Package org.apache.fontbox.type1

Class Type1Lexer

java.lang.Object

org.apache.fontbox.type1.Type1Lexer

class Type1Lexer
extends Object

Lexer for the ASCII portions of an Adobe Type 1 font.

See Also:

• The PostScript language, of which Type 1 fonts are a subset, has a somewhat awkward lexical structure. It is neither regular nor context-free, and the execution of the program can modify the the behaviour of the lexer/parser. Nevertheless, this class represents an attempt to artificially separate the PostScript parsing process into separate lexing and parsing phases in order to reduce the complexity of the parsing phase.
• "PostScript Language Reference 3rd ed, Adobe Systems (1999)"

Field Summary

Fields

Modifier and Type	Field	Description
private Token	aheadToken
private final ByteBuffer	buffer
private static final org.apache.commons.logging.Log	LOG	Log instance.
private int	openParens

Constructor Summary

Constructors

Constructor	Description
Type1Lexer(byte[] bytes)	Constructs a new Type1Lexer given a header-less .pfb segment.

Method Summary

Modifier and Type	Method	Description
private char	getChar()	Reads an ASCII char from the buffer.
Token	nextToken()	Returns the next token and consumes it.
boolean	peekKind(Token.Kind kind)	Checks if the kind of the next token equals the given one without consuming it.
Token	peekToken()	Returns the next token without consuming it.
private Token	readCharString(int length)	Reads a binary CharString.
private String	readComment()	Reads a line comment.
private String	readRegular()	Reads a sequence of regular characters, i.e.
private Token	readString()	Reads a (string).
private Token	readToken(Token prevToken)	Reads a single token.
private Token	tryReadNumber()	Reads a number or returns null.

Methods inherited from class java.lang.Object

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

Field Details

LOG

private static final org.apache.commons.logging.Log LOG

Log instance.

buffer

private final ByteBuffer buffer

aheadToken

private Token aheadToken

openParens

private int openParens

Constructor Details

Type1Lexer

Type1Lexer(byte[] bytes)
    throws IOException

Constructs a new Type1Lexer given a header-less .pfb segment.

Parameters:

bytes - Header-less .pfb segment

Throws:

IOException

Method Details

nextToken

public Token nextToken()
                throws IOException

Returns the next token and consumes it.

Returns:

The next token.

Throws:

IOException

peekToken

public Token peekToken()

Returns the next token without consuming it.

Returns:

The next token

peekKind

public boolean peekKind(Token.Kind kind)

Checks if the kind of the next token equals the given one without consuming it.

Returns:

true if the kind of the next token equals the given one

getChar

private char getChar()
              throws IOException

Reads an ASCII char from the buffer.

Throws:

IOException

readToken

private Token readToken(Token prevToken)
                 throws IOException

Reads a single token.

Parameters:

prevToken - the previous token

Throws:

IOException

tryReadNumber

private Token tryReadNumber()
                     throws IOException

Reads a number or returns null.

Throws:

IOException

readRegular

private String readRegular()
                    throws IOException

Reads a sequence of regular characters, i.e. not delimiters or whitespace

Throws:

IOException

readComment

private String readComment()
                    throws IOException

Reads a line comment.

Throws:

IOException

readString

private Token readString()
                  throws IOException

Reads a (string).

Throws:

IOException

readCharString

private Token readCharString(int length)
                      throws IOException

Reads a binary CharString.

Throws:

IOException