Grammar.LR.Lossless (IchorRuntime v0.5.0)

The LR shift-reduce loop for a lossless parse: the same moves as Grammar.LR's and Grammar.Native.LR's, building captures with Ichor.Syntax.Record.reduced/3, so the rules' records travel with them.

Table-driven on purpose, for both backends. The generated LR parser compiles every state into its own function, which calls the ordinary Grammar.LR.Stack.reduce/4 inline. A lossless variant of those would be a second copy of every state function. Instead, a parser generated with lossless: true embeds its table as data and hands it to this loop through action_fn/goto_fn -- the shape Grammar.GLR.Runtime already takes -- so the fast path's functions stay exactly as they are, and the lossless path pays for lookups rather than for code.

Summary

Functions

run(action_fn, goto_fn, productions, start_state, end_symbol, stream)

Runs the loop over stream from start_state. action_fn answers a state and a lookahead with the table's list of actions -- one, since an LR table has no conflicts -- and goto_fn a state and a nonterminal with the state to go to.

Functions

run(action_fn, goto_fn, productions, start_state, end_symbol, stream)

@spec run(
  (Grammar.LRTable.state_id(), atom() -> [Grammar.LRTable.action()]),
  (Grammar.LRTable.state_id(), atom() -> Grammar.LRTable.state_id() | nil),
  %{required(non_neg_integer()) => Grammar.LRTable.Production.t()},
  Grammar.LRTable.state_id(),
  atom(),
  tuple()
) ::
  {:ok, non_neg_integer(), Ichor.Capture.raw_captures()}
  | {:error, Ichor.Error.t()}