From ac61bf40224516a1d7ca846a7b9aa227d6c5093d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Thu, 2 Jan 2020 20:33:45 -0700
Subject: [PATCH 01/14] Implement open(filename, mode) and use it

---
 src/stdlib_experimental_io.f90 | 43 ++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index ed93c63e1..3623b8c01 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -1,8 +1,9 @@
 module stdlib_experimental_io
 use iso_fortran_env, only: sp=>real32, dp=>real64, qp=>real128
+use stdlib_experimental_error, only: error_stop
 implicit none
 private
-public :: loadtxt, savetxt
+public :: loadtxt, savetxt, open
 
 interface loadtxt
     module procedure sloadtxt
@@ -46,7 +47,7 @@ subroutine sloadtxt(filename, d)
 integer :: s
 integer :: nrow,ncol,i
 
-open(newunit=s, file=filename, status="old", action="read")
+s = open(filename)
 
 ! determine number of columns
 ncol = number_of_columns(s)
@@ -89,7 +90,7 @@ subroutine dloadtxt(filename, d)
 integer :: s
 integer :: nrow,ncol,i
 
-open(newunit=s, file=filename, status="old", action="read")
+s = open(filename)
 
 ! determine number of columns
 ncol = number_of_columns(s)
@@ -132,7 +133,7 @@ subroutine qloadtxt(filename, d)
 integer :: s
 integer :: nrow,ncol,i
 
-open(newunit=s, file=filename, status="old", action="read")
+s = open(filename)
 
 ! determine number of columns
 ncol = number_of_columns(s)
@@ -164,7 +165,7 @@ subroutine ssavetxt(filename, d)
 ! call savetxt("log.txt", data)
 
 integer :: s, i
-open(newunit=s, file=filename, status="replace", action="write")
+s = open(filename, "w")
 do i = 1, size(d, 1)
     write(s, *) d(i, :)
 end do
@@ -187,7 +188,7 @@ subroutine dsavetxt(filename, d)
 ! call savetxt("log.txt", data)
 
 integer :: s, i
-open(newunit=s, file=filename, status="replace", action="write")
+s = open(filename, "w")
 do i = 1, size(d, 1)
     write(s, *) d(i, :)
 end do
@@ -210,7 +211,7 @@ subroutine qsavetxt(filename, d)
 ! call savetxt("log.txt", data)
 
 integer :: s, i
-open(newunit=s, file=filename, status="replace", action="write")
+s = open(filename, "w")
 do i = 1, size(d, 1)
     write(s, *) d(i, :)
 end do
@@ -268,4 +269,32 @@ logical function whitechar(char) ! white character
 end if
 end function
 
+integer function open(filename, mode) result(u)
+! Open a file
+!
+! To open a file to read:
+!
+! u = open("somefile.txt")        # The default `mode` is "r"
+! u = open("somefile.txt", "r")
+!
+! To open a file to write:
+!
+! u = open("somefile.txt", "w")
+
+character(*), intent(in) :: filename
+character(*), intent(in), optional :: mode
+character(:), allocatable :: mode_
+mode_ = "r"
+if (present(mode)) mode_ = mode
+! Note: the Fortran standard says that the default values for `status` and
+! `action` are processor dependent, so we have to explicitly set them below
+if (mode_ == "r") then
+    open(newunit=u, file=filename, status="old", action="read")
+else if (mode_ == "w") then
+    open(newunit=u, file=filename, status="replace", action="write")
+else
+    call error_stop("Unsupported mode")
+end if
+end function
+
 end module

From c8a3fcaa7d78e7e3cfefa5c2a024246d1a824875 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Thu, 2 Jan 2020 21:26:37 -0700
Subject: [PATCH 02/14] Implement mode="a"

---
 src/stdlib_experimental_io.f90 | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 3623b8c01..778dc5d67 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -281,6 +281,10 @@ integer function open(filename, mode) result(u)
 !
 ! u = open("somefile.txt", "w")
 
