Merge pull request #64 from sourceryinstitute/string_t-concatenation

feat(string_t): support concatenation operator(//)

src/sourcery/sourcery_string_m.f90

@@ -14,6 +14,7 @@ module sourcery_string_m
     generic :: string => as_character
     procedure :: is_allocated
     procedure :: get_json_key
+    generic :: operator(//)   => string_t_cat_string_t, string_t_cat_character, character_cat_string_t
     generic :: operator(/=)   => string_t_ne_string_t, string_t_ne_character, character_ne_string_t
     generic :: operator(==)   => string_t_eq_string_t, string_t_eq_character, character_eq_string_t
     generic :: assignment(= ) => assign_string_t_to_character, assign_character_to_string_t
@@ -22,6 +23,8 @@ module sourcery_string_m
     procedure, private            :: string_t_ne_string_t, string_t_ne_character
     procedure, private            :: string_t_eq_string_t, string_t_eq_character
     procedure, private            :: assign_character_to_string_t
+    procedure, private            :: string_t_cat_string_t, string_t_cat_character
+    procedure, private, pass(rhs) :: character_cat_string_t
     procedure, private, pass(rhs) :: character_ne_string_t
     procedure, private, pass(rhs) :: character_eq_string_t
     procedure, private, pass(rhs) :: assign_string_t_to_character
@@ -137,6 +140,26 @@ elemental module function character_ne_string_t(lhs, rhs) result(lhs_ne_rhs)
       logical lhs_ne_rhs
     end function
 
+    pure module function string_t_cat_string_t(lhs, rhs) result(lhs_cat_rhs)
+      implicit none
+      class(string_t), intent(in) :: lhs, rhs
+      type(string_t) lhs_cat_rhs
+    end function
+
+    pure module function string_t_cat_character(lhs, rhs) result(lhs_cat_rhs)
+      implicit none
+      class(string_t), intent(in) :: lhs
+      character(len=*), intent(in) :: rhs
+      type(string_t) lhs_cat_rhs
+    end function
+
+    pure module function character_cat_string_t(lhs, rhs) result(lhs_cat_rhs)
+      implicit none
+      character(len=*), intent(in) :: lhs
+      class(string_t), intent(in) :: rhs
+      type(string_t) lhs_cat_rhs
+    end function
+
     pure module subroutine assign_character_to_string_t(lhs, rhs)
       implicit none
       class(string_t), intent(inout) :: lhs

src/sourcery/sourcery_string_s.f90

@@ -186,5 +186,17 @@
   module procedure assign_character_to_string_t
     lhs%string_ = rhs
   end procedure
+
+  module procedure string_t_cat_string_t
+    lhs_cat_rhs = string_t(lhs%string_ // rhs%string_)
+  end procedure
+
+  module procedure string_t_cat_character
+    lhs_cat_rhs = string_t(lhs%string_ // rhs)
+  end procedure
+
+  module procedure character_cat_string_t
+    lhs_cat_rhs = string_t(lhs // rhs%string_)
+  end procedure
 
 end submodule sourcery_string_s

test/string_test.f90

@@ -33,7 +33,8 @@ function results() result(test_results)
       test_result_t('supporting operator(==) for string_t and character operands', supports_equivalence_operator()), &
       test_result_t('supporting operator(/=) for string_t and character operands', supports_non_equivalence_operator()), &
       test_result_t('assigning a string_t object to a character variable', assigns_string_t_to_character()), &
-      test_result_t('assigning a character variable to a string_t object', assigns_character_to_string_t()) &
+      test_result_t('assigning a character variable to a string_t object', assigns_character_to_string_t()), &
+      test_result_t('supporting operator(//) for string_t and character operands', supports_concatenation_operator()) &
     ]
   end function
 
@@ -141,4 +142,13 @@ function assigns_character_to_string_t() result(passed)
     passed = lhs == rhs
   end function
 
+  function supports_concatenation_operator() result(passed)
+    logical passed
+    character(len=*), parameter :: prefix = "foo", postfix="bar"
+
+    associate(infix => string_t(" yada yada "))
+      passed = prefix // infix // postfix == prefix // infix%string() // postfix 
+    end associate
+  end function
+
 end module string_test_m