1 _____________________________________________________________________________
4 - clean up util package
6 - currently we GC the doomed stack when the parent dies... but
7 [ideally] we should also GC the parent when the doomed stack dies
8 if it was a positive conjunct.
10 - single-tree-return assumption
11 - have a way to let question marks not be tagged?
12 - "flat" sequences (no subtrees contain "::"s?) -- stringifiable
13 - make it so that we can have multi-result nonterminals
14 so long as they always appear under double-colons?
15 auto-insert the unwrap?
17 - get rid of Sequence.Singleton if possible
19 - use 'a'-'z' or 'a-z' instead of [a-z]?
22 foo.add(y.andnot(x)) ==> this is broken
23 - distinguish Conjunct from Sequence?
24 => !(Conjunct instanceof Reducible)
25 - avoid building the parts of the tree that end up getting dropped
26 - is it worth adding an additional class of states for these?
27 - or perhaps just a runtime node marker (hasNonDroppedParent)
28 - "ambiguity modulo dropped fragments"?
29 - this may conceal highly inefficient grammars...
30 - double-check all the region logic
31 - automatically collect time statistics and display
33 ______________________________________________________________________________
36 - use regression/least-squares/trend-prof to look for reductions whose
37 behavior is O(n^2)? (ie performed a number of times proportional to
38 the input consumed so far).
43 - don't form result forests for negated productions
44 - early kills: (a &~ ... b ...) -> once "... b" is seen, "a" is dead
46 - MUST HAVE BETTER ERROR MESSAGES
47 - use for developing java15.g
48 - better ambiguity reporting
49 - colorized tree-diffs?
51 - better toString() methods all around...
53 - Treewalker code compiler?
54 - detect and reject circular gramars
56 - precedes restrictions ("<-")
57 - More topology untangling [later]
58 - grammar highlighting?
59 - Forest needs a "manual access" API (lifting makes this hard)
60 - rewriting language? multiple passes?
62 - Java grammar (java15.g)
64 - RFC2822 (email message/headers)
65 - Wikipedia grammar (needs to be both lexerless and boolean)
68 ______________________________________________________________________________
71 - try harder to "fuse" states together along two dimensions:
72 - identical (equivalent) states, or states that subsume each other
73 - unnecessary intermediate states ("short cut" GLR)
76 - better error messages
77 - Rekers & Koorn note that this can do really elegant and generalized "autocompletion".
79 - "Regular Right Part" grammars (NP Chapman, etc)
80 - Attribute unification
81 - Partly-Linear-PATR? (O(n^6) unification grammar)
83 - optional "prefer whitespace higher up" disambiguation heuristic
85 - Incremental parse table construction
87 - "lazy GLR" and "lazy trees" -> language with first-class CF matching
88 - perhaps linear boolean grammars instead? (linear time, quad space)
90 - Followed-by and not-followed-by predicates of arbitrary length
91 - expands the grammar beyond Boolean LR...
92 - requires *very* smart garbage collection
94 ______________________________________________________________________________
97 - understand and implement the RNGLR "kernel state" optimization.
98 The _Practical Early Parsing_ paper may help.
100 - implement Johnstone's algorithm for "reduced, resolved LR
101 tables" to eliminate superfluous reductions on
104 - Implement a k-token peek buffer (for each state, see if it "dead
105 ends" during the next k Phases based solely on state -- ignoring
108 - Is there any way we can avoid creating a GSS.Node instance for
109 nodes which are transient in the sense that they have only one
112 - Re-read Rekers, particularly the stuff on optimal sharing
114 - bring back in parse-table phase resolution of precedence (just
115 like associativity). This can be inferred from the use of ">"
116 when the rules are in one of these special forms:
127 where "_" is anything and "E" is the defining nonterminal.
128 Essentially what we're looking for is the situation where the
129 leftmost portion of one rule produces another rule, and the
130 rightmost portion of the latter produces the former.
132 I'm not 100% certain that this is as "strong" as the prefer/avoid
133 form (try to prove this, you probably can), but it's "what people
134 intend" most of the time.