gnu.kawa.lispexpr
Class LispReader

java.lang.Object
  java.io.Reader
      gnu.text.Lexer
          gnu.kawa.lispexpr.LispReader

All Implemented Interfaces:

java.io.Closeable, java.lang.Readable

Direct Known Subclasses:

BRLRead, Q2Read

public class LispReader
extends Lexer

A Lexer for reading S-expressions in generic Lisp-like syntax. This class may have outlived its usefulness: It's mostly just a wrapper around a LineBufferedReader plus a helper token-buffer. The functionality should be moved to ReadTable, though it is unclear what to do about the tokenBuffer.

Field Summary

protected boolean	finalColonIsKeyword True if "IDENTIFIER:" should be treated as a keyword.
protected boolean	initialColonIsKeyword True if ":IDENTIFIER" should be treated as a keyword.
static int	SCM_NUMBERS
protected boolean	seenEscapes If true, then tokenbuffer contains escaped characters.
static char	TOKEN_ESCAPE_CHAR

Fields inherited from class gnu.text.Lexer

interactive, nesting, port, tokenBuffer, tokenBufferLength

Fields inherited from class java.io.Reader

lock

Constructor Summary

LispReader(LineBufferedReader port)

LispReader(LineBufferedReader port, SourceMessages messages)

Method Summary

java.lang.Object	handleToken(int startPos, int endPos, ReadTable rtable) Classify and return a token in tokenBuffer from startPos to endPos.
static java.lang.Object	lookupUnit(java.lang.String name) Resolve a unit name, if possible.
protected java.lang.Object	makeNil()
protected java.lang.Object	makePair(java.lang.Object car, int line, int column)
java.lang.Object	makePair(java.lang.Object car, java.lang.Object cdr)
static java.lang.Object	parseNumber(char[] buffer, int start, int count, char exactness, int radix, int flags) Parse a number.
static java.lang.Object	readCharacter(LispReader reader)
java.lang.Object	readCommand() Read a "command" - a top-level expression or declaration.
int	readEscape() Reads a C-style String escape sequence.
int	readEscape(int c)
void	readNestedComment(char c1, char c2) Read a #|...|#-style comment (which may contain other nested comments).
static java.lang.Object	readNumberWithRadix(int previous, LispReader reader, int radix) Read a number from a LispReader
java.lang.Object	readObject()
java.lang.Object	readObject(int c)
static SimpleVector	readSimpleVector(LispReader reader, char kind)
static java.lang.Object	readSpecial(LispReader reader)
java.lang.Object	readValues(int ch, ReadTable rtable)
java.lang.Object	readValues(int ch, ReadTableEntry entry, ReadTable rtable) May return zero or multiple values.
protected java.lang.Object	returnSymbol(int startPos, int endPos, ReadTable rtable)
protected void	setCdr(java.lang.Object pair, java.lang.Object cdr)
protected boolean	validPostfixLookupStart(ReadTable rtable)

Methods inherited from class gnu.text.Lexer

checkErrors, checkNext, clearErrors, close, eofError, eofError, error, error, error, fatal, getColumnNumber, getErrors, getLineNumber, getMessages, getName, getPort, isInteractive, mark, peek, popNesting, pushNesting, read, read, readDigitsInBuffer, readOptionalExponent, reset, seenErrors, setInteractive, setMessages, skip_quick, skip, tokenBufferAppend, unread_quick, unread, unread

Methods inherited from class java.io.Reader

mark, markSupported, read, read, ready, skip

Methods inherited from class java.lang.Object

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

Field Detail

TOKEN_ESCAPE_CHAR

public static final char TOKEN_ESCAPE_CHAR

See Also:

Constant Field Values

seenEscapes

protected boolean seenEscapes

If true, then tokenbuffer contains escaped characters. These are prefixed (in the buffer) by TOKEN_ESCAPE_CHAR.

initialColonIsKeyword

protected boolean initialColonIsKeyword

True if ":IDENTIFIER" should be treated as a keyword.

finalColonIsKeyword

protected boolean finalColonIsKeyword

True if "IDENTIFIER:" should be treated as a keyword.