+! To append to the end of the file if it exists:
+!
+! u = open("somefile.txt", "a")
+
 character(*), intent(in) :: filename
 character(*), intent(in), optional :: mode
 character(:), allocatable :: mode_
@@ -292,6 +296,9 @@ integer function open(filename, mode) result(u)
     open(newunit=u, file=filename, status="old", action="read")
 else if (mode_ == "w") then
     open(newunit=u, file=filename, status="replace", action="write")
+else if (mode_ == "a") then
+    open(newunit=u, file=filename, position="append", status="old", &
+        action="write")
 else
     call error_stop("Unsupported mode")
 end if

From d2d3bfa9cb81018a32e1205e7f1bcc7bef83e095 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Fri, 3 Jan 2020 09:04:39 -0700
Subject: [PATCH 03/14] Rename loadtxt test directory to io

---
 src/tests/CMakeLists.txt                      | 2 +-
 src/tests/Makefile.manual                     | 8 ++++----
 src/tests/{loadtxt => io}/CMakeLists.txt      | 0
 src/tests/{loadtxt => io}/Makefile.manual     | 0
 src/tests/{loadtxt => io}/array1.dat          | 0
 src/tests/{loadtxt => io}/array2.dat          | 0
 src/tests/{loadtxt => io}/array3.dat          | 0
 src/tests/{loadtxt => io}/array4.dat          | 0
 src/tests/{loadtxt => io}/test_loadtxt.f90    | 0
 src/tests/{loadtxt => io}/test_loadtxt_qp.f90 | 0
 src/tests/{loadtxt => io}/test_savetxt.f90    | 0
 src/tests/{loadtxt => io}/test_savetxt_qp.f90 | 0
 12 files changed, 5 insertions(+), 5 deletions(-)
 rename src/tests/{loadtxt => io}/CMakeLists.txt (100%)
 rename src/tests/{loadtxt => io}/Makefile.manual (100%)
 rename src/tests/{loadtxt => io}/array1.dat (100%)
 rename src/tests/{loadtxt => io}/array2.dat (100%)
 rename src/tests/{loadtxt => io}/array3.dat (100%)
 rename src/tests/{loadtxt => io}/array4.dat (100%)
 rename src/tests/{loadtxt => io}/test_loadtxt.f90 (100%)
 rename src/tests/{loadtxt => io}/test_loadtxt_qp.f90 (100%)
 rename src/tests/{loadtxt => io}/test_savetxt.f90 (100%)
 rename src/tests/{loadtxt => io}/test_savetxt_qp.f90 (100%)

diff --git a/src/tests/CMakeLists.txt b/src/tests/CMakeLists.txt
index 7ba8c4a4f..a8ac32b8e 100644
--- a/src/tests/CMakeLists.txt
+++ b/src/tests/CMakeLists.txt
@@ -1,3 +1,3 @@
 add_subdirectory(ascii)
-add_subdirectory(loadtxt)
+add_subdirectory(io)
 
diff --git a/src/tests/Makefile.manual b/src/tests/Makefile.manual
index 2669a98f8..73d0db113 100644
--- a/src/tests/Makefile.manual
+++ b/src/tests/Makefile.manual
@@ -1,13 +1,13 @@
 .PHONY: all clean
 
-all: ascii/test_ascii loadtxt/test_loadtxt
+all: ascii/test_ascii io/test_loadtxt
 
 ascii/test_ascii:
 	$(MAKE) -f Makefile.manual --directory=ascii
 
-loadtxt/test_loadtxt:
-	$(MAKE) -f Makefile.manual --directory=loadtxt
+io/test_loadtxt:
+	$(MAKE) -f Makefile.manual --directory=io
 
