Skip to content

Latest commit

 

History

History
115 lines (101 loc) · 5.54 KB

TODO.md

File metadata and controls

115 lines (101 loc) · 5.54 KB
Raw

TODO

Next task

  • Try remove beforeIns.
  • Try remove all LRJ syntax, build LRJ structure from state machine instead.

Test Cases

  • Code Coverage
    • Compiler
      • TODO(s) in RewriteRules_GenerateAffectedLRIClausesSubgroup.
      • FixPrefixMergeClauses in if (ruleSymbol->isPartial).
    • Runtime
      • TODO(s) in CalculateObjectFirstInstruction and InjectFirstInstruction.
      • TraceManager::TryMergeSurvivingTraces in // if trace is a merge trace.
      • TraceManager::BuildStepTree in which are not covered.
      • TraceManager::AddTraceToCollection in else if (collection == &Trace::predecessors)
  • Make a test case to test prefix_merge generates left_recursion_inject_multiple.
  • Create ambiguity test case caused by only one clause with alternative syntax.
  • Test when an object get LriFetch to multiple branches following a ReopenObject.
  • Deny X ::= Y LRI ... when X is or a prefix of Y.
  • Windows and Linux test output inconsistency on
    • the order of ambiguous candidates.
    • \r\n or \n serialized into <![CDATA[]]>.

Features to Add

  • Extensible tokens, for example, recognize R"[^\s(]\( and invoke a callback function to determine the end of the string.
    • Offer two options: using (rich regex | C++) to search for complete token.
  • AST file groups.
    • An AST file only sees:
      • Types defined in this file.
      • @public types defined in the same file group.
      • @extern types defined in different depended file groups as field type only.
    • C++ codegen are created per groups.
      • Only AST classes #include depended files groups, visitors do not.
      • When a visitor need to call types in different file groups, leave it abstract.
  • Multiple LRI following one Target
  • Generate multiple level of LRI from prefix_merge
    • Remove PrefixExtractionAffectedRuleReferencedAnother
    • Currently it generates an error if 3 levels are required
    • Allow one prefix followed by multiple continuations
      • Optional applies to all continuations as a whole

Issues (BuiltIn-Cpp)

  • ::a::b::c::*
    • Ambiguity
    • It should be invalid, because ::a::b::c are always parsed as one QualifiedName, instead of being ::a(::b::c::*) and ::a::b(::c::*)
    • Refer to Priority in left recursive transition
  • Compiler crashes:
    • _DeclOrExpr ::= !_BExpr ::= {_DeclaratorKeyword:keywords} _TypeBeforeDeclarator:type _DeclaratorRequiredName:declarator as DeclaratorType ;
    • workingSwitchValues is nullptr in ExpandClauseVisitor::FixRuleName

Issues (Glr)

  • When XToResolve is in another XToResolve, flatten them.
  • TODO in CalculateRuleAndClauseTypes.
  • TODO in ValidateDirectPrefixMergeRuleVisitor.
  • Optimize CalculateFirstSet_IndirectStartRules using partial ordering.
  • TODO in SyntaxSymbolManager::EliminateSingleRulePrefix.
    • Deny A ::= !B ::= B as Something ::= ...;.
  • TODO in CalculateObjectLastInstruction
  • TODO in CheckAmbiguityResolution
  • Print correct codeRange for:
    • ParserErrorType::RuleIsIndirectlyLeftRecursive
    • ParserErrorType::LeftRecursiveClauseInsidePushCondition
    • ParserErrorType::LeftRecursiveClauseInsideTestCondition
  • X ::= ([a] | [b]) c fails because multiple optional syntax create multiple epsilon transition between the same pair of states.
    • Possible solution: if multiple combinations of consecutive epsilon transitions makes an epsilon transition between two states, treat them as one single epsilon transition.
      • Merge conditions in these epsilon transitions properly.
    • Or one more phase before generationg automaton for optimization to merge states and edges.
  • Optimize CrossReferencedNFA to merge prefix (two states can be merged if their InEdges are identical, FromState in InEdges are replaced by merged states).
  • JsonEscapeString JsonUnescapeString handle surrogate pairs correctly.
  • Review all comments.

Experiments

  • Add union type and remove TypeOrExprOrOthers in C++.
    • Consider what does @ambiguous union mean.
  • Try to see if it is possible to
    • Remove PushReturnStack last argument.
    • Remove ReturnDesc::ruleType.
    • Move ReturnRuleType from automaton to symbol.
    • Share traces in different branches.
      • From a given state and a few tokens, the trace graph could be copied directly if:
        • none of state.returnStacks is reduced
        • competitions created before the first token are not attended
        • completitions created after the first token are closed
      • Do not copy, share it.
  • Serializing
    • Escaping and Unescaping pairs (instead of only unescaping)
    • Calculate ambiguous ToString cases
    • Generate ToString algorithm
  • Generate LL parser if possible (print error if failed but forced to do)
  • Generate SLR parser if possible (print error if failed but forced to do)
  • Document the algorithm in a markdown file

Work Items (enhancement)

  • Switching lexical analyzer during parsing.
    • Refactor some properties in LexerSymbolManager into LexerFile with a name.
  • Printing AST classes that created from a memory pool.
  • All token property X becomes X_, paired with a string property X to access the text value in X_.
  • New priority syntax
    • Priority in alternative syntax, but all branches must not consume empty input series (add compile error)
    • Priority in left recursive transition (which clause starts this competition?)
    • Priority in loop
  • Custom error in syntax.
  • Error recovering.
  • Escaping and unescaping functions
    • Offer two options: experiment
    • Map positions between escaped and unescaped text
  • Error if any condition is constantly evaluated to true or false