xtc.parser
Class Resolver

java.lang.Object
  xtc.tree.Visitor
      xtc.parser.Resolver

public class Resolver
extends Visitor

Visitor to resolve grammar module dependencies.

Note that this visitor marks text-only productions as such. It also detects left recursions and marks direct left recursions. Furthermore, it sets a grammar's Properties.GENERIC and Properties.RECURSIVE properties as appropriate.

Version:

$Revision: 1.128 $

Author:

Robert Grimm

Field Summary

protected Analyzer	analyzer The analyzer utility.
protected AST	ast The type operations.
protected java.util.Map<NonTerminal,NonTerminal>	badNTs The identity hash map of erroneous nonterminals.
protected boolean	hasState The flag for whether the current module has a stateful attribute.
protected boolean	isMofunctor The flag for whether the current module is a mofunctor.
protected boolean	isPredicate Flag for whether the current expression is a predicate.
protected int	phase The current checking phase.
protected Runtime	runtime The runtime.
protected java.util.Set<SequenceName>	sequenceNames The set of sequence names for the current production.

Constructor Summary

Resolver(Runtime runtime, Analyzer analyzer, AST ast)
Create a new resolver.

Method Summary

protected void	apply(AlternativeAddition p1, FullProduction p2) Apply the specified alternative addition to the specified full production.
protected void	apply(AlternativeRemoval p1, FullProduction p2) Apply the specified alternative removal to the specified full production.
protected void	apply(ProductionOverride p1, FullProduction p2) Apply the specified production override to the specified full production.
protected void	applyModifications(Grammar g) Apply any module modifications.
protected java.util.List<Attribute>	check(Grammar g) Perform basic checking for the specified grammar.
protected void	checkExplicit(Grammar g) Check that explicit productions do not match the empty input.
protected void	checkRecursions(Grammar g) Check for left-recursive productions.
protected void	checkRepetitions(Grammar g) Check repetitions for elements that accept the empty input.
protected Module	combine(Grammar g, java.util.List<Attribute> attributes) Combine the modules in the specified grammar.
protected void	internTypes(Grammar g) Intern the grammar's types.
protected Grammar	load(Module m) Load all dependent modules.
protected Module	load(java.lang.String name) Load the module with the specified name.
protected void	rename(Module module, ModuleMap renaming) Rename the specified module.
protected void	signature(Module m) Print the specified module's signature.
protected Production	strip(Production p) Strip the specified production's ordered choice.
void	visit(Action a) Analyze the specified action.
void	visit(Binding b) Analyze the specified binding.
void	visit(CharClass c) Analyze the specified character class.
void	visit(InternalElement e) Analyze the specified internal element.
java.lang.Object	visit(Module m) Visit the specified module.
void	visit(NodeMarker m) Analyze the specified node marker.
void	visit(NonTerminal nt) Analyze the specified nonterminal.
void	visit(NullLiteral l) Analyze the specified null literal.
void	visit(Option o) Analyze the specified option.
void	visit(OrderedChoice c) Analyze the specified ordered choice.
void	visit(ParserAction pa) Analyze the specified parser action.
void	visit(Predicate p) Analyze the specified predicate.
void	visit(Production p) Analyze the specified production.
void	visit(Repetition r) Analyze the specified repetition.
void	visit(SemanticPredicate p) Analyze the specified semantic predicate.
void	visit(Sequence s) Analyze the specified sequence.
void	visit(StringLiteral l) Analyze the specified string literal.
void	visit(StringMatch m) Analyze the specified string match.
void	visit(Terminal t) Analyze the specified terminal.
void	visit(VoidedElement v) Analyze the specified voided element.

Methods inherited from class xtc.tree.Visitor

dispatch, equals, hashCode, iterate, map, mapInPlace, unableToVisit, visit

Methods inherited from class java.lang.Object

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

Field Detail

runtime

protected final Runtime runtime

The runtime.

analyzer

protected final Analyzer analyzer

The analyzer utility.

ast

protected final AST ast

The type operations.

phase

protected int phase

The current checking phase.

badNTs

protected java.util.Map<NonTerminal,NonTerminal> badNTs

The identity hash map of erroneous nonterminals.

hasState

protected boolean hasState

The flag for whether the current module has a stateful attribute.

isMofunctor

protected boolean isMofunctor

The flag for whether the current module is a mofunctor.

isPredicate

protected boolean isPredicate

Flag for whether the current expression is a predicate.

sequenceNames

protected java.util.Set<SequenceName> sequenceNames

The set of sequence names for the current production.

Constructor Detail

Resolver

public Resolver(Runtime runtime,
                Analyzer analyzer,
                AST ast)

Create a new resolver.

Parameters:

runtime - The runtime.

analyzer - The analyzer utility.

ast - The type operations.

Method Detail

signature

protected void signature(Module m)

Print the specified module's signature.

Parameters:

m - The module.

load

protected Module load(java.lang.String name)
               throws java.io.IOException,
                      ParseException

Load the module with the specified name.

Parameters:

name - The name.

Returns:

The corresponding grammar module.