 clean:
 	$(MAKE) -f Makefile.manual --directory=ascii clean
-	$(MAKE) -f Makefile.manual --directory=loadtxt clean
+	$(MAKE) -f Makefile.manual --directory=io clean
diff --git a/src/tests/loadtxt/CMakeLists.txt b/src/tests/io/CMakeLists.txt
similarity index 100%
rename from src/tests/loadtxt/CMakeLists.txt
rename to src/tests/io/CMakeLists.txt
diff --git a/src/tests/loadtxt/Makefile.manual b/src/tests/io/Makefile.manual
similarity index 100%
rename from src/tests/loadtxt/Makefile.manual
rename to src/tests/io/Makefile.manual
diff --git a/src/tests/loadtxt/array1.dat b/src/tests/io/array1.dat
similarity index 100%
rename from src/tests/loadtxt/array1.dat
rename to src/tests/io/array1.dat
diff --git a/src/tests/loadtxt/array2.dat b/src/tests/io/array2.dat
similarity index 100%
rename from src/tests/loadtxt/array2.dat
rename to src/tests/io/array2.dat
diff --git a/src/tests/loadtxt/array3.dat b/src/tests/io/array3.dat
similarity index 100%
rename from src/tests/loadtxt/array3.dat
rename to src/tests/io/array3.dat
diff --git a/src/tests/loadtxt/array4.dat b/src/tests/io/array4.dat
similarity index 100%
rename from src/tests/loadtxt/array4.dat
rename to src/tests/io/array4.dat
diff --git a/src/tests/loadtxt/test_loadtxt.f90 b/src/tests/io/test_loadtxt.f90
similarity index 100%
rename from src/tests/loadtxt/test_loadtxt.f90
rename to src/tests/io/test_loadtxt.f90
diff --git a/src/tests/loadtxt/test_loadtxt_qp.f90 b/src/tests/io/test_loadtxt_qp.f90
similarity index 100%
rename from src/tests/loadtxt/test_loadtxt_qp.f90
rename to src/tests/io/test_loadtxt_qp.f90
diff --git a/src/tests/loadtxt/test_savetxt.f90 b/src/tests/io/test_savetxt.f90
similarity index 100%
rename from src/tests/loadtxt/test_savetxt.f90
rename to src/tests/io/test_savetxt.f90
diff --git a/src/tests/loadtxt/test_savetxt_qp.f90 b/src/tests/io/test_savetxt_qp.f90
similarity index 100%
rename from src/tests/loadtxt/test_savetxt_qp.f90
rename to src/tests/io/test_savetxt_qp.f90

From 6a263ffa40ae122c9e074de170eecbf47775d74b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Fri, 3 Jan 2020 09:05:02 -0700
Subject: [PATCH 04/14] Add a test for "open"

---
 src/tests/io/CMakeLists.txt |  5 ++++
 src/tests/io/test_open.f90  | 49 +++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)
 create mode 100644 src/tests/io/test_open.f90

diff --git a/src/tests/io/CMakeLists.txt b/src/tests/io/CMakeLists.txt
index 5cef2a4f8..fb3d7179e 100644
--- a/src/tests/io/CMakeLists.txt
+++ b/src/tests/io/CMakeLists.txt
@@ -10,6 +10,9 @@ target_link_libraries(test_loadtxt_qp fortran_stdlib)
 add_executable(test_savetxt_qp test_savetxt_qp.f90)
 target_link_libraries(test_savetxt_qp fortran_stdlib)
 
+add_executable(test_open test_open.f90)
+target_link_libraries(test_open fortran_stdlib)
+
 add_test(NAME loadtxt COMMAND $<TARGET_FILE:test_loadtxt> ${CMAKE_CURRENT_BINARY_DIR}
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 add_test(NAME savetxt COMMAND $<TARGET_FILE:test_savetxt> ${CMAKE_CURRENT_BINARY_DIR}
@@ -18,6 +21,8 @@ add_test(NAME loadtxt_qp COMMAND $<TARGET_FILE:test_loadtxt_qp> ${CMAKE_CURRENT_
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 add_test(NAME savetxt_qp COMMAND $<TARGET_FILE:test_savetxt_qp> ${CMAKE_CURRENT_BINARY_DIR}
   WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+add_test(NAME open COMMAND $<TARGET_FILE:test_open> ${CMAKE_CURRENT_BINARY_DIR}
+  WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
 
