Update doc and README.md

Author: ArtisticZhao

README.md

@@ -33,6 +33,10 @@ Options
 -------
 - let g:verilog_instance_skip_last_coma = {0/1}
     - When the variable is 1, last printed line will skip the coma. Default value is 0.
+- let g:verilog_instance_keep_comments = {0/1}
+    - When the variable is 1, comments will be kept (block comments /* */ not support!). Default value is 0.
+- let g:verilog_instance_keep_empty_lines = {0/1}
+    - When the variable is 1, empty lines in your code will be printed. Default value is 0.
 
 Other vim plugins for Verilog/SystemVerilog
 ---------------------------------------

doc/verilog_instance.txt

@@ -35,6 +35,16 @@ OPTIONS                                         *verilog-instance-options*
                                                 *g:verilog_instance_skip_last_coma*
         let g:verilog_instance_skip_last_coma = {0/1}
         When the variable is 1, last printed line will skip the coma.
+        The default value is 0.
+
+                                                *g:verilog_instance_keep_comments*
+        let g:verilog_instance_keep_comments = {0/1}
+        When the variable is 1, comments will be kept (block comments /* */ not support!).
+        The default value is 0.
+
+                                                *g:verilog_instance_keep_empty_lines*
+        let g:verilog_instance_keep_empty_lines = {0/1}
+        When the variable is 1, empty lines in your code will be printed.
         The default value is 0.
 
 ------------------------------------------------------------------------------

plugin/verilog_instance.py

@@ -50,6 +50,9 @@
     # get indentation length from 1st non empty line
     if indent_len == -1 and not(pattern_empty_line.match(line)):
         indent_len = len(re.match(r'^\s*', line).group(0))
+    # handle empty line
+    if pattern_empty_line.match(line) is not None:
+        contents.append('')
     # handle comments
     if wait_to_close_comment:
         if pattern_close_comment.search(line):