| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
FormalLanguage.CFG.Grammar.Types
Description
The data types that define a CFG.
- data Index = Index {
- _indexVar :: String
- _indexRange :: [String]
- _indexStep :: Int
- indexVar :: Lens' Index String
- indexStep :: Lens' Index Int
- indexRange :: Lens' Index [String]
- newtype SymbolName = SymbolName {}
- getSteName :: Iso' SymbolName String
- newtype Tape = Tape {}
- getTape :: Iso' Tape Int
- data SynTermEps
- name :: Traversal' SynTermEps SymbolName
- index :: Traversal' SynTermEps [Index]
- _Epsilon :: Prism' SynTermEps ()
- _Deletion :: Prism' SynTermEps ()
- _Term :: Prism' SynTermEps (SymbolName, [Index])
- _SynTerm :: Prism' SynTermEps (SymbolName, [Index])
- _SynVar :: Prism' SynTermEps (SymbolName, [Index])
- newtype Symbol = Symbol {
- _getSymbolList :: [SynTermEps]
- getSymbolList :: Iso' Symbol [SynTermEps]
- newtype AttributeFunction = Attr {}
- getAttr :: Iso' AttributeFunction String
- data Rule = Rule {}
- rhs :: Lens' Rule [Symbol]
- lhs :: Lens' Rule Symbol
- attr :: Lens' Rule [AttributeFunction]
- data DerivedGrammar
- isOutside :: DerivedGrammar -> Bool
- data Grammar = Grammar {}
- write :: Lens' Grammar Bool
- termvars :: Lens' Grammar (Map SymbolName SynTermEps)
- synvars :: Lens' Grammar (Map SymbolName SynTermEps)
- synterms :: Lens' Grammar (Map SymbolName SynTermEps)
- start :: Lens' Grammar Symbol
- rules :: Lens' Grammar (Set Rule)
- params :: Lens' Grammar (Map String Index)
- outside :: Lens' Grammar DerivedGrammar
- grammarName :: Lens' Grammar String
Documentation
Encode the index of the syntactic or terminal variable.
In case of grammar-based indexing, keep indexRange empty. The
indexStep keeps track of any +k / -k given in the production
rules.
We allow indexing terminals now, too. When glueing together terminals, one might want to be able to differentiate between terminals.
Constructors
| Index | |
Fields
| |
indexRange :: Lens' Index [String] Source
The tape, a terminal operates on. Terminals on different tapes could
still have the same SymbolName but different type and input!
data SynTermEps Source
Symbols, potentially with an index or more than one.
Constructors
| SynVar | Syntactic variables. |
Fields
| |
| SynTerm | |
Fields
| |
| Term | Regular old terminal symbol -- reads stuff from the input. |
Fields
| |
| Deletion | This sym denotes the case, where we have an |
| Epsilon | Finally, a real epsilon. Again, these are somewhat regular terminal symbols, but it is important to be able to recognize these, when trying to create outside variants of our algorithms. |
Instances
index :: Traversal' SynTermEps [Index] Source
_Epsilon :: Prism' SynTermEps () Source
_Deletion :: Prism' SynTermEps () Source
_Term :: Prism' SynTermEps (SymbolName, [Index]) Source
_SynTerm :: Prism' SynTermEps (SymbolName, [Index]) Source
_SynVar :: Prism' SynTermEps (SymbolName, [Index]) Source
The length of the list encodes the dimension of the symbol. Forms a monoid over dimensional concatenation.
Constructors
| Symbol | |
Fields
| |
newtype AttributeFunction Source
The name of an attribute function
Production rules for at-most CFGs.
Constructors
| Rule | |
attr :: Lens' Rule [AttributeFunction] Source
data DerivedGrammar Source
Instances
isOutside :: DerivedGrammar -> Bool Source
Complete descrition of a grammar. In principle it would be enough to hold
_rules and the _start symbol name. We also store dimensionless names for
syntactiv variables, and terminals. This makes certain checks easier or
possible.
We store all single-tape symbol names dimensionless. This means that, for terminals, symbols with the same name have the same tape. This is slightly inconvenient for special applications (say Protein-DNA alignment) but one can easily rename terminals.
TODO better way to handle indexed symbols?
Constructors
| Grammar | |
Fields
| |