It's getting a little chaotic. Needs better error messages!

README.markdown

@@ -34,11 +34,16 @@ TODO
 For 0.6:
 
 *   `call` vector (generates an JSR to a trampoline that does indirect JMP.)
-*   `goto` (tail call) a routine or a vector.
-*   A more involved demo for the C64 — one that sets up an interrupt?
+*   `goto` (tail call) a a vector.
+*   add routine name to error messages.
+*   routines shouldn't need to be listed as inputs.
 
 For 0.7:
 
+*   A more involved demo for the C64 — one that sets up an interrupt?
+
+For 0.8:
+
 *   `word` type.
 *   `trash` instruction.
 *   zero-page memory locations.
@@ -47,7 +52,6 @@ For 0.7:
 At some point...
 
 *   `interrupt` routines.
-*   add line number (or at least routine name) to error messages.
 *   6502-mnemonic aliases (`sec`, `clc`)
 *   other handy aliases (`eq` for `z`, etc.)
 *   have `copy` instruction able to copy a constant to a user-def mem loc, etc.

src/sixtypical/analyzer.py

@@ -153,11 +153,12 @@ class Analyzer(object):
         type = routine.location.type
         context = Context(type.inputs, type.outputs, type.trashes)
         self.analyze_block(routine.block, context, routines)
-        for ref in type.outputs:
-            context.assert_meaningful(ref, exception_class=UninitializedOutputError)
-        for ref in context.each_touched():
-            if ref not in type.outputs and ref not in type.trashes:
-                raise IllegalWriteError(ref.name)
+        if not self.has_encountered_goto:
+            for ref in type.outputs:
+                context.assert_meaningful(ref, exception_class=UninitializedOutputError)
+            for ref in context.each_touched():
+                if ref not in type.outputs and ref not in type.trashes:
+                    raise IllegalWriteError(ref.name)
         self.current_routine = None
 
     def analyze_block(self, block, context, routines):

tests/SixtyPical Analysis.md

@@ -1134,7 +1134,7 @@ Indirect call.
     | }
     = ok
 
-Calling the vector has indeed trashed stuff etc,
+Calling the vector does indeed trash the things the vector says it does.
 
     | vector foo trashes x, z, n
     | 
@@ -1220,3 +1220,52 @@ Can't `goto` a routine that outputs or trashes more than the current routine.
     |     goto bar
     | }
     ? IncompatibleConstraintsError
+
+Can `goto` a routine that outputs or trashes less than the current routine.
+
+    | routine bar trashes x, z, n {
+    |     ld x, 1
+    | }
+    | 
+    | routine main trashes a, x, z, n {
+    |     ld a, 0
+    |     ld x, 0
+    |     goto bar
+    | }
+    = ok
+
+Indirect goto.
+
+    | vector foo outputs x trashes a, z, n
+    | 
+    | routine bar outputs x trashes a, z, n {
+    |     ld x, 200
+    | }
+    | 
+    | routine main inputs bar outputs x trashes foo, a, z, n {
+    |     copy bar, foo
+    |     goto foo
+    | }
+    = ok
+
+Jumping through the vector does indeed output the things the vector says it does.
+
+    | vector foo trashes a, x, z, n
+    | 
+    | routine bar trashes a, x, z, n {
+    |     ld x, 200
+    | }
+    | 
+    | routine sub inputs bar trashes foo, a, x, z, n {
+    |     ld x, 0
+    |     copy bar, foo
+    |     goto foo
+    | }
+    | 
+    | routine main inputs bar outputs a trashes z, n {
+    |     call sub
+    |     ld a, x
+    | }
+    ? UninitializedOutputError: x
+
+Ack, I have become a bit confused...