 set_tests_properties(loadtxt_qp PROPERTIES LABELS quadruple_precision)
 set_tests_properties(savetxt_qp PROPERTIES LABELS quadruple_precision)
diff --git a/src/tests/io/test_open.f90 b/src/tests/io/test_open.f90
new file mode 100644
index 000000000..eb66af519
--- /dev/null
+++ b/src/tests/io/test_open.f90
@@ -0,0 +1,49 @@
+program test_open
+use stdlib_experimental_io, only: open
+use stdlib_experimental_error, only: assert
+implicit none
+
+character(:), allocatable :: filename
+integer :: u, a(3)
+
+filename = get_outpath() // "/io_open.dat"
+
+! Test mode "w"
+u = open(filename, "w")
+write(u, *) 1, 2, 3
+close(u)
+
+! Test mode "r"
+u = open(filename, "r")
+read(u, *) a
+call assert(all(a == [1, 2, 3]))
+close(u)
+
+! Test mode "a"
+u = open(filename, "a")
+write(u, *) 4, 5, 6
+close(u)
+u = open(filename, "r")
+read(u, *) a
+call assert(all(a == [1, 2, 3]))
+read(u, *) a
+call assert(all(a == [4, 5, 6]))
+close(u)
+
+
+contains
+
+    function get_outpath() result(outpath)
+    integer :: ierr
+    character(256) :: argv
+    character(:), allocatable :: outpath
+
+    call get_command_argument(1, argv, status=ierr)
+    if (ierr==0) then
+        outpath = trim(argv)
+    else
+        outpath = '.'
+    endif
+    end function get_outpath
+
+end program

From ab5c469d7c253e494e40818a3dd8afd9319b1905 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Fri, 3 Jan 2020 09:11:35 -0700
Subject: [PATCH 05/14] Apply suggestions from code review

Co-Authored-By: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>
---
 src/stdlib_experimental_io.f90 | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 778dc5d67..b3fa9c3a4 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -274,7 +274,7 @@ integer function open(filename, mode) result(u)
 !
 ! To open a file to read:
 !
-! u = open("somefile.txt")        # The default `mode` is "r"
+! u = open("somefile.txt")        # The default `mode` is "rt"
 ! u = open("somefile.txt", "r")
 !
 ! To open a file to write:
@@ -288,17 +288,22 @@ integer function open(filename, mode) result(u)
 character(*), intent(in) :: filename
 character(*), intent(in), optional :: mode
 character(:), allocatable :: mode_
-mode_ = "r"
+mode_ = "rt"
 if (present(mode)) mode_ = mode
 ! Note: the Fortran standard says that the default values for `status` and
 ! `action` are processor dependent, so we have to explicitly set them below
-if (mode_ == "r") then
-    open(newunit=u, file=filename, status="old", action="read")
-else if (mode_ == "w") then
-    open(newunit=u, file=filename, status="replace", action="write")
-else if (mode_ == "a") then
+if (mode_ == "r" .or. mode_ == 'rt') then
+    open(newunit=u, file=filename, status="old", action="read", &
+             access='sequential', form='formatted')
+else if (mode_ == "w" .or. mode_ == "wt") then
+    open(newunit=u, file=filename, status="replace", action="write", &
+              access='sequential', form='formatted')
+else if (mode_ == "a" .or. mode_ == "at") then
     open(newunit=u, file=filename, position="append", status="old", &
-        action="write")
+        action="write", access='sequential', form='formatted')
+else if (mode_ == "x" .or. mode_ == "xt") then
+    open(newunit=u, file=filename, status="new", &
+            action="write", access='sequential', form='formatted')
 else
     call error_stop("Unsupported mode")
 end if

