 6]
+    grid_a(:, 4) = [8, 0, 0,  0, 6, 0,  0, 0, 3]
+    grid_a(:, 5) = [4, 0, 0,  8, 0, 3,  0, 0, 1]
+    grid_a(:, 6) = [7, 0, 0,  0, 2, 0,  0, 0, 6]
 
-    grid_a(:, 7) = [0, 6, 0, 0, 0, 0, 2, 8, 0]
-    grid_a(:, 8) = [0, 0, 0, 4, 1, 9, 0, 0, 5]
-    grid_a(:, 9) = [0, 0, 0, 0, 8, 0, 0, 7, 9]
+    grid_a(:, 7) = [0, 6, 0,  0, 0, 0,  2, 8, 0]
+    grid_a(:, 8) = [0, 0, 0,  4, 1, 9,  0, 0, 5]
+    grid_a(:, 9) = [0, 0, 0,  0, 8, 0,  0, 7, 9]
+    !&>
 
     call Solve_grid(grid_a) ! this fills (hence modifies) grid_a
 
     ! Wikipedia's complete Sudoku grid
-    grid_b(:, 1) = [5, 3, 4, 6, 7, 8, 9, 1, 2]
-    grid_b(:, 2) = [6, 7, 2, 1, 9, 5, 3, 4, 8]
-    grid_b(:, 3) = [1, 9, 8, 3, 4, 2, 5, 6, 7]
-
-    grid_b(:, 4) = [8, 5, 9, 7, 6, 1, 4, 2, 3]
-    grid_b(:, 5) = [4, 2, 6, 8, 5, 3, 7, 9, 1]
-    grid_b(:, 6) = [7, 1, 3, 9, 2, 4, 8, 5, 6]
-
-    grid_b(:, 7) = [9, 6, 1, 5, 3, 7, 2, 8, 4]
-    grid_b(:, 8) = [2, 8, 7, 4, 1, 9, 6, 3, 5]
-    grid_b(:, 9) = [3, 4, 5, 2, 8, 6, 1, 7, 9]
+    !&<
+    grid_b(:, 1) = [5, 3, 4,  6, 7, 8,  9, 1, 2]
+    grid_b(:, 2) = [6, 7, 2,  1, 9, 5,  3, 4, 8]
+    grid_b(:, 3) = [1, 9, 8,  3, 4, 2,  5, 6, 7]
+
+    grid_b(:, 4) = [8, 5, 9,  7, 6, 1,  4, 2, 3]
+    grid_b(:, 5) = [4, 2, 6,  8, 5, 3,  7, 9, 1]
+    grid_b(:, 6) = [7, 1, 3,  9, 2, 4,  8, 5, 6]
+
+    grid_b(:, 7) = [9, 6, 1,  5, 3, 7,  2, 8, 4]
+    grid_b(:, 8) = [2, 8, 7,  4, 1, 9,  6, 3, 5]
+    grid_b(:, 9) = [3, 4, 5,  2, 8, 6,  1, 7, 9]
+    !&>
 
     ! comparison of computed solution with Wikipedia's reference solution
     outer: do i = 1, 9