1 _____________________________________________________________________________
4 - Sequence shouldn't be an Element
5 - Should Tree<T> really be type-parameterized?
7 - More topology untangling
8 - needs/hates/follow API ugliness
10 - do Forest/Tree still need a Region?
11 - reconsider the degree of genericization
12 - GraphViz stuff pollutes the API...
13 - Forest needs a "manual access" API
14 - the unwrap bit in Forest makes it really hard to expose an API for forests
16 - evil problems with (x y? z /ws)
17 - ParseFailed, GSS, Walk, Parser, Sequence, Forest
21 - grammar highlighting?
22 - comment indentation vs block indentation?
24 - recursive { { foo } }
26 ______________________________________________________________________________
29 - finalize metagrammar and rdp-op's
34 - RFC2822 (email message/headers)
35 - clean up the whole Walk situation (?)
38 ______________________________________________________________________________
41 - serialization of parse tables
43 - "ambiguity modulo dropped fragments"?
44 - can this be checked statically?
45 - eliminated statically?
47 - substring parsing for better error messages
50 - "Regular Right Part" grammars (NP Chapman, etc)
51 - Attribute unification
53 - inference of rejections for literals
54 - "prefer whitespace higher up" (?)
56 - Labeled edges on trees (associate a label with each slot in the
57 child array in Forest.Body? might make equality tough) --
58 equivalent to Feature Structures. Colon-labeling.
60 ______________________________________________________________________________
63 - Partly-Linear-PATR? (O(n^6) unification grammar)
65 - Implement a k-token peek buffer (for each state, see if it "dead
66 ends" during the next k Phases based solely on state -- ignoring
69 - Arrange for the SPPF corresponding to dropped subtrees to never be
70 generated (or merged, etc)
72 - Is there any way we can avoid creating a GSS.Node instance for
73 nodes which are transient in the sense that they have only one
76 - Re-read Rekers, particularly the stuff on optimal sharing
78 - Isolate the Element objects from Parse.Table/GSS so we can move
81 - consider allowing a Forest.Body to represent some other Tree whose
82 Body's should be [recursively] considered part of this Forest.
84 - perhaps not: right now we have a nice situation where
85 Forest.Ref instances become immutable once iterator()ed. This
86 also gives us a strong place to to culling with the certainty
87 that we won't throw out a Body which would later be salvaged
88 by some yet-to-be-added dependency.
90 - Figure out if there is a way to:
92 - allow unwrapping of children other than the very last one.
94 - fold repetitions into an array form in Forest, before
95 conversion to Tree. The major problem here is that multiple
96 tree-arrays are possible, all of different lengths. Worse,
97 even if they're all the same length, not all elements belong
98 in the same "possibility vector" as all others. You
99 essentially need a GSS to represent the array, which perhaps
100 is what the unfolded form was in the first place.
102 - Wikipedia grammar (needs to be both lexerless and boolean)
105 => Ordered Choice (";" operator)
107 - bring back in parse-table phase resolution of precedence (just
108 like associativity). This can be inferred from the use of ">"
109 when the rules are in one of these special forms:
120 where "_" is anything and "E" is the defining nonterminal.
121 Essentially what we're looking for is the situation where the
122 leftmost portion of one rule produces another rule, and the
123 rightmost portion of the latter produces the former.
125 I'm not 100% certain that this is as "strong" as the prefer/avoid
126 form (try to prove this, you probably can), but it's "what people
127 intend" most of the time.
129 - implement Johnstone's algorithm for "reduced, resolved LR
130 tables" to eliminate superfluous reductions on
133 ______________________________________________________________________________
136 - Rekers & Koorn note that GLR Substring Parsing can be used to do
137 really elegant and generalized "autocompletion".
140 ______________________________________________________________________________
143 - Incremental parse table construction
144 - "lazy GLR" and "lazy trees" -> language with first-class CF matching
145 - perhaps linear boolean grammars instead? (linear time, quad space)
146 - Forest parsing => chained parsers
147 - unification parsing, attributes, etc
149 - Take another stab at maximal-match? Nonterminal not-followed-by is
151 - Error recovery based on substring parsing