From 13a668ead5e9d0a1b22da9659b8b6d1a6f04a15c Mon Sep 17 00:00:00 2001
From: "Vandenplas, Jeremie" <jeremie.vandenplas@gmail.com>
Date: Sat, 4 Jan 2020 11:14:12 +0100
Subject: [PATCH 06/14] stdlib_experimental_io: addition of a parser and
 characters "+" and "s"/"b" for stream access

---
 src/stdlib_experimental_io.f90 | 95 +++++++++++++++++++++++++++-------
 1 file changed, 77 insertions(+), 18 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index b3fa9c3a4..79188d65c 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -287,26 +287,85 @@ integer function open(filename, mode) result(u)
 
 character(*), intent(in) :: filename
 character(*), intent(in), optional :: mode
-character(:), allocatable :: mode_
-mode_ = "rt"
-if (present(mode)) mode_ = mode
-! Note: the Fortran standard says that the default values for `status` and
-! `action` are processor dependent, so we have to explicitly set them below
-if (mode_ == "r" .or. mode_ == 'rt') then
-    open(newunit=u, file=filename, status="old", action="read", &
-             access='sequential', form='formatted')
-else if (mode_ == "w" .or. mode_ == "wt") then
-    open(newunit=u, file=filename, status="replace", action="write", &
-              access='sequential', form='formatted')
-else if (mode_ == "a" .or. mode_ == "at") then
-    open(newunit=u, file=filename, position="append", status="old", &
-        action="write", access='sequential', form='formatted')
-else if (mode_ == "x" .or. mode_ == "xt") then
-    open(newunit=u, file=filename, status="new", &
-            action="write", access='sequential', form='formatted')
+integer :: io
+character(3):: mode_
+character(:),allocatable :: action_, position_, status_, access_, form_
+
+
+mode_ = "r t"
+if (present(mode)) mode_ = parse_mode(mode)
+
+if (mode_(1:2) == 'r ') then
+    action_='read'
+    position_='asis'
+    status_='old'
+else if (mode_(1:2) == 'w ') then
+    action_='write'
+    position_='asis'
+    status_='replace'
+else if (mode_(1:2) == 'a ') then
+    action_='write'
+    position_='append'
+    status_='old'
+else if (mode_(1:2) == 'x ') then
+    action_='write'
+    position_='asis'
+    status_='new'
+else if (mode_(1:2) == 'r+') then
+    action_='readwrite'
+    position_='asis'
+    status_='old'
+else if (mode_(1:2) == 'w+') then
+    action_='readwrite'
+    position_='asis'
+    status_='replace'
+else if (mode_(1:2) == 'a+') then
+    action_='readwrite'
+    position_='append'
+    status_='old'
+else if (mode_(1:2) == 'x+') then
+    action_='readwrite'
+    position_='asis'
+    status_='new'
 else
-    call error_stop("Unsupported mode")
+    call error_stop("Unsupported mode: "//mode_(1:2))
 end if
+
+if (mode_(3:3) == 't') then
+    access_='sequential'
+    form_='formatted'
+else if (mode_(3:3) == 'b' .or. mode_(3:3) == 's') then
+    access_='stream'
+    form_='unformatted'
+else
+    call error_stop("Unsupported mode: "//mode_(3:3))
+endif
+
+open(newunit=u, file=filename, &
+     action = action_, position = position_, status = status_, &
+     access = access_, form = form_, &
+     iostat = io)
+
+end function
+
+character(3) function parse_mode(mode) result(mode_)
+character(*), intent(in) :: mode
+
+mode_ = 'r t'
+mode_(1:1) = mode(1:1)
+
+if (len_trim(adjustl(mode)) > 1) then
+    if (mode(2:2) == '+' )then
+        mode_(2:2) = '+'
+    else
+        mode_(3:3) = mode(2:2)
+    endif
+end if
+
+if (len_trim(adjustl(mode)) > 2) then
+        mode_(3:3) = mode(3:3)
+end if
+
 end function
 
 end module

From 2f1a0e813dcdaec0e881663d5ce9942b61a260a3 Mon Sep 17 00:00:00 2001
From: "Vandenplas, Jeremie" <jeremie.vandenplas@gmail.com>
Date: Sat, 4 Jan 2020 15:01:40 +0100
Subject: [PATCH 07/14] test_open: addition of a test for stream files

