Add helpers to escape markdown and mentions from text.

Fixes #1673

3 files changed, 47 insertions, 6 deletions

diff --git a/discord/ext/commands/converter.py b/discord/ext/commands/converter.py
index 8676329c..0ca9096b 100644
--- a/discord/ext/commands/converter.py
+++ b/discord/ext/commands/converter.py
@@ -474,14 +474,10 @@ class clean_content(Converter):
         result = pattern.sub(repl, argument)
 
         if self.escape_markdown:
-            result = re.sub(r'\\', r'\\\\', result)
-            for c in ('*', '`', '_', '~', '|'):
-                regex = r'\{0}(?=([\s\S]*((?<!\{0})\{0})))'.format(c)
-                replace = '\{0}'.format(c)
-                result = re.sub(regex, replace, result)
+            result = discord.utils.escape_markdown(result)
 
         # Completely ensure no mentions escape:
-        return re.sub(r'@(everyone|here|[!&]?[0-9]{17,21})', '@\u200b\\1', result)
+        return discord.utils.escape_mentions(result)
 
 class _Greedy:
     __slots__ = ('converter',)
diff --git a/discord/utils.py b/discord/utils.py
index 96a26918..e277e56c 100644
--- a/discord/utils.py
+++ b/discord/utils.py
@@ -366,3 +366,43 @@ def resolve_invite(invite):
             return m.group(1)
     return invite
 
+_MARKDOWN_ESCAPE_SUBREGEX = '|'.join(r'\{0}(?=([\s\S]*((?<!\{0})\{0})))'.format(c)
+                                     for c in ('*', '`', '_', '~', '|'))
+
+_MARKDOWN_ESCAPE_REGEX = re.compile('(%s)' % _MARKDOWN_ESCAPE_SUBREGEX)
+
+def escape_markdown(text):
+    """A helper function that escapes Discord's markdown.
+
+    Parameters
+    -----------
+    text: :class:`str`
+        The text to escape markdown from.
+
+    Returns
+    --------
+    :class:`str`
+        The text with the markdown special characters escaped with a slash.
+    """
+
+    text = re.sub(r'\\', r'\\\\', text)
+    return _MARKDOWN_ESCAPE_REGEX.sub(r'\\\1', text)
+
+def escape_mentions(text):
+    """A helper function that escapes everyone, here, role, and user mentions.
+
+    .. note::
+
+        This does not include channel mentions.
+
+    Parameters
+    -----------
+    text: :class:`str`
+        The text to escape mentions from.
+
+    Returns
+    --------
+    :class:`str`
+        The text with the mentions removed.
+    """
+    return re.sub(r'@(everyone|here|[!&]?[0-9]{17,21})', r'@\u200b\1', text)
diff --git a/docs/api.rst b/docs/api.rst
index 7ba1a996..9208dafd 100644
--- a/docs/api.rst
+++ b/docs/api.rst
@@ -583,6 +583,11 @@ Utility Functions
 
 .. autofunction:: discord.utils.oauth_url
 
+.. autofunction:: discord.utils.escape_markdown
+
+.. autofunction:: discord.utils.escape_mentions
+
+
 Application Info
 ------------------