Data.Cfg.Analysis

Analysis of a context-free grammar

Documentation

data Analysis t nt

Analysis of a context-free grammar

Constructors

Analysis

Fields

• baseCfg :: FreeCfg t nt

  (a FreeCfg equivalent to) the source grammar

• augmentedCfg :: FreeCfg (AugT t) (AugNT nt)

  the augmented grammar

• nullables :: Set (AugNT nt)

  the nonterminals in the grammar that can produce the empty string

• firstSet :: AugNT nt -> LookaheadSet t

  the first set of the nonterminal for the grammar

• firstsOfVs :: AugVs t nt -> LookaheadSet t

  the first set of a list of symbols

• followSet :: AugNT nt -> LookaheadSet t

  the follow set of the nonterminal for the grammar

• predictSet :: AugProduction t nt -> LookaheadSet t

  the predict set of the production

• isLL1 :: Bool

  True iff the grammar is LL(1)

• ll1Info :: AugNT nt -> Predictions t nt

  the productions for this nonterminal and the lookaheads that predict them

mkAnalysis :: forall cfg t nt. (Cfg cfg t nt, Ord nt, Ord t) => cfg t nt -> Analysis t nt

Analyzes a context-free grammar

type Prediction t nt = (LookaheadSet t, Set (AugProduction t nt))

A lookahead set with the productions it predicts

type Predictions t nt = Set (Prediction t nt)

A set of Predictions. The LookaheadSets of the Predictions will be pairwise disjoint.