py: Add stream reading of n unicode chars; unicode support by default.

With unicode enabled, this patch allows reading a fixed number of
characters from text-mode streams; eg file.read(5) will read 5 unicode
chars, which can made of more than 5 bytes.

For an ASCII stream (ie no chars > 127) it only needs to do 1 read.  If
there are lots of non-ASCII chars in a stream, then it needs multiple
reads of the underlying object.

Adds a new test for this case.  Enables unicode support by default on
unix and stmhal ports.

3 files changed, 14 insertions, 1 deletions

diff --git a/tests/run-tests b/tests/run-tests
index 71a94f946f..4b48421ded 100755
--- a/tests/run-tests
+++ b/tests/run-tests
@@ -134,7 +134,7 @@ def main():
         if args.test_dirs is None:
             if pyb is None:
                 # run PC tests
-                test_dirs = ('basics', 'micropython', 'float', 'import', 'io', 'misc')
+                test_dirs = ('basics', 'micropython', 'float', 'import', 'io', 'misc', 'unicode')
             else:
                 # run pyboard tests
                 test_dirs = ('basics', 'micropython', 'float', 'pyb', 'pybnative', 'inlineasm')
diff --git a/tests/unicode/data/utf-8_2.txt b/tests/unicode/data/utf-8_2.txt
new file mode 100644
index 0000000000..ab0eaa4e0d
--- /dev/null
+++ b/tests/unicode/data/utf-8_2.txt
@@ -0,0 +1 @@
+aαbβcγdδ
diff --git a/tests/unicode/file2.py b/tests/unicode/file2.py
new file mode 100644
index 0000000000..aca2e0e0ed
--- /dev/null
+++ b/tests/unicode/file2.py
@@ -0,0 +1,12 @@
+# test reading a given number of characters
+
+def do(mode):
+    f = open('unicode/data/utf-8_2.txt', mode)
+    print(f.read(1))
+    print(f.read(1))
+    print(f.read(2))
+    print(f.read(4))
+    f.close()
+
+do('rb')
+do('rt')