oops3
Class Parser

Object
  Parser

All Implemented Interfaces:

Serializable, Scanner.Lookup

public class Parser
extends Object
implements Scanner.Lookup, Serializable

represents literals, patterns, and rules of a grammar. The parser will be loaded using an ObjectInputStream.

Version:

3.5.0

See Also:

Serialized Form

Nested Class Summary

class	Parser.And represents a complete, unordered selection among two or more Nodes.
class	Parser.AndList represents a complete, unordered, delimited selection among two or more Nodes.
class	Parser.Binding<V> represents a binding (type and generic value) for a name.
class	Parser.Delimit represents an iterated collection of Nodes with delimiters.
class	Parser.Group base class for collections of Nodes.
class	Parser.Literal represents a literal input, not to be collected.
class	Parser.Node basic behavior for the grammar tree: an immutable List with lookahead.
class	Parser.Nonterminal represents a reference to a Rule.
class	Parser.Or represents an inclusive selection among two or more Nodes.
class	Parser.OrList represents an inclusive selection among two or more Nodes.
class	Parser.Pattern represents a binding (type and pattern string) for a Token name.
class	Parser.Permute base class for unordered selections among two or more Nodes.
class	Parser.PermutedList base class for unordered, delimited selections among two or more Nodes.
class	Parser.Repeat represents an iterated collection of Nodes.
class	Parser.Rule represents a binding (type and right-hand side node) for a Nonterminal name.
class	Parser.Sequence represents a sequence of Nodes.
class	Parser.Terminal base class for input symbols, i.e., Literal and Token.
class	Parser.Token represents a reference to a Pattern.
class	Parser.Type represents type information.
class	Parser.Xor represents an exclusive selection among two or more Nodes.

Field Summary

protected String	epilog prolog and epilog code.
protected Map<String,Parser.Literal>	literals collects Literal strings.
protected BitSet[]	lookaheads lookahead sets: Each list element denotes a set of symbols which is the lookahead for a Node.
protected Parser.Pattern[]	patterns one Pattern per Token name in order of definition.
protected String	prolog prolog and epilog code.
protected Parser.Rule[]	rules one Rule per Nonterminal name in order of definition.
protected int	start index of start symbol in rules.

Constructor Summary

protected

Parser() should only be created by ParserFactory and set up using package access.

Method Summary

int	getSymbol(String literal) lookup symbol value of Literal.
int	getToken(String token) lookup symbol value of Pattern.
protected static boolean	noType(Parser.Type type) true if there is a null or [vV]oid type.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

prolog

protected String prolog

prolog and epilog code.

epilog

protected String epilog

prolog and epilog code.

literals

protected Map<String,Parser.Literal> literals

collects Literal strings. These strings are unique and should take precedence over patterns in the scanner.

patterns

protected Parser.Pattern[] patterns

one Pattern per Token name in order of definition. There might be more for macros (untyped) and skips (void).

rules

protected Parser.Rule[] rules

one Rule per Nonterminal name in order of definition. The first one is the start symbol of the grammar.

start

protected int start

index of start symbol in rules.

lookaheads

protected BitSet[] lookaheads

lookahead sets: Each list element denotes a set of symbols which is the lookahead for a Node. Pattern contains a symbol value which the scanner must generate for a matching token. Literal contains a symbol value which the scanner must generate for the literal. Each Node contains an index into this list; the index also identifies the follow set in Follow. The list can be computed by Lookahead or read as a resource.

Constructor Detail

Parser

protected Parser()

should only be created by ParserFactory and set up using package access.

Method Detail

getSymbol

public int getSymbol(String literal)

lookup symbol value of Literal.

Specified by:

getSymbol in interface Scanner.Lookup

getToken

public int getToken(String token)

lookup symbol value of Pattern. Inefficient -- linear search.

Specified by:

getToken in interface Scanner.Lookup

noType

protected static boolean noType(Parser.Type type)

true if there is a null or [vV]oid type.