From 8425e5e2864f0cc61d3c5787cd6e306ded42a7b1 Mon Sep 17 00:00:00 2001
From: Michele Guerini Rocco <m.guerinirocco2@campus.unimib.it>
Date: Wed, 13 Sep 2023 16:47:25 +0200
Subject: [PATCH] src/gray_cli.f90: simplify argument handling

---
 src/gray_cli.f90 | 49 ++++++++++++++++++------------------------------
 1 file changed, 18 insertions(+), 31 deletions(-)

diff --git a/src/gray_cli.f90 b/src/gray_cli.f90
index 482cbda..b87bc1f 100644
--- a/src/gray_cli.f90
+++ b/src/gray_cli.f90
@@ -112,7 +112,6 @@ contains
 
     ! local variables
     character(len=:), allocatable :: argument, temp
-    logical :: skip_next = .false.
     integer :: i, nargs
     integer :: error, commas
 
@@ -123,14 +122,11 @@ contains
     opts%units       = [ucenr, usumm]
 
     nargs = command_argument_count()
-    do i = 1, nargs
-      call get_command_string(i, argument)
+    i = 1
 
-      ! skip one cycle if the last argument was a value
-      if (skip_next) then
-        skip_next = .false.
-        cycle
-      end if
+    do
+      if (i > nargs) exit
+      call get_next_command(i, argument)
 
       ! parse an argument (and possibly a value)
       select case (argument)
@@ -151,23 +147,19 @@ contains
           opts%quiet = .true.
 
         case ('-o', '--output-dir')
-          call get_command_string(i + 1, opts%output_dir)
-          skip_next = .true.
+          call get_next_command(i, opts%output_dir)
 
         case ('-p', '--params-file')
-          call get_command_string(i + 1, opts%params_file)
-          skip_next = .true.
+          call get_next_command(i, opts%params_file)
 
         case ('-c', '--config-file')
-          call get_command_string(i + 1, opts%config_file)
-          skip_next = .true.
+          call get_next_command(i, opts%config_file)
 
         case ('-s', '--sum')
-          call get_command_string(i + 1, opts%sum_filelist)
-          skip_next = .true.
+          call get_next_command(i, opts%sum_filelist)
 
         case ('-u', '--units')
-          call get_command_string(i + 1, temp)
+          call get_next_command(i, temp)
 
           ! resize the array
           commas = count([(temp(i:i) == ',', i = 1, len(temp))])
@@ -183,12 +175,11 @@ contains
             call exit(1)
           end if
           deallocate(temp)
-          skip_next = .true.
 
         case ('-g', '--gray-param')
           ! these overrides are parsed later since they need to
           ! be applied to the final gray_parameters structure
-          skip_next = .true.
+          i = i + 1
 
         case default
           print '(a,a,/)', 'Unknown option: ', argument
@@ -217,24 +208,20 @@ contains
 
     ! local variables
     character(len=:), allocatable :: argument, temp, id, val
-    logical :: skip_next = .false.
     integer :: i, nargs
     integer :: sep
 
     nargs = command_argument_count()
-    do i = 1, nargs
-      call get_command_string(i, argument)
+    i = 1
 
-      ! skip one cycle if the last argument was a value
-      if (skip_next) then
-        skip_next = .false.
-        cycle
-      end if
+    do
+      if (i > nargs) exit
+      call get_next_command(i, argument)
 
       ! parse gray parameters
       select case (argument)
         case ('-g', '--gray-param')
-          call get_command_string(i + 1, temp)
+          call get_next_command(i, temp)
 
           ! split at "=" (id=value)
           sep = index(temp, '=')
@@ -262,7 +249,6 @@ contains
           end select
 
           deallocate(temp)
-          skip_next = .true.
 
         ! skip everything else
         case default
@@ -276,13 +262,13 @@ contains
   end subroutine parse_param_overrides
 
 
-  subroutine get_command_string(i, arg)
+  subroutine get_next_command(i, arg)
     ! Reads a CLI argument into a deferred-length string
 
     implicit none
 
     ! subroutine arguments
-    integer, intent(in) :: i
+    integer, intent(inout) :: i
     character(len=:), allocatable, intent(inout) :: arg
 
     ! local variables
@@ -292,6 +278,7 @@ contains
     call get_command_argument(i, length=len) ! get the arg length
     allocate(character(len) :: arg)          ! allocate memory
     call get_command_argument(i, arg)        ! copy
+    i = i + 1                                ! increment counter
   end subroutine