Package org.nineml.coffeegrinder.parser

Class SourceGrammar

java.lang.Object
org.nineml.coffeegrinder.parser.Grammar
org.nineml.coffeegrinder.parser.SourceGrammar
public class SourceGrammar extends Grammar
A grammar for the parser.

A grammar is a list of rules. Each rule defines a non-terminal symbol as a sequence of zero or more symbols (terminals or nonterminals).

A grammar can be used to create a parser. The parser will (successfully) parse inputs that match the rules in the grammar.

  • Field Details

  • Constructor Details

    • SourceGrammar

      public SourceGrammar()
      Create a new grammar with default options.

    • SourceGrammar

      public SourceGrammar(ParserOptions options)
      Create a new grammar with a specific set of options.
      Parameters:
      options - The options.
      Throws:
      NullPointerException - if options is null.

    • SourceGrammar

      public SourceGrammar(SourceGrammar current)
      Create a new grammar from an existing grammar.
      Parameters:
      current - the grammar to copy

  • Method Details

    • getNonterminal

      public NonterminalSymbol getNonterminal(String name)
      Return the nonterminal symbol identified by name.

      Nonterminal symbols are uniquely identified by their name.

      Any string can be used as a name.

      Parameters:
      name - The name of this symbol.
      Returns:
      The nonterminal for the name specified.
      Throws:
      NullPointerException - if the name is null.

    • getNonterminal

      public NonterminalSymbol getNonterminal(String name, ParserAttribute attribute)
      Return the nonterminal symbol identified by name.

      Nonterminal symbols are uniquely identified by their name.

      Any string can be used as a name.

      Parameters:
      name - The name of this symbol.
      attribute - an attribute.
      Returns:
      The nonterminal for the name specified.
      Throws:
      NullPointerException - if the name is null or the attribute is null.

    • getNonterminal

      public NonterminalSymbol getNonterminal(String name, List<ParserAttribute> attributes)
      Return the nonterminal symbol identified by name.

      Nonterminal symbols are uniquely identified by their name.

      Any string can be used as a name.

      Parameters:
      name - The name of this symbol.
      attributes - attributes to associate with this symbol, may be null
      Returns:
      The nonterminal for the name specified.
      Throws:
      NullPointerException - if the name is null.

    • addRule

      public void addRule(Rule rule)
      Add a rule to the grammar.

      Multiple rules can exist for the same NonterminalSymbol. There should be at least one rule for every nonterminal symbol that occurs on the "right hand side" of a rule. A symbol that is undefined but unreachable from the specified start symbol when parsing, isn't forbidden by CoffeeGrinder, but it is by CoffeeFilter.

      Once added, a rule can never be removed.

      Parameters:
      rule - The rule to add
      Throws:
      GrammarException - if any nonterminal in the rule is not from this grammar, or if the grammar is closed

    • addRule

      public void addRule(NonterminalSymbol nonterminal, Symbol... rhs)
      Add a rule to the grammar.

      This is a convenience method that will construct the Rule for you.

      Multiple rules can exist for the same NonterminalSymbol. There must be at least one rule for every nonterminal symbol that occurs on the "right hand side" of a rule.

      Parameters:
      nonterminal - The nonterminal symbol defined by this rule.
      rhs - The list of symbols that define it
      Throws:
      GrammarException - if any nonterminal in the rule is not from this grammar or if the grammar is closed

    • addRule

      public void addRule(NonterminalSymbol nonterminal, List<Symbol> rhs)
      Add a rule to the grammar.

      This is a convenience method that will construct the Rule for you.

      Multiple rules can exist for the same NonterminalSymbol. There must be at least one rule for every nonterminal symbol that occurs on the "right hand side" of a rule.

      Parameters:
      nonterminal - The nonterminal symbol defined by this rule.
      rhs - The list of symbols that define it.
      Throws:
      GrammarException - if any nonterminal in the rule is not from this grammar or if the grammar is closed

    • isNullable

      public boolean isNullable(Symbol symbol)
      Description copied from class: Grammar
      Is the symbol nullable?

      A TerminalSymbol is never nullable.

      For a ParserGrammar, the answer is definitive. For an SourceGrammar, a symbol that isn't currently nullable could become nullable by the addition of more rules.

      Specified by:
      isNullable in class Grammar
      Parameters:
      symbol - The symbol.
      Returns:
      true if the symbol is nullable

    • getParser

      public GearleyParser getParser(ParserOptions options, String seed)

    • getCompiledGrammar

      public ParserGrammar getCompiledGrammar(NonterminalSymbol seed)

    • getCompiledGrammar

      public ParserGrammar getCompiledGrammar(ParserType parserType, NonterminalSymbol seed)

    • getParser

      public GearleyParser getParser(ParserOptions options, NonterminalSymbol seed)
      Get a parser for this grammar.

      Returns a parser that will parse an input against the rules that define this grammar.

      Parameters:
      options - the options for this parser.
      seed - The NonterminalSymbol that your input is expected to match.
      Returns:
      the parser

    • resolveDuplicates

      public SourceGrammar resolveDuplicates()
      Resolve duplicate symbols in the grammar.

      This method may return a different SourceGrammar. In this new grammar, all of the unique nonterminals will have unique names. (That is, if a nonterminal A occurs twice in the grammar with different parser attributes, it will have two different names in the resolved grammar.)

      This method is public only so that it is possible to know what all of the nonterminals in the parse grammar will be.

      Returns:
      a grammar with duplicates resolved

    • getParserOptions

      public ParserOptions getParserOptions()
      Gets the parser options.
      Returns:
      the current options.

    • getHygieneReport

      public HygieneReport getHygieneReport(NonterminalSymbol seed)
      Get a hygiene report for this grammar.
      Parameters:
      seed - The seed rule for hygiene checking.
      Returns:
      the report.

    • contains

      public boolean contains(Rule candidate)
      Does this grammar contain an equivalent rule?

      Two rules are equivalent if they have the same symbol, the same list of right-hand-side symbols, and if the attributes and optionality of every symbol on the right-hand-side are the same in both rules.

      Parameters:
      candidate - the candidate rule
      Returns:
      true if the grammar contains an equivalent rule

    • setMetadataProperty

      public void setMetadataProperty(String name, String value)
      Sets a metadata property.

      Metadata properties exist solely for annotations by an application. They have no bearing on the function of the grammar.

      Parameters:
      name - the name of the property
      value - the value of the property, or null to remove a property
      Throws:
      NullPointerException - if the name is null