Module com.maroontress.clione

Package com.maroontress.clione.impl

Class DefaultLexicalParser

java.lang.Object

com.maroontress.clione.impl.DefaultLexicalParser

All Implemented Interfaces:

LexicalParser, AutoCloseable

public final class DefaultLexicalParser
extends Object
implements LexicalParser

The default implementation of LexicalParser.

Constructor Summary

Constructors

Constructor	Description
DefaultLexicalParser(Reader reader, String filename, Collection<String> reservedWords)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
void	close()
Optional<SourceChar>	getEof()	Returns the character representing EOF.
String	getFilename()	Returns the filename.
SourceLocation	getLocation()	Returns the current location of the source file.
Set<String>	getReservedWords()	Returns the unmodifiable Set containing the reserved words that this parser uses.
Optional<Token>	next()	Returns the next token.

Methods inherited from class java.lang.Object

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

Constructor Details

DefaultLexicalParser

public DefaultLexicalParser(Reader reader,
 String filename,
 Collection<String> reservedWords)

Creates a new instance.

Parameters:

reader - The reader that provides the stream of the source file.

filename - The filename.

reservedWords - The collection that contains reserved keywords. Note that the constructor copies the collection, so changes to the collection do not affect this instance.

Method Details

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface LexicalParser

Throws:

IOException

getEof

public Optional<SourceChar> getEof()
                            throws IOException

Returns the character representing EOF.

Note that there is no need for this method in most cases. If you want to detect when the line concatenation (a backslash followed by a newline character) is immediately followed by EOF, you can do so as follows:

        void parse(LexicalParser parser) {
            for (;;) {
                var maybeToken = parser.next();
                if (maybeToken.isEmpty()) {
                    var maybeEof = parser.getEof();
                    assert(maybeEof.isPresent());
                    var eof = maybeEof.get();
                    assert(eof.isEof());
                    var list = eof.getChildren();
                    if (list.size() > 0) {
                        var m = "backslash-newline at end of file";
                        System.err.println(eof.getSpan() + ": warning: " + m);
                    }
                    break;
                }
                ...
            }
        }

Specified by:

getEof in interface LexicalParser

Returns:

The character representing EOF. Or Optional.empty() if this parser has not yet reached EOF.

Throws:

IOException - If an I/O error occurs.

getLocation

public SourceLocation getLocation()

Returns the current location of the source file.

Specified by:

getLocation in interface LexicalParser

Returns:

The current location.

getFilename

public String getFilename()

Returns the filename.

Specified by:

getFilename in interface LexicalParser

Returns:

The filename. Or null if no filename is specified.

next

public Optional<Token> next()
                     throws IOException

Returns the next token.

Specified by:

next in interface LexicalParser

Returns:

The next token. Or Optional.empty() if this parser reaches EOF.

Throws:

IOException - If an I/O error occurs.

getReservedWords

public Set<String> getReservedWords()

Returns the unmodifiable Set containing the reserved words that this parser uses.

Specified by:

getReservedWords in interface LexicalParser

Returns:

The unmodifiable Set containing the reserved words.