Throws:

IllegalArgmentException - Signals that the file is too large.

java.io.FileNotFoundException - Signals that the file does not exist.

java.io.IOException - Signals an exceptional condition while accessing the file.

ParseException - Signals a parse error.

rename

protected void rename(Module module,
                      ModuleMap renaming)

Rename the specified module. This method renames all module names in the specified module, including the module's name, the module's dependencies, and each production's qualified name (if it is not null).

Parameters:

module - The module.

renaming - The renaming.

strip

protected Production strip(Production p)

Strip the specified production's ordered choice.

Parameters:

p - The production to strip.

Returns:

The specified production.

See Also:

Analyzer.stripChoices(xtc.parser.OrderedChoice)

apply

protected void apply(AlternativeAddition p1,
                     FullProduction p2)

Apply the specified alternative addition to the specified full production.

Parameters:

p1 - The alternative addition.

p2 - The full production.

apply

protected void apply(AlternativeRemoval p1,
                     FullProduction p2)

Apply the specified alternative removal to the specified full production.

Parameters:

p1 - The alternative removal.

p2 - The full production.

apply

protected void apply(ProductionOverride p1,
                     FullProduction p2)

Apply the specified production override to the specified full production.

Parameters:

p1 - The production override.

p2 - The full production.

load

protected Grammar load(Module m)

Load all dependent modules. This method loads the transitive closure of all dependent modules for the specified top-level module and returns the closure as a list, with the specified module being the first list element. It checks that the specified top-level module is not parameterized, that the parameters of parameterized modules are well-formed, that arguments match parameters when instantiating parameterized modules, that different instantiations are consistent with each other, that a module does not have more than one modifies clause, and that module modifications do not result in circular dependencies. This method also reports any file access and parsing errors. Finally, this method fills in the auxiliary modification field for all loaded modules.

Parameters:

m - The module.

Returns:

The corresponding grammar or null in the case of errors.

check

protected java.util.List<Attribute> check(Grammar g)

Perform basic checking for the specified grammar. This method does all correctness checking besides checking the contents of partial productions and checking for left-recursive definitions. Note that this method initializes the analyzer with the specified grammar.

Parameters:

g - The grammar.

Returns:

The list of global attributes, if any.

applyModifications

protected void applyModifications(Grammar g)

Apply any module modifications. This method applies all module modifications appearing in the specified grammar. It also removes unused modules from the grammar. This method assumes that all module dependencies have been successfully resolved, i.e., the specified grammar contains all module dependencies. This method also assumes that each module modification's modification field has been correctly initialized.

Parameters:

g - The grammar.

internTypes

protected void internTypes(Grammar g)

Intern the grammar's types. This method assumes that all module modifications have been applied.

Parameters:

g - The grammar.

checkRecursions

protected void checkRecursions(Grammar g)

Check for left-recursive productions. This method assumes that all module modifications have been applied.

Parameters:

g - The grammar.

checkRepetitions

protected void checkRepetitions(Grammar g)

Check repetitions for elements that accept the empty input. This method assumes that all module modifications have been applied.

Parameters:

g - The grammar.

checkExplicit

protected void checkExplicit(Grammar g)

Check that explicit productions do not match the empty input.

Parameters:

g - The grammar.

combine

protected Module combine(Grammar g,
                         java.util.List<Attribute> attributes)

Combine the modules in the specified grammar. This method combines the modules in the grammar by modifying the grammar's top-level module and then returns that module.

Parameters:

g - The grammar.

attributes - The list of global attributes.

Returns:

The grammar as a single module.

visit

public java.lang.Object visit(Module m)

Visit the specified module.

Parameters:

m - The module to resolve.

Returns:

A single, self-contained grammar module or null on an error condition.

visit

public void visit(Production p)

Analyze the specified production.

visit

public void visit(OrderedChoice c)

Analyze the specified ordered choice.

visit

public void visit(Repetition r)

Analyze the specified repetition.

visit

public void visit(Option o)

Analyze the specified option.

visit

public void visit(Sequence s)

Analyze the specified sequence.

visit

public void visit(Predicate p)

Analyze the specified predicate.

visit

public void visit(SemanticPredicate p)

Analyze the specified semantic predicate.

visit

public void visit(VoidedElement v)

Analyze the specified voided element.

visit

public void visit(Binding b)

Analyze the specified binding.

visit

public void visit(StringMatch m)

Analyze the specified string match.

visit

public void visit(NonTerminal nt)

Analyze the specified nonterminal.

visit

public void visit(Terminal t)

Analyze the specified terminal.

visit

public void visit(StringLiteral l)

Analyze the specified string literal.

visit

public void visit(CharClass c)

Analyze the specified character class.

visit

public void visit(NullLiteral l)

Analyze the specified null literal.

visit

public void visit(NodeMarker m)

Analyze the specified node marker.

visit

public void visit(Action a)

Analyze the specified action.

visit

public void visit(ParserAction pa)

Analyze the specified parser action.

visit

public void visit(InternalElement e)

Analyze the specified internal element.