errors in migrating code to different files

example/simple_get.f90

@@ -0,0 +1,11 @@
+program simple_get
+    use http_client, only : response_type, http_request, HTTP_GET
+    implicit none
+    type(response_type) :: response
+
+    response = http_request(url='https://jsonplaceholder.typicode.com/todos/1', method=HTTP_GET)
+    print *, "Response Code    : ", response%status_code
+    print *, "Response Length  : ", response%content_length
+    print *, "Response Content : ", response%content
+
+end program simple_get

fpm.toml

@@ -1,4 +1,4 @@
-name = "http-client"
+name = "http"
 version = "0.1.0"
 license = "MIT"
 author = "Fortran-lang"
@@ -18,3 +18,5 @@ implicit-typing = false
 implicit-external = false
 source-form = "free"
 
+[dependencies]
+fortran-curl = {git = "https://github.com/interkosmos/fortran-curl.git"}

src/http.f90

@@ -0,0 +1,56 @@
+module http
+    use http_request
+    use http_response, only : response_type
+    use http_client
+    implicit none
+
+    ! HTTP methods:
+    integer, parameter, public :: HTTP_GET    = 1
+    integer, parameter, public :: HTTP_HEAD   = 2
+    integer, parameter, public :: HTTP_POST   = 3
+    integer, parameter, public :: HTTP_PUT    = 4
+    integer, parameter, public :: HTTP_DELETE = 5
+    integer, parameter, public :: HTTP_PATCH  = 6
+
+    interface http_request
+        module procedure new_request
+    end interface http_request
+
+    ! Procedure defination
+    public :: http_request
+
+contains
+
+    ! Constructor for request_type type.
+    function new_request(url, method) result(response)
+        character(len=*) :: url
+        integer, optional :: method
+        type(request_type) :: request
+        type(response_type) :: response
+        type(client_type) :: client
+
+        if(present(method)) then 
+            if(method == 1) then
+                request%method = 'GET'  
+            else if (method == 2) then
+                request%method = 'HEAD'  
+            else if (method == 3) then
+                request%method = 'POST'  
+            else if (method == 4) then
+                request%method = 'PUT'  
+            else if(method == 5) then
+                request%method = 'DELETE' 
+            else if( method == 6) then
+                request%method = 'PATCH'  
+            end if      
+        else
+            request%method = 'GET'
+        end if
+        request%url = url
+        client = client_type(request=request)
+        response = client%client_get_response()
+
+    end function new_request
+
+
+end module http

src/http_client.f90

@@ -0,0 +1,94 @@
+module http_client
+    use, intrinsic :: iso_c_binding
+    use, intrinsic :: iso_fortran_env, only: i4 => int32, i8 => int64, r4 => real32, r8 => real64
+    use curl
+    use request_type
+    use response_type
+    implicit none
+
+    ! http_client Type
+    type :: client_type
+        type(request_type) :: request
+    contains
+        procedure :: client_get_response 
+    end type client_type
+
+    interface client_type
+        module procedure new_client
+    end interface client_type
+
+contains
+    ! Constructor for client_type type.
+    function new_client(request) result(client)
+        type(client_type) :: client
+        type(request_type) :: request
+
+        client%request = request
+    end function new_client
+
+    function client_get_response(this) result(response)
+        class(client_type) :: this
+        type(response_type), target :: response
+        type(c_ptr) :: curl_ptr
+        integer :: rc
+        ! logic for populating response using fortran-curl
+        response%url = this%request%url
+        response%method = this%request%method
+
+        curl_ptr = curl_easy_init()
+
+        if (.not. c_associated(curl_ptr)) then
+        stop 'Error: curl_easy_init() failed'
+        end if
+        ! setting request URL
+        rc = curl_easy_setopt(curl_ptr, CURLOPT_URL, this%request%url // c_null_char)
+        ! setting request method
+        rc = curl_easy_setopt(curl_ptr, CURLOPT_CUSTOMREQUEST, this%request%method // c_null_char)
+        ! setting callback for writing received data
+        rc = curl_easy_setopt(curl_ptr, CURLOPT_WRITEFUNCTION, c_funloc(client_response_callback))
+        ! setting response pointer to write callback
+        rc = curl_easy_setopt(curl_ptr, CURLOPT_WRITEDATA, c_loc(response))
+
+        ! Send request.
+        rc = curl_easy_perform(curl_ptr)
+
+        if (rc /= CURLE_OK) then
+        print '(a)', 'Error: curl_easy_perform() failed'
+        stop
+        end if
+        ! setting response status_code
+        rc = curl_easy_getinfo(curl_ptr, CURLINFO_RESPONSE_CODE, response%status_code)  
+        call curl_easy_cleanup(curl_ptr)
+
+    end function client_get_response
+
+    function client_response_callback(ptr, size, nmemb, client_data) bind(c)
+        type(c_ptr), intent(in), value :: ptr              
+        integer(kind=c_size_t), intent(in), value :: size           
+        integer(kind=c_size_t), intent(in), value :: nmemb         
+        type(c_ptr), intent(in), value :: client_data      
+        integer(kind=c_size_t) :: client_response_callback 
+        type(response_type), pointer :: response         
+        character(len=:), allocatable :: buf
+
+        client_response_callback = int(0, kind=c_size_t)
+
+        ! Are the passed C pointers associated?
+        if (.not. c_associated(ptr)) return
+        if (.not. c_associated(client_data)) return
+
+        ! Convert C pointer to Fortran pointer.
+        call c_f_pointer(client_data, response)
+        if (.not. allocated(response%content)) response%content = ''
+
+        ! Convert C pointer to Fortran allocatable character.
+        call c_f_str_ptr(ptr, buf, nmemb)
+        if (.not. allocated(buf)) return
+        response%content = response%content // buf
+        deallocate (buf)
+        response%content_length = response%content_length + nmemb
+        ! Return number of received bytes.
+        client_response_callback = nmemb
+    end function client_response_callback
+
+end module http_client

src/http_request.f90

@@ -0,0 +1,12 @@
+module http_request
+    use http_response, only : response_type
+    use http_client, only : client_type
+    implicit none
+
+    ! Request Type
+    type, public :: request_type
+        character(len=:), public, allocatable :: url
+        character(len=:), public, allocatable :: method
+    end type request_type
+
+end module http_request

src/http_response.f90

@@ -0,0 +1,14 @@
+module http_response
+    use, intrinsic :: iso_c_binding, only : c_size_t
+    implicit none
+
+    ! Response Type
+    type, public :: response_type
+        character(len=:), public, allocatable :: content
+        character(len=:), public, allocatable :: url
+        character(len=:), public, allocatable :: method
+        integer, public :: status_code
+        integer(kind=c_size_t), public:: content_length = 0 
+    end type response_type
+
+end module http_response