Patch to add type inference and definition popups to Sublime Text's Merlin plugin

merlin-sublime-popups.patch

diff --git a/Packages/Merlin/sublime-text-merlin.py b/Packages/Merlin/sublime-text-merlin.py
--- a/Packages/Merlin/sublime-text-merlin.py
+++ b/Packages/Merlin/sublime-text-merlin.py
@@ -248,6 +248,57 @@
             else:
                 opened_view.run_command("insert_code", { "arg": sig })
 
+class MerlinInfoPopup:
+    """
+    Pop up a menu at a point describing an expression
+    """
+
+    def __init__(self, view, point):
+        merlin = merlin_view(view)
+        merlin.sync()
+
+        line, col = view.rowcol(point)
+
+        # FIXME: proper integration into sublime-text
+        # enclosing is a list of json objects of the form:
+        # { 'type': string;
+        #   'tail': "no"|"position"|"call" // tailcall information
+        #   'start', 'end': {'line': int, 'col': int}
+        # }
+        self.enclosing = merlin.type_enclosing(line + 1, col)
+        self.declaration = merlin.locate(line + 1, col, kind="mli")
+        self.definition = merlin.locate(line + 1, col, kind="ml")
+        self.view = view
+        self.point = point
+
+    def _type_str(self):
+        if len(self.enclosing) > 0:
+            return clean_whitespace(self.enclosing[0]['type'])
+        else:
+            return ""
+
+    def _loc_link(self, loc):
+        if isinstance(loc, dict):
+            pos = loc['pos']
+            if 'file' in loc:
+                short_file = os.path.basename(loc['file'])
+                filename = "%s:%d:%d" % (loc.get('file',''), pos['line'], pos['col'] + 1)
+                return "<a href=\"{}\">{}:{}</a>".format(filename, short_file,pos['line'])
+            else:
+                return "[this file]:" + pos['line']
+        else:
+            return ""+loc
+
+    def show_popup(self):
+        print('showing popup')
+        content = "<b>Definition:</b> {} <br><b>Declaration:</b> {}<br><b>Type:</b><br> {}".format(self._loc_link(self.definition),self._loc_link(self.declaration), self._type_str())
+        self.view.show_popup(content,
+            sublime.HIDE_ON_MOUSE_MOVE_AWAY, self.point,
+            600,150, self.on_navigate)
+
+    def on_navigate(self, href):
+        self.view.window().open_file(href, sublime.ENCODED_POSITION)
+
 class InsertCodeCommand(sublime_plugin.TextCommand):
     def run(self, edit, arg):
         self.view.insert(edit, self.view.size(), arg)
@@ -735,6 +786,11 @@
         view.erase_regions('ocaml-underlines-errors')
         #merlin_error_panel.close()
 
+    @only_ocaml
+    def on_hover(self, view, point, hover_zone):
+        if hover_zone == sublime.HOVER_TEXT:
+            popup = MerlinInfoPopup(view, point)
+            popup.show_popup()
 
     def _plugin_dir(self):
         path = os.path.realpath(__file__)