Class QueryPrologLexer

java.lang.Object
org.eclipse.rdf4j.query.parser.QueryPrologLexer
public class QueryPrologLexer extends Object
A simple lexer that tokenizes a syntactically legal input SPARQL query string on prolog items (prefixes, base declarations, IRIs, comments, and syntactical tokens such as keywords, opening and closing brackets, and hashes).

  • Field Details

  • Constructor Details

    • QueryPrologLexer

      public QueryPrologLexer()

  • Method Details

    • lex

      public static List<QueryPrologLexer.Token> lex(String input)
      Tokenizes a syntactically legal input SPARQL query on prolog elements. The last token in the returned list is of type QueryPrologLexer.TokenType.REST_OF_QUERY and contains the SPARQL query string minus the prolog.
      Parameters:
      input - a syntactically legal SPARQL query string
      Returns:
      a list with tokens for each prolog element. If the input string is syntactically legal SPARQL, the final returned token is guaranteed to be of type QueryPrologLexer.TokenType.REST_OF_QUERY and to contain the SPARQL query string minus the prolog. If the input string is not syntactically legal SPARQL, the method will still return normally but no guarantees about the returned list are made.

    • getRestOfQueryToken

      public static QueryPrologLexer.Token getRestOfQueryToken(String input)
      Tokenizes the input string on prolog elements and returns the final Token. If the input string is a syntactically legal SPARQL query, this Token will be of type QueryPrologLexer.TokenType.REST_OF_QUERY and contain the query string minus prolog.
      Parameters:
      input - a syntactically legal SPARQL string
      Returns:
      if the input is syntactically legal SPARQL, a Token containing the query string without prolog. If the input is not syntactically legal, the method will still exist normally, but no guarantees are made about the returned object.

    • readComment

      private static String readComment(String input, int index)
      Reads the first comment line from the input, and returns the comment line (including the line break character) without the leading "#".
      Parameters:
      input -
      index -
      Returns:

    • readPrefix

      private static String readPrefix(String input, int index)

    • readIRI

      private static String readIRI(String input, int index)