From b7f94b3ddf0dc1c226b5fa12008b316e7f1b8480 Mon Sep 17 00:00:00 2001
From: "Vandenplas, Jeremie" <jeremie.vandenplas@gmail.com>
Date: Mon, 6 Jan 2020 16:22:20 +0100
Subject: [PATCH 1/2] addition of access in the API of open function + tests

---
 src/stdlib_experimental_io.f90 | 22 ++++++++++---
 src/tests/io/Makefile.manual   |  4 ++-
 src/tests/io/test_open.f90     | 60 +++++++++++++++++++++++++++++++---
 3 files changed, 76 insertions(+), 10 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 05f0a256f..adfef7a2d 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -269,7 +269,7 @@ integer function number_of_rows_numeric(s)
 
 end function
 
-integer function open(filename, mode, iostat) result(u)
+integer function open(filename, mode, iostat, access) result(u)
 ! Open a file
 !
 ! To open a file to read:
@@ -287,6 +287,7 @@ integer function open(filename, mode, iostat) result(u)
 
 character(*), intent(in) :: filename
 character(*), intent(in), optional :: mode
+character(*), intent(in), optional :: access
 integer, intent(out), optional :: iostat
 
 integer :: io_
@@ -335,15 +336,28 @@ integer function open(filename, mode, iostat) result(u)
 
 select case (mode_(3:3))
 case('t')
-    access_='sequential'
     form_='formatted'
-case('b', 's')
-    access_='stream'
+case('b')
     form_='unformatted'
 case default
     call error_stop("Unsupported mode: "//mode_(3:3))
 end select
 
+access_='stream'
+
+if (present(access)) then
+    select case (trim(adjustl(access)))
+    case('direct')
+        access_='direct'
+    case('sequential')
+        access_='sequential'
+    case('stream')
+        access_='stream'
+    case default
+        call error_stop("Unsupported access: "//trim(access))
+    end select
+end if
+
 if (present(iostat)) then
     open(newunit=u, file=filename, &
          action = action_, position = position_, status = status_, &
diff --git a/src/tests/io/Makefile.manual b/src/tests/io/Makefile.manual
index 3bbce9db7..f5ae133e9 100644
--- a/src/tests/io/Makefile.manual
+++ b/src/tests/io/Makefile.manual
@@ -5,7 +5,9 @@ PROGS_SRC = test_loadtxt.f90 \
 			test_parse_mode.f90 \
 			test_open.f90
 
-CLEAN_FILES = tmp.dat tmp_qp.dat io_open.dat io_open.stream
+CLEAN_FILES = tmp.dat tmp_qp.dat \
+		io_open_seq.dat io_open_stream.dat \
+		io_open_seq.bin io_open_stream.bin
 
 
 include ../Makefile.manual.test.mk
diff --git a/src/tests/io/test_open.f90 b/src/tests/io/test_open.f90
index deaee3593..22f8f61cf 100644
--- a/src/tests/io/test_open.f90
+++ b/src/tests/io/test_open.f90
@@ -6,8 +6,8 @@ program test_open
 character(:), allocatable :: filename
 integer :: io, u, a(3)
 
-! Text file
-filename = get_outpath() // "/io_open.dat"
+! Stream text file
+filename = get_outpath() // "/io_open_stream.dat"
 
 ! Test mode "w"
 u = open(filename, "w")
@@ -32,9 +32,34 @@ program test_open
 close(u)
 
 
+! Sequential text file
+filename = get_outpath() // "/io_open_seq.dat"
 
-! Stream file
-filename = get_outpath() // "/io_open.stream"
+! Test mode "w"
+u = open(filename, "w", access = 'sequential')
+write(u, *) 1, 2, 3
+close(u)
+
+! Test mode "r"
+u = open(filename, "r", access = 'sequential')
+read(u, *) a
+call assert(all(a == [1, 2, 3]))
+close(u)
+
+! Test mode "a"
+u = open(filename, "a", access = 'sequential')
+write(u, *) 4, 5, 6
+close(u)
+u = open(filename, "r", access = 'sequential')
+read(u, *) a
+call assert(all(a == [1, 2, 3]))
+read(u, *) a
+call assert(all(a == [4, 5, 6]))
+close(u)
+
+
+! Stream binary file
+filename = get_outpath() // "/io_open_stream.bin"
 
 ! Test mode "w"
 u = open(filename, "wb")
@@ -59,9 +84,34 @@ program test_open
 close(u)
 
 
+! Sequential binary file
+filename = get_outpath() // "/io_open_seq.bin"
+
+! Test mode "w"
+u = open(filename, "wb", access = 'sequential')
+write(u) 1, 2, 3
+close(u)
+
+! Test mode "r"
+u = open(filename, "rb", access = 'sequential')
+read(u) a
+call assert(all(a == [1, 2, 3]))
+close(u)
+
+! Test mode "a"
+u = open(filename, "ab", access = 'sequential')
+write(u) 4, 5, 6
+close(u)
+u = open(filename, "rb", access = 'sequential')
+read(u) a
+call assert(all(a == [1, 2, 3]))
+read(u) a
+call assert(all(a == [4, 5, 6]))
+close(u)
+
 
 !0 and non-0 open
-filename = get_outpath() // "/io_open.stream"
+filename = get_outpath() // "/io_open_stream.bin"
 
 u = open(filename, "rb", io)
 call assert(io == 0)

From 58facbd0b2846d6471077a04baf892becbf8d4de Mon Sep 17 00:00:00 2001
From: "Vandenplas, Jeremie" <jeremie.vandenplas@gmail.com>
Date: Mon, 6 Jan 2020 22:21:22 +0100
Subject: [PATCH 2/2] Commented direct access because not well supported

---
 src/stdlib_experimental_io.f90 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 932cdfe8f..2b20d6234 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -347,8 +347,8 @@ integer function open(filename, mode, iostat, access) result(u)
 
 if (present(access)) then
     select case (trim(adjustl(access)))
-    case('direct')
-        access_ = 'direct'
+!    case('direct')
+!        access_ = 'direct'
     case('sequential')
         access_ = 'sequential'
     case('stream')