Add a custom Sphinx extension for linking to API documentation.

Unlike extlinks, our apilinks extension knows how to format class names
for display, so we don't need to use custom titles all the time.

src/sphinx/conf.py

@@ -17,7 +17,7 @@
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = ['sphinx.ext.extlinks', 'includecode']
+extensions = ['sphinx.ext.extlinks', 'includecode', 'apilinks']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -254,6 +254,10 @@
   'ex': ('https://github.com/slick/slick-examples/blob/'+slick_examples_version+'/src/main/scala/scala/slick/examples/%s.scala', 'Slick example ')
 }
 
+apilinks = {
+  'api': 'http://slick.typesafe.com/doc/'+version+'/api/#%s'
+}
+
 rst_epilog = '''
 .. include:: %(links)s
 .. _Slick Examples: https://github.com/slick/slick-examples/tree/%(examples-version)s

src/sphinx/exts/apilinks.py

@@ -0,0 +1,37 @@
+"""
+    Based on sphinx.ext.extlinks,
+    :copyright: Copyright 2007-2011 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+from docutils import nodes, utils
+
+from sphinx.util.nodes import split_explicit_title
+
+
+def make_link_role(base_url):
+    def role(typ, rawtext, text, lineno, inliner, options={}, content=[]):
+        text = utils.unescape(text)
+        has_explicit_title, title, part = split_explicit_title(text)
+        try:
+            full_url = base_url % part
+        except (TypeError, ValueError):
+            inliner.reporter.warning(
+                'unable to expand %s apilink with base URL %r, please make '
+                'sure the base contains \'%%s\' exactly once'
+                % (typ, base_url), line=lineno)
+            full_url = base_url + part
+        if not has_explicit_title:
+            idents = part.split(".")
+            title = idents[len(idents)-1]
+        pnode = nodes.reference(title, title, internal=False, refuri=full_url)
+        return [pnode], []
+    return role
+
+def setup_link_roles(app):
+    for name, base_url in app.config.apilinks.iteritems():
+        app.add_role(name, make_link_role(base_url))
+
+def setup(app):
+    app.add_config_value('apilinks', {}, 'env')
+    app.connect('builder-inited', setup_link_roles)