---
 src/tests/io/Makefile.manual |  7 +++++--
 src/tests/io/test_open.f90   | 27 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/src/tests/io/Makefile.manual b/src/tests/io/Makefile.manual
index 716f41678..b3df0f5d8 100644
--- a/src/tests/io/Makefile.manual
+++ b/src/tests/io/Makefile.manual
@@ -5,7 +5,7 @@ OBJS = ../../stdlib_experimental_error.o \
 .PHONY: all clean
 .SUFFIXES: .f90 .o
 
-all: test_loadtxt test_savetxt
+all: test_loadtxt test_savetxt test_open
 
 test_loadtxt: test_loadtxt.f90 $(OBJS)
 	$(FC) $(FCFLAGS) $(CPPFLAGS) $< -o $@ $(OBJS)
@@ -13,8 +13,11 @@ test_loadtxt: test_loadtxt.f90 $(OBJS)
 test_savetxt: test_savetxt.f90 $(OBJS)
 	$(FC) $(FCFLAGS) $(CPPFLAGS) $< -o $@ $(OBJS)
 
+test_open: test_open.f90 $(OBJS)
+	$(FC) $(FCFLAGS) $(CPPFLAGS) $< -o $@ $(OBJS)
+
 %.o: %.mod
 
 clean:
-	$(RM) test_loadtxt test_savetxt
+	$(RM) test_loadtxt test_savetxt test_open
 	$(RM) *.o *.mod
diff --git a/src/tests/io/test_open.f90 b/src/tests/io/test_open.f90
index eb66af519..2169d0861 100644
--- a/src/tests/io/test_open.f90
+++ b/src/tests/io/test_open.f90
@@ -6,6 +6,7 @@ program test_open
 character(:), allocatable :: filename
 integer :: u, a(3)
 
+! Text file
 filename = get_outpath() // "/io_open.dat"
 
 ! Test mode "w"
@@ -31,6 +32,32 @@ program test_open
 close(u)
 
 
+
+! Stream file
+filename = get_outpath() // "/io_open.stream"
+
+! Test mode "w"
+u = open(filename, "wb")
+write(u) 1, 2, 3
+close(u)
+
+! Test mode "r"
+u = open(filename, "rb")
+read(u) a
+call assert(all(a == [1, 2, 3]))
+close(u)
+
+! Test mode "a"
+u = open(filename, "ab")
+write(u) 4, 5, 6
+close(u)
+u = open(filename, "rb")
+read(u) a
+call assert(all(a == [1, 2, 3]))
+read(u) a
+call assert(all(a == [4, 5, 6]))
+close(u)
+
 contains
 
     function get_outpath() result(outpath)

From 041a4e13607972fd720fc3d3e7d944f09856c8b2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 13:37:03 -0700
Subject: [PATCH 08/14] Clean test files

---
 src/tests/io/Makefile.manual | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/tests/io/Makefile.manual b/src/tests/io/Makefile.manual
index d83b5c91a..0e18c6aca 100644
--- a/src/tests/io/Makefile.manual
+++ b/src/tests/io/Makefile.manual
@@ -4,7 +4,7 @@ PROGS_SRC = test_loadtxt.f90 \
 			test_savetxt_qp.f90 \
 			test_open.f90
 
-CLEAN_FILES = tmp.dat tmp_qp.dat
+CLEAN_FILES = tmp.dat tmp_qp.dat io_open.dat io_open.stream
 
 
 include ../Makefile.manual.test.mk

From b0b3dbfe6d62b8888e9afa214c8ea6a2db030a36 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 13:55:52 -0700
Subject: [PATCH 09/14] Add tests for parse_mode()

