Implement basic :s[ubstitute] command

Author: lieryan

pyvim/commands/commands.py

@@ -1,6 +1,9 @@
 from __future__ import unicode_literals, print_function
 from prompt_toolkit.application import run_in_terminal
+from prompt_toolkit.document import Document
+
 import os
+import re
 import six
 
 __all__ = (
@@ -704,3 +707,26 @@ def set_scroll_offset(editor, value):
             'Invalid value. Expecting comma separated list of integers')
     else:
         editor.colorcolumn = numbers
+
+
+def substitute(editor, range_start, range_end, search, replace, flags):
+    if flags == 'g':
+        transform_callback = lambda s: re.sub(search, replace, s)
+    else:
+        transform_callback = lambda s: re.sub(search, replace, s, count=1)
+
+    buffer = editor.current_editor_buffer.buffer
+    current_row = buffer.document.cursor_position_row
+
+    if not range_end:
+        range_end = range_start
+    if range_start and range_end:
+        line_index_iterator = range(int(range_start) - 1, int(range_end))
+    else:
+        line_index_iterator = range(current_row, current_row + 1)
+
+    new_text = buffer.transform_lines(line_index_iterator, transform_callback)
+    buffer.document = Document(
+        new_text,
+        Document(new_text).translate_row_col_to_index(current_row, 0))
+    buffer.cursor_position += buffer.document.get_start_of_line_position(after_whitespace=True)

pyvim/commands/grammar.py

@@ -11,6 +11,9 @@
     :*
     \s*
     (
+        # Substitute command
+        ((?P<range_start>\d+)(,(?P<range_end>\d+))?)?  (?P<command>s|substitute) \s* / (?P<search>[^/]*) / (?P<replace>[^/]*) (?P<flags> /g )?    |
+
         # Commands accepting a location.
         (?P<command>%(commands_taking_locations)s)(?P<force>!?)  \s+   (?P<location>[^\s]+)   |
 

pyvim/commands/handler.py

@@ -1,7 +1,7 @@
 from __future__ import unicode_literals
 
 from .grammar import COMMAND_GRAMMAR
-from .commands import call_command_handler, has_command_handler
+from .commands import call_command_handler, has_command_handler, substitute
 
 __all__ = (
     'handle_command',
@@ -21,6 +21,11 @@ def handle_command(editor, input_string):
     command = variables.get('command')
     go_to_line = variables.get('go_to_line')
     shell_command = variables.get('shell_command')
+    range_start = variables.get('range_start')
+    range_end = variables.get('range_end')
+    search = variables.get('search')
+    replace = variables.get('replace')
+    flags = variables.get('flags', '')
 
     # Call command handler.
 
@@ -35,6 +40,11 @@ def handle_command(editor, input_string):
     elif has_command_handler(command):
         # Handle other 'normal' commands.
         call_command_handler(command, editor, variables)
+
+    elif command in ('s', 'substitute'):
+        flags = flags.lstrip('/')
+        substitute(editor, range_start, range_end, search, replace, flags)
+
     else:
         # For unknown commands, show error message.
         editor.show_message('Not an editor command: %s' % input_string)