Become a little smarter about the area that actually changed in an edit

plugin/UltiSnips/__init__.py

@@ -794,21 +794,23 @@ class SnippetManager(object):
         self._vstate.update()
 
         if self._csnippets:
-            abs_end = self._vstate.pos
+            ct = map(as_unicode, vim.current.buffer)
-            abs_start = self._vstate.ppos
+            lt = map(as_unicode, self._lvb[:])
-            if abs_end < abs_start:
+            lt_span, ct_span  = edit_distance.line_diffs(lt, ct)
-                abs_start, abs_end = abs_end, abs_start
+            debug("lt: %r" % (lt))
-            abs_start = Position(0,0) # TODO
+            debug("ct: %r" % (ct))
-            abs_end = Position(len(vim.current.buffer)-1, 10000)
+            debug("lt_span: %r, ct_span: %r" % (lt_span, ct_span))
-            span = Span(abs_start, abs_end)
 
             # TODO
-            # ct = TextBuffer('\n'.join(vim.current.buffer))[span]
+            # start_line = min(self._vstate.pos.line, self._vstate.ppos.line)
-            # lt = self._lvb[span]
+            # ct = as_unicode('\n').join(map(as_unicode, vim.current.buffer[start_line:]))
-            ct = as_unicode('\n').join(map(as_unicode, vim.current.buffer))
+            # lt = as_unicode('\n').join(self._lvb[start_line:])
-            lt = as_unicode(self._lvb)
+            lt = '\n'.join(lt[lt_span[0]:lt_span[1]+1])
+            ct = '\n'.join(ct[ct_span[0]:ct_span[1]+1])
+            debug("lt: %r, ct: %r" % (lt, ct))
 
-            rv = edit_distance.edit_script(lt, ct, abs_start.line, abs_start.col)
+            rv = edit_distance.edit_script(lt, ct, min(lt_span[0], ct_span[0]))
+            debug("rv: %r" % (rv,))
             self._csnippets[0].edited(rv)
 
         self._check_if_still_inside_snippet()

plugin/UltiSnips/edit_distance.py

@@ -7,11 +7,66 @@ import sys
 
 # TODO: check test cases here. They are not up to date
 
-def edit_script(a, b, sline = 0, scol = 0):
+from .debug import debug
+
+def line_diffs(a, b, sline = 0):
     d = defaultdict(list)
     seen = defaultdict(lambda: sys.maxint)
 
-    d[0] = [ (0,0,sline,scol, ()) ]
+    d[0] = [ (0,0,sline, ()) ]
+    cost = 0
+    while True:
+        while len(d[cost]):
+            x, y, line, what = d[cost].pop()
+
+            if x == len(a) and y == len(b):
+                # Find first span of changes in both buffers
+                x_min, x_max = sys.maxint, -sys.maxint
+                y_min, y_max = sys.maxint, -sys.maxint
+                debug("what: %r" % (what,))
+                for cmd,x,y in what:
+                    if cmd == 'D':
+                        x_min = min(x_min, x)
+                        x_max = max(x_max, x)
+                    elif cmd == 'I':
+                        x_max = max(x_max, x-1 if x > 0 else 0)
+                        x_min = min(x_min, x-1 if x > 0 else 0)
+                        # y_min = min(y_min, line)
+                        y_min = min(y_min, y-1 if y > 0 else 0)
+                        y_max = max(y_max, y)
+                    elif cmd == "M":
+                        x_min = min(x_min, x)
+                        x_max = max(x_max, x)
+                        y_min = min(y_min, y)
+                        y_max = max(y_max, y)
+
+                return (x_min, x_max), (y_min, y_max)
+
+            # TODO: line == y
+            if x < len(a) and y < len(b) and len(a[x]) == len(b[y]) and \
+                a[x] == b[y]: # Equal lines
+                if seen[x+1,y+1] > cost:
+                    seen[x+1,y+1] = cost
+                    if x != y:
+                        d[cost].append((x+1,y+1,line+1, what + (('M', x,y),))) # TODO: match only debug
+                    else:
+                        d[cost].append((x+1,y+1,line+1, what)) # TODO: match only debug
+            if x < len(a): # Delete
+                if seen[x+1,y] > cost + 1 + x:
+                    seen[x+1,y] = cost + 1 + x
+                    d[cost+1+x].append((x+1,y, line, what + (('D', x, y),)))
+            if y < len(b): # Insert
+                if seen[x,y+1] > cost + 1 + y:
+                    seen[x,y+1] = cost + 1 + y
+                    d[cost+1+y].append((x,y+1,line+1, what + (('I', x, y),)))
+        cost += 1
+
+
+def edit_script(a, b, sline = 0):
+    d = defaultdict(list)
+    seen = defaultdict(lambda: sys.maxint)
+
+    d[0] = [ (0,0,sline, 0, ()) ]
 
     # TODO: needs some doku
     cost = 0
@@ -23,7 +78,7 @@ def edit_script(a, b, sline = 0, scol = 0):
             #print "%r: %r" % (cost, sumarized)
             x, y, line, col, what = d[cost].pop()
 
-            if a[x:] == b[y:]: ## TODO: try out is
+            if a[x:] == b[y:]:
                 #print "cost: %r" % (cost)
                 return what