---
 src/stdlib_experimental_io.f90 |  5 ++++
 src/tests/io/test_open.f90     | 45 +++++++++++++++++++++++++++++++++-
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 79188d65c..d034d6fbc 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -3,8 +3,13 @@ module stdlib_experimental_io
 use stdlib_experimental_error, only: error_stop
 implicit none
 private
+! Public API
 public :: loadtxt, savetxt, open
 
+! Private API that is exposed so that we can test it in tests
+public :: parse_mode
+
+
 interface loadtxt
     module procedure sloadtxt
     module procedure dloadtxt
diff --git a/src/tests/io/test_open.f90 b/src/tests/io/test_open.f90
index 2169d0861..c85192c14 100644
--- a/src/tests/io/test_open.f90
+++ b/src/tests/io/test_open.f90
@@ -1,11 +1,13 @@
 program test_open
-use stdlib_experimental_io, only: open
+use stdlib_experimental_io, only: open, parse_mode
 use stdlib_experimental_error, only: assert
 implicit none
 
 character(:), allocatable :: filename
 integer :: u, a(3)
 
+call test_parse_mode()
+
 ! Text file
 filename = get_outpath() // "/io_open.dat"
 
@@ -73,4 +75,45 @@ function get_outpath() result(outpath)
     endif
     end function get_outpath
 
+    subroutine test_parse_mode()
+    character(3) :: m
+    m = parse_mode("")
+    call assert(m == "r t")
+
+    m = parse_mode("r")
+    call assert(m == "r t")
+    m = parse_mode("w")
+    call assert(m == "w t")
+    m = parse_mode("a")
+    call assert(m == "a t")
+
+    m = parse_mode("rb")
+    call assert(m == "r b")
+    m = parse_mode("wb")
+    call assert(m == "w b")
+    m = parse_mode("ab")
+    call assert(m == "a b")
+
+    m = parse_mode("br")
+    !call assert(m == "r b")
+    m = parse_mode("bw")
+    !call assert(m == "w b")
+    m = parse_mode("ba")
+    !call assert(m == "a b")
+
+    m = parse_mode("r+")
+    call assert(m == "r+t")
+    m = parse_mode("w+")
+    call assert(m == "w+t")
+    m = parse_mode("a+")
+    call assert(m == "a+t")
+
+    m = parse_mode("r+b")
+    call assert(m == "r+b")
+    m = parse_mode("w+b")
+    call assert(m == "w+b")
+    m = parse_mode("a+b")
+    call assert(m == "a+b")
+    end subroutine
+
 end program

From 08dc86b8c514276ca4564d7359df5e69329c580e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 14:00:07 -0700
Subject: [PATCH 10/14] Allow any order of characters in the mode

---
 src/stdlib_experimental_io.f90 | 5 +++++
 src/tests/io/test_open.f90     | 6 +++---
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index d034d6fbc..c03b31e39 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -371,6 +371,11 @@ integer function open(filename, mode) result(u)
         mode_(3:3) = mode(3:3)
 end if
 
+if (mode_(1:1) == 'b') then
+    mode_(1:1) = mode_(3:3)
+    mode_(3:3) = 'b'
+end if
+
 end function
 
 end module
diff --git a/src/tests/io/test_open.f90 b/src/tests/io/test_open.f90
index c85192c14..471c43952 100644
--- a/src/tests/io/test_open.f90
+++ b/src/tests/io/test_open.f90
@@ -95,11 +95,11 @@ subroutine test_parse_mode()
     call assert(m == "a b")
 
     m = parse_mode("br")
-    !call assert(m == "r b")
+    call assert(m == "r b")
     m = parse_mode("bw")
-    !call assert(m == "w b")
+    call assert(m == "w b")
     m = parse_mode("ba")
-    !call assert(m == "a b")
+    call assert(m == "a b")
 
     m = parse_mode("r+")
     call assert(m == "r+t")

