toggle_symbol.py

import sublime_plugin
import re
import string
from sublime import Region

re_quotes = re.compile("^(['\"])(.*)\\1$")
re_symbol = re.compile("^(\:)(.*)$")

class ToggleSymbolCommand(sublime_plugin.TextCommand):

  def matcher(self,text):
    res = re_quotes.match(text)
    if not res:
      res = re_symbol.match(text)
    return res

  def replacer(self, v, edit, sel, text, res):
    old_quotes = res.group(1)
    text = res.group(2)

    if old_quotes == ':':
      text = "'" + text + "'"
    elif old_quotes == "'":
      text = '"' + text + '"'
    else :
      text = ':' + text

    v.replace(edit, sel, text)


  def run(self, edit):
    v = self.view
    if v.sel()[0].size() == 0:
        v.run_command("expand_selection", {"to": "word"})

    cur_start = v.sel()[0].begin()
    cur_end = v.sel()[0].end()

    for sel in v.sel():
        text = v.substr(sel)
        res = self.matcher(text)
        
        if not res:
          #first check one character to the left to see if its a symbol
          sel = Region(sel.begin() - 1, sel.end())
          text = v.substr(sel)
          res = self.matcher(text)

          if not res:
            #now expand selection one character to the right to see if its a string
            sel = Region(sel.begin(), sel.end() + 1)
            text = v.substr(sel)
            res = self.matcher(text)

            if not res:
              #this is a mute point
              continue

        self.replacer(v, edit, sel, text, res)

    v.sel().clear()
    v.sel().add(Region(cur_start, cur_end))

# 'dude'
# "dude"
# :dude