Added support for overwriting of previous snippet definitions

doc/UltiSnips.txt

@@ -141,11 +141,23 @@ specified.
 
 The snippets file format is simple. A line starting with # is a comment, each
 snippet starts with a line in the form of: >
-   snippet tab_trigger "description"
+   snippet tab_trigger [ "description" [ options ] ]
 The following lines are the snippets definition; a line starting with >
    endsnippet
 marks the end of the snippet. The trailing newline is chopped from the
-definition.
+definition. In the starting line, the description and options are optional.
+
+The description is only needed when more than one snippet is defined with the
+same tab trigger. The user is then given a choice and the description is
+displayed for the user as helper. 
+
+The options is a word of characters, each turning a specific option for this
+snippet on. The options currently supported are >
+   !   Overwrite - This snippet will overwrite all previously defined
+       snippets with this tab trigger. Default is to let the user choose at
+       expansion which snippet to expand. This option is useful to overwrite
+       bundled tab stops with user defined ones.
+
 
 4.2 Plaintext snippets                         *UltiSnips-plaintext-snippets*
 ----------------------

plugin/UltiSnips/__init__.py

@@ -14,10 +14,15 @@ from UltiSnips.Buffer import VimBuffer
 class Snippet(object):
     _INDENT = re.compile(r"^[ \t]*")
 
-    def __init__(self,trigger,value, descr):
+    def __init__(self, trigger, value, descr, options):
         self._t = trigger
         self._v = value
         self._d = descr
+        self._overwrites = "!" in options
+
+    def overwrites_previous(self):
+        return self._overwrites
+    overwrites_previous = property(overwrites_previous)
 
     def value(self):
         return self._v
@@ -170,11 +175,11 @@ class SnippetManager(object):
         self._expect_move_wo_change = False
 
 
-    def add_snippet(self, trigger, value, descr):
+    def add_snippet(self, trigger, value, descr, options):
         if "all" not in self._snippets:
             self._snippets["all"] = {}
         l = self._snippets["all"].get(trigger,[])
-        l.append(Snippet(trigger,value, descr))
+        l.append(Snippet(trigger,value, descr, options))
         self._snippets["all"][trigger] = l
 
     def jump(self, backwards = False):
@@ -220,6 +225,12 @@ class SnippetManager(object):
         for ft in filetypes:
             snippets += self._find_snippets(ft, word)
 
+        # Search if any of the snippets overwrites the previous
+        for idx in range(len(snippets)-1,-1,-1):
+            if snippets[idx].overwrites_previous:
+                snippets = snippets[idx:]
+                break
+
         if not len(snippets):
             # No snippet found
             return False
@@ -419,6 +430,7 @@ class SnippetManager(object):
         cs = None
         cv = ""
         cdescr = ""
+        coptions = ""
         for line in open(fn):
             if cs is None and line.startswith("#"):
                 continue
@@ -428,15 +440,15 @@ class SnippetManager(object):
                 if left != -1:
                     right = line.rfind('"')
                     cdescr = line[left+1:right]
+                    coptions = line[right:].strip()
                 continue
             if cs != None:
                 if line.startswith("endsnippet"):
                     cv = cv[:-1] # Chop the last newline
                     l = self._snippets[ft].get(cs,[])
-                    l.append(Snippet(cs,cv,cdescr))
+                    l.append(Snippet(cs,cv,cdescr,coptions))
                     self._snippets[ft][cs] = l
-                    cv = ""
-                    cdescr = ""
+                    cv = cdescr = coptions = ""
                     cs = None
                     continue
                 else:

test.py

@@ -74,13 +74,19 @@ class _VimTest(unittest.TestCase):
         for s in self.snippets:
             sv,content = s[:2]
             descr = ""
-            if len(s) == 3:
-                descr = s[-1]
+            options = ""
+            if len(s) > 2:
+                descr = s[2]
+            if len(s) > 3:
+                options = s[3]
+
             self.send(''':py << EOF
-UltiSnips_Manager.add_snippet("%s","""%s""", "%s")
+UltiSnips_Manager.add_snippet("%s","""%s""", "%s", "%s")
 EOF
-''' % (sv,content.encode("string-escape"), descr.encode("string-escape"))
-            )
+''' % (sv,content.encode("string-escape"), descr.encode("string-escape"),
+      options
+      )
+      )
 
         # Clear the buffer
         self.send("bggVGd")
@@ -938,6 +944,36 @@ class Completion_SimpleExample_ECR(_VimTest):
             "superkallifragilistik some more"
 
 
+###################
+# SNIPPET OPTIONS #
+###################
+class SnippetOptions_OverwriteExisting_ECR(_VimTest):
+    snippets = (
+     ("test", "${1:Hallo}", "Types Hallo"),
+     ("test", "${1:World}", "Types World"),
+     ("test", "We overwrite", "Overwrite the two", "!"),
+    )
+    keys = "test" + EX
+    wanted = "We overwrite"
+class SnippetOptions_OverwriteTwice_ECR(_VimTest):
+    snippets = (
+        ("test", "${1:Hallo}", "Types Hallo"),
+        ("test", "${1:World}", "Types World"),
+        ("test", "We overwrite", "Overwrite the two", "!"),
+        ("test", "again", "Overwrite again", "!"),
+    )
+    keys = "test" + EX
+    wanted = "again"
+class SnippetOptions_OverwriteThenChoose_ECR(_VimTest):
+    snippets = (
+        ("test", "${1:Hallo}", "Types Hallo"),
+        ("test", "${1:World}", "Types World"),
+        ("test", "We overwrite", "Overwrite the two", "!"),
+        ("test", "No overwrite", "Not overwritten", ""),
+    )
+    keys = "test" + EX + "1\n\n" + "test" + EX + "2\n"
+    wanted = "We overwrite\nNo overwrite"
+
 
 ######################
 # SELECTING MULTIPLE #