X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=TODO;h=c7ad150a242c07c529b5ec58bbbccdae6117e708;hp=118520951f00698612b7fb4c1cb1d2465e597861;hb=14e2fc1b5414cbc270b81b12e47b149ad3275a49;hpb=77d1e5fd29be1ca529e71a4c011f5edea61588e8

diff --git a/TODO b/TODO
index 1185209..c7ad150 100644
--- a/TODO
+++ b/TODO
@@ -1,58 +1,41 @@
-// priorities are all messy and dont get serialized
-// 1. Error messages
-// 2. Java MetaGrammar (proof of concept)
-// 3. Ivan's MetaGrammar
-// 4. Documentation format
-//       - TIB
-
-// TODO: better API for interfacing with Java
-// TODO: error messages
-// TODO: integrate with TIB
-
-// Element
-// Walk
-// ParseTable / GSS
-// MetaGrammar (necessary/relevant?)
-// Tree<String> (cleanup?)
-// Union.SubUnion
-// Repeat
-
-// FEATURE: serialization of ParseTable's, generation of Java code
-// FEATURE: infer reject elements for literals
-// FEATURE: prefer whitespace higher up
-// FEATURE: full conjunctive and boolean grammars
-// FEATURE: "ambiguity modulo dropped fragments"?  can this be checked for statically?  eliminated statically?
-//            - drop stuff during the parsing process (drop nodes)
-
-// LATER: Element<A> -- parameterize over the input token type?  Makes a huge mess...
-// LATER: Go back to where Sequence is not an Element?
-//            - The original motivation for making Sequence "first class" was the fact that 
-//              in order to do associativity right you need to have per-Sequence follow sets
-
-______________________________________________________________________________
+_____________________________________________________________________________
 Immediately
 
-  - switch maximal to not-followed-by (~/~)
+  - Performance
+
+     - Forest: keep() and valid() -- can we do this with states
+       rather than subtrees?
+
+     - hash Long->long: it's all bogus
+
+  * pick back up cleaning up end of Parser.java (Reduction)
+
+  - [more] sensible tree-printout
+
+  - revamp Tib.Block (do it all in the parser using indent/dedent?)
+
+  - more natural phrasing of metagrammar?
+  - finalize metagrammar and rdp-op's
 
   - should Union.add() be there?
   - should Atom.top() be there?
 
-  - fix the location stuff, it's broken
   - decent/better error messages
+      - fix the location stuff, it's broken
 
   - write some grammars
       - Java grammar
       - TeX (math?)
       - URL (RFC)
       - RFC2822 (email message/headers)
-      - Wiki grammar
+
 
 ______________________________________________________________________________
 Soon
 
-  - clean up the whole Walk situation
+  - substring parsing for better error messages
 
-  - cleaner solution to "maximal"?
+  - clean up the whole Walk situation
 
   - "lift" cases:
       - right now I can only lift the last child in a forest...  begs
@@ -63,9 +46,18 @@ Soon
   - "Regular Right Part" grammars (NP Chapman, etc)
   - Attribute unification
 
+  - serialization of parse tables
+  - inference of rejections for literals
+  - "prefer whitespace higher up" (?)
+  - "ambiguity modulo dropped fragments"?
+       - can this be checked statically?
+       - eliminated statically?
+
 ______________________________________________________________________________
 Later
 
+  - Partly-Linear-PATR? (O(n^6) unification grammar)
+
   - Implement a k-token peek buffer (for each state, see if it "dead
     ends" during the next k Phases based solely on state -- ignoring
     result SPPF)
@@ -77,11 +69,6 @@ Later
     nodes which are transient in the sense that they have only one
     eligible reduction?
 
-  - Implement "GLR syntactic predicates" -- the ability to do
-    arbitrary lookahead (ie "followed-by" and "not-followed-by" for
-    arbitrary patterns).  This enables generalized longest-match and
-    lets us drop the Maximal hack.
-
   - Re-read Rekers, particularly the stuff on optimal sharing
 
   - Isolate the Element objects from Parse.Table/GSS so we can move
@@ -138,3 +125,23 @@ Later
   - implement Johnstone's algorithm for "reduced, resolved LR
     tables" to eliminate superfluous reductions on
     epsilon-transitions.
+
+______________________________________________________________________________
+Neat Ideas
+
+  - Rekers & Koorn note that GLR Substring Parsing can be used to do
+    really elegant and generalized "autocompletion".
+
+
+______________________________________________________________________________
+Ideas for the Future
+
+- Incremental parse table construction
+- "lazy GLR" and "lazy trees" -> language with first-class CF matching
+    - perhaps linear boolean grammars instead? (linear time, quad space)
+- Forest parsing => chained parsers
+- unification parsing, attributes, etc
+- RRP grammars?
+- Take another stab at maximal-match?  Nonterminal not-followed-by is
+  too strong.
+- Error recovery based on substring parsing