From 5128458615fa8e5dca2156da657c28fa5909a538 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 14:04:24 -0700
Subject: [PATCH 11/14] Fix an out of bounds error

---
 src/stdlib_experimental_io.f90 | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index c03b31e39..4e34fbc83 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -357,6 +357,7 @@ integer function open(filename, mode) result(u)
 character(*), intent(in) :: mode
 
 mode_ = 'r t'
+if (len_trim(mode) == 0) return
 mode_(1:1) = mode(1:1)
 
 if (len_trim(adjustl(mode)) > 1) then

From 48cbf24fff34577cd465332d91dcc006fbab0053 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 14:07:51 -0700
Subject: [PATCH 12/14] Let parse_mode() set the default value

---
 src/stdlib_experimental_io.f90 | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 4e34fbc83..07c060300 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -297,8 +297,11 @@ integer function open(filename, mode) result(u)
 character(:),allocatable :: action_, position_, status_, access_, form_
 
 
-mode_ = "r t"
-if (present(mode)) mode_ = parse_mode(mode)
+! Note: with `optval` this could be written as:
+! mode_ = parse_mode(optval(mode, ""))
+mode_ = ""
+if (present(mode)) mode_ = mode
+mode_ = parse_mode(mode_)
 
 if (mode_(1:2) == 'r ') then
     action_='read'

From a98832cc23542e8714015a5e87262671c9a69f8e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 14:11:20 -0700
Subject: [PATCH 13/14] Manual Makefiles: add a new dependency

---
 src/Makefile.manual | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Makefile.manual b/src/Makefile.manual
index 71b6a8a31..a58dfb852 100644
--- a/src/Makefile.manual
+++ b/src/Makefile.manual
@@ -27,3 +27,4 @@ clean:
 
 # Fortran module dependencies
 f18estop.o: stdlib_experimental_error.o
+stdlib_experimental_io.o: stdlib_experimental_error.o

From a8416a10a1b2db974dfa6192fe486c8d16b24e8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20=C4=8Cert=C3=ADk?= <ondrej@certik.us>
Date: Sat, 4 Jan 2020 14:23:37 -0700
Subject: [PATCH 14/14] Use optval

---
 src/Makefile.manual            | 2 +-
 src/stdlib_experimental_io.f90 | 7 ++-----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/src/Makefile.manual b/src/Makefile.manual
index c2af5de63..31ca7cad7 100644
--- a/src/Makefile.manual
+++ b/src/Makefile.manual
@@ -28,4 +28,4 @@ clean:
 
 # Fortran module dependencies
 f18estop.o: stdlib_experimental_error.o
-stdlib_experimental_io.o: stdlib_experimental_error.o
+stdlib_experimental_io.o: stdlib_experimental_error.o stdlib_experimental_optval.o
diff --git a/src/stdlib_experimental_io.f90 b/src/stdlib_experimental_io.f90
index 07c060300..91757f2a2 100644
--- a/src/stdlib_experimental_io.f90
+++ b/src/stdlib_experimental_io.f90
@@ -1,6 +1,7 @@
 module stdlib_experimental_io
 use iso_fortran_env, only: sp=>real32, dp=>real64, qp=>real128
 use stdlib_experimental_error, only: error_stop
+use stdlib_experimental_optval, only: optval
 implicit none
 private
 ! Public API
@@ -297,11 +298,7 @@ integer function open(filename, mode) result(u)
 character(:),allocatable :: action_, position_, status_, access_, form_
 
 
-! Note: with `optval` this could be written as:
-! mode_ = parse_mode(optval(mode, ""))
-mode_ = ""
-if (present(mode)) mode_ = mode
-mode_ = parse_mode(mode_)
+mode_ = parse_mode(optval(mode, ""))
 
 if (mode_(1:2) == 'r ') then
     action_='read'