lib/mp-readline: Add word-based move/delete EMACS key sequences.

This commit adds backward-word, backward-kill-word, forward-word,
forward-kill-word sequences for the REPL, with bindings to Alt+F, Alt+B,
Alt+D and Alt+Backspace respectively.  It is disabled by default and can be
enabled via MICROPY_REPL_EMACS_WORDS_MOVE.

Further enabling MICROPY_REPL_EMACS_EXTRA_WORDS_MOVE adds extra bindings
for these new sequences: Ctrl+Right, Ctrl+Left and Ctrl+W.

The features are enabled on unix micropython-coverage and micropython-dev.

5 files changed, 95 insertions, 1 deletions

diff --git a/tests/cmdline/repl_words_move.py b/tests/cmdline/repl_words_move.py
new file mode 100644
index 000000000..e1eb52953
--- /dev/null
+++ b/tests/cmdline/repl_words_move.py
@@ -0,0 +1,31 @@
+# word movement
+# backward-word, start in word
+234b1
+# backward-word, don't start in word
+234    b1
+# backward-word on start of line. if cursor is moved, this will result in a SyntaxError
+1 2 + 3
b+
+# forward-word, start in word
+1+2 12+f+3
+# forward-word, don't start in word
+1+    12 3
f+
+# forward-word on eol. if cursor is moved, this will result in a SyntaxError
+1 + 2 3f+
+
+# kill word
+# backward-kill-word, start in word
+100 + 45623
+# backward-kill-word, don't start in word
+100 + 456231
+# forward-kill-word, start in word
+100 + 256d3
+# forward-kill-word, don't start in word
+1 + 256d2
+
+# extra move/kill shortcuts
+# ctrl-left
+2341
+# ctrl-right
+123
+# ctrl-w
+1231
diff --git a/tests/cmdline/repl_words_move.py.exp b/tests/cmdline/repl_words_move.py.exp
new file mode 100644
index 000000000..86f6b7788
--- /dev/null
+++ b/tests/cmdline/repl_words_move.py.exp
@@ -0,0 +1,47 @@
+MicroPython \.\+ version
+Use \.\+
+>>> # word movement
+>>> # backward-word, start in word
+>>> \.\+
+1234
+>>> # backward-word, don't start in word
+>>> \.\+
+1234
+>>> # backward-word on start of line. if cursor is moved, this will result in a SyntaxError
+>>> \.\+
+6
+>>> # forward-word, start in word
+>>> \.\+
+18
+>>> # forward-word, don't start in word
+>>> \.\+
+16
+>>> # forward-word on eol. if cursor is moved, this will result in a SyntaxError
+>>> \.\+
+6
+>>> 
+>>> # kill word
+>>> # backward-kill-word, start in word
+>>> \.\+
+123
+>>> # backward-kill-word, don't start in word
+>>> \.\+
+101
+>>> # forward-kill-word, start in word
+>>> \.\+
+123
+>>> # forward-kill-word, don't start in word
+>>> \.\+
+3
+>>> 
+>>> # extra move/kill shortcuts
+>>> # ctrl-left
+>>> \.\+
+1234
+>>> # ctrl-right
+>>> \.\+
+123
+>>> # ctrl-w
+>>> \.\+
+1
+>>> 
diff --git a/tests/feature_check/repl_words_move_check.py b/tests/feature_check/repl_words_move_check.py
new file mode 100644
index 000000000..e74615e98
--- /dev/null
+++ b/tests/feature_check/repl_words_move_check.py
@@ -0,0 +1,4 @@
+# just check if ctrl+w is supported, because it makes sure that
+# both MICROPY_REPL_EMACS_WORDS_MOVE and MICROPY_REPL_EXTRA_WORDS_MOVE are enabled.
+t = 1231
+t == 1
diff --git a/tests/feature_check/repl_words_move_check.py.exp b/tests/feature_check/repl_words_move_check.py.exp
new file mode 100644
index 000000000..82a4e28ee
--- /dev/null
+++ b/tests/feature_check/repl_words_move_check.py.exp
@@ -0,0 +1,7 @@
+MicroPython \.\+ version
+Use \.\+
+>>> # Check for emacs keys in REPL
+>>> t = \.\+
+>>> t == 2
+True
+>>> 
diff --git a/tests/run-tests b/tests/run-tests
index b02463dc3..b8f5b6b7a 100755
--- a/tests/run-tests
+++ b/tests/run-tests
@@ -284,9 +284,14 @@ def run_tests(pyb, tests, args, base_path="."):
 
         # Check if emacs repl is supported, and skip such tests if it's not
         t = run_feature_check(pyb, args, base_path, 'repl_emacs_check.py')
-        if not 'True' in str(t, 'ascii'):
+        if 'True' not in str(t, 'ascii'):
             skip_tests.add('cmdline/repl_emacs_keys.py')
 
+        # Check if words movement in repl is supported, and skip such tests if it's not
+        t = run_feature_check(pyb, args, base_path, 'repl_words_move_check.py')
+        if 'True' not in str(t, 'ascii'):
+            skip_tests.add('cmdline/repl_words_move.py')
+
         upy_byteorder = run_feature_check(pyb, args, base_path, 'byteorder.py')
         upy_float_precision = run_feature_check(pyb, args, base_path, 'float.py')
         if upy_float_precision == b'CRASH':