look up macro defns

--HG--
branch : pmacs2

mode/tal.py

@@ -109,6 +109,42 @@ class Taldoc(Method):
         '\'': 'raw character',
         '\"': 'raw word',
     }
+    def find_macro(self, name, w):
+        toks = w.get_highlighter().tokens
+        target = '%' + name
+        found = False
+        start = None
+        end = None
+        defn = None
+        for line in toks:
+            for t in line:
+                if not found:
+                    found = t.name == "tal.defmacro" and t.string == target
+                elif start is None:
+                    if t.name == 'delimiter' and t.string == '{':
+                        start = (t.x + 1, t.y)
+                elif end is None:
+                    if t.name == 'delimiter' and t.string == '}':
+                        end = (t.x, t.y)
+                        break
+        if start is None or end is None:
+            return None
+        (sx, sy) = start
+        (ex, ey) = end
+        lines = w.buffer.lines
+        if sy == ey:
+            # 1 lines
+            return lines[sy][sx:ex]
+        elif sy == ey + 1:
+            # 2 lines
+            return lines[sy][sx:] + ' ' + lines[ey][:e.x]
+        else:
+            # 3+ lines
+            out = []
+            out.append(lines[sy][sx:])
+            out.extend(lines[sy+1:ey])
+            out.append(lines[ey][:ex])
+            return ' '.join(out)
     def _execute(self, w, **vargs):
         tok = w.get_token()
         word = tok.string
@@ -145,7 +181,11 @@ class Taldoc(Method):
             kind = self.addr_dict.get(word[0], 'unknown address')
             w.set_error('%r is a %s' % (word, kind))
         else:
+            defn = self.find_macro(word, w)
+            if defn is None:
                 w.set_error('%r is not recognized' % word)
+            else:
+                w.set_error('%r is a macro: %s' % (word, defn))
 
 
 class Tal(Fundamental):