made move subroutine of stdlib_string_type module pure

Author: aman-godara

Diff for: src/stdlib_string_type.fypp

@@ -713,7 +713,7 @@ contains
 
     !> Moves the allocated character scalar from 'from' to 'to'
     !> No output
-    subroutine move_string_string(from, to)
+    pure subroutine move_string_string(from, to)
         type(string_type), intent(inout) :: from
         type(string_type), intent(out) :: to
 
@@ -723,7 +723,7 @@ contains
 
     !> Moves the allocated character scalar from 'from' to 'to'
     !> No output
-    subroutine move_string_char(from, to)
+    pure subroutine move_string_char(from, to)
         type(string_type), intent(inout) :: from
         character(len=:), intent(out), allocatable :: to
 
@@ -733,7 +733,7 @@ contains
 
     !> Moves the allocated character scalar from 'from' to 'to'
     !> No output
-    subroutine move_char_string(from, to)
+    pure subroutine move_char_string(from, to)
         character(len=:), intent(inout), allocatable :: from
         type(string_type), intent(out) :: to
 
@@ -743,7 +743,7 @@ contains
 
     !> Moves the allocated character scalar from 'from' to 'to'
     !> No output
-    subroutine move_char_char(from, to)
+    pure subroutine move_char_char(from, to)
         character(len=:), intent(inout), allocatable :: from
         character(len=:), intent(out), allocatable :: to
 

Diff for: src/stdlib_stringlist_type.f90

@@ -464,7 +464,7 @@ pure function shift( idx, shift_by )
         type(stringlist_index_type), intent(in)                 :: idx
         integer, intent(in)                                     :: shift_by
 
-        type(stringlist_index_type), intent(in)                 :: shift
+        type(stringlist_index_type)                             :: shift
 
         shift = merge( fidx( idx%offset + shift_by ), bidx( idx%offset + shift_by ), idx%forward )
 
@@ -607,7 +607,7 @@ end subroutine insert_at_stringarray_idx_wrap
     !> Modifies the input stringlist 'list'
     subroutine insert_before_engine( list, idxn, positions )
         !> Not a part of public API
-        class(stringlist_type), intent(inout)           :: list
+        type(stringlist_type), intent(inout)            :: list
         integer, intent(inout)                          :: idxn
         integer, intent(in)                             :: positions
 
@@ -740,8 +740,8 @@ end subroutine insert_before_stringarray_int_impl
     !> Returns strings present at stringlist_indexes in interval ['first', 'last']
     !> Stores requested strings in array 'capture_strings'
     !> No return
-    subroutine get_engine( list, first, last, capture_strings )
-        class(stringlist_type)                                  :: list
+    pure subroutine get_engine( list, first, last, capture_strings )
+        type(stringlist_type), intent(in)                       :: list
         type(stringlist_index_type), intent(in)                 :: first, last
         type(string_type), allocatable, intent(out)             :: capture_strings(:)
 
@@ -753,8 +753,7 @@ subroutine get_engine( list, first, last, capture_strings )
 
         ! out of bounds indexes won't be captured in capture_strings
         if ( from <= to ) then
-            pos = to - from + 1
-            allocate( capture_strings(pos) )
+            allocate( capture_strings( to - from + 1 ) )
 
             inew = 1
             do i = from, to
@@ -775,8 +774,8 @@ end subroutine get_engine
     pure function get_idx_impl( list, idx )
         class(stringlist_type), intent(in)                      :: list
         type(stringlist_index_type), intent(in)                 :: idx
-        type(string_type)                                       :: get_idx_impl
 
+        type(string_type)                                       :: get_idx_impl
         type(string_type), allocatable                          :: capture_strings(:)
 
         call get_engine( list, idx, idx, capture_strings )