SCM_NUMBERS

public static final int SCM_NUMBERS

See Also:

Constant Field Values

Constructor Detail

LispReader

public LispReader(LineBufferedReader port)

LispReader

public LispReader(LineBufferedReader port,
                  SourceMessages messages)

Method Detail

lookupUnit

public static java.lang.Object lookupUnit(java.lang.String name)

Resolve a unit name, if possible. Returns null if the unit name is unknown.

readNestedComment

public final void readNestedComment(char c1,
                                    char c2)
                             throws java.io.IOException,
                                    SyntaxException

Read a #|...|#-style comment (which may contain other nested comments). Assumes the initial "#|" has already been read.

Throws:

java.io.IOException

SyntaxException

readValues

public java.lang.Object readValues(int ch,
                                   ReadTable rtable)
                            throws java.io.IOException,
                                   SyntaxException

Throws:

java.io.IOException

SyntaxException

readValues

public java.lang.Object readValues(int ch,
                                   ReadTableEntry entry,
                                   ReadTable rtable)
                            throws java.io.IOException,
                                   SyntaxException

May return zero or multiple values.

Throws:

java.io.IOException

SyntaxException

readObject

public java.lang.Object readObject()
                            throws java.io.IOException,
                                   SyntaxException

Throws:

java.io.IOException

SyntaxException

validPostfixLookupStart

protected boolean validPostfixLookupStart(ReadTable rtable)
                                   throws java.io.IOException

Throws:

java.io.IOException

parseNumber

public static java.lang.Object parseNumber(char[] buffer,
                                           int start,
                                           int count,
                                           char exactness,
                                           int radix,
                                           int flags)

Parse a number.

Parameters:

buffer - contains the characters of the number

start - startinging index of the number in the buffer

count - number of characters in buffer to use

exactness - either 'i' or 'I' force an inexact result, either 'e' or 'E' force an exact result, '\0' yields an inact or inexact depending on the form of the literal, while ' ' is like '\0' but does not allow more exactness specifiers.

radix - the number base to use or 0 if unspecified

Returns:

the number if a valid number; null or a String-valued error message if if there was some error parsing the number.

returnSymbol

protected java.lang.Object returnSymbol(int startPos,
                                        int endPos,
                                        ReadTable rtable)

handleToken

public java.lang.Object handleToken(int startPos,
                                    int endPos,
                                    ReadTable rtable)

Classify and return a token in tokenBuffer from startPos to endPos.

readEscape

public int readEscape()
               throws java.io.IOException,
                      SyntaxException

Reads a C-style String escape sequence. Assume '\\' has already been read. Return the converted character, or -1 on EOF, or -2 to ignore.

Throws:

java.io.IOException

SyntaxException

readEscape

public final int readEscape(int c)
                     throws java.io.IOException,
                            SyntaxException

Throws:

java.io.IOException

SyntaxException

readObject

public final java.lang.Object readObject(int c)
                                  throws java.io.IOException,
                                         SyntaxException

Throws:

java.io.IOException

SyntaxException

readCommand

public java.lang.Object readCommand()
                             throws java.io.IOException,
                                    SyntaxException

Read a "command" - a top-level expression or declaration. Return Sequence.eofValue of end of file.

Throws:

java.io.IOException

SyntaxException

makeNil

protected java.lang.Object makeNil()

makePair

protected java.lang.Object makePair(java.lang.Object car,
                                    int line,
                                    int column)

makePair

public java.lang.Object makePair(java.lang.Object car,
                                 java.lang.Object cdr)

setCdr

protected void setCdr(java.lang.Object pair,
                      java.lang.Object cdr)

readNumberWithRadix

public static java.lang.Object readNumberWithRadix(int previous,
                                                   LispReader reader,
                                                   int radix)
                                            throws java.io.IOException,
                                                   SyntaxException

Read a number from a LispReader

Parameters:

previous - number of characters already pushed on tokenBuffer

reader - LispReader to read from

radix - base to use or -1 if unspecified

Throws:

java.io.IOException

SyntaxException

readCharacter

public static java.lang.Object readCharacter(LispReader reader)
                                      throws java.io.IOException,
                                             SyntaxException

Throws:

java.io.IOException

SyntaxException

readSpecial

public static java.lang.Object readSpecial(LispReader reader)
                                    throws java.io.IOException,
                                           SyntaxException

Throws:

java.io.IOException

SyntaxException

readSimpleVector

public static SimpleVector readSimpleVector(LispReader reader,
                                            char kind)
                                     throws java.io.IOException,
                                            SyntaxException

Throws:

java.io.IOException

SyntaxException