com.goldencode.ast

Class LexerDumpHelper

java.lang.Object

com.goldencode.ast.LexerDumpHelper

public class LexerDumpHelper
extends java.lang.Object

Provides a simple mechanism to run a given lexer on and to print the resulting stream of tokens. The output is a column formatted list with one line printed for each token.

The first column is formatted as "[" line number ":" column number "]".

The second column is the symbolic representation of the integer token type of that token. The third column is the actual text from the file that corresponds to that token.

Field Summary

Fields

Modifier and Type	Field and Description
private java.text.NumberFormat	cfmt Formats a column number padded on left with zeros.
private antlr.TokenStream	lexer An instance of the lexer object.
private java.text.NumberFormat	lfmt Formats a line number padded on left with zeros.
private int	maxSymSize Size in characters of the largest possible token type name.
private java.lang.String[]	names Maps token types (as indexes) to token names.
private java.io.PrintWriter	out Output destination.

Constructor Summary

Constructors

Constructor and Description
LexerDumpHelper(antlr.TokenStream lexer, java.lang.String[] names, java.io.PrintStream out) Constructs an instance of the test driver using a specific instance of the lexer.
LexerDumpHelper(antlr.TokenStream lexer, java.lang.String[] names, java.io.PrintWriter out) Constructs an instance of the test driver using a specific instance of the lexer.

Method Summary

Modifier and Type	Method and Description
private void	calcMaximumSymbolNameSize() Scans the list of token type names (text symbols that represent each integer token type) and calculates the width in characters of the largest one.
void	dump() Prints a report with one line per token in the token stream.
private void	printToken(antlr.CommonToken next) Prints a one line record for the token object passed as a parameter.

Methods inherited from class java.lang.Object

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

Field Detail

lfmt

private java.text.NumberFormat lfmt

Formats a line number padded on left with zeros.

cfmt

private java.text.NumberFormat cfmt

Formats a column number padded on left with zeros.

maxSymSize

private int maxSymSize

Size in characters of the largest possible token type name.

lexer

private antlr.TokenStream lexer

An instance of the lexer object.

names

private java.lang.String[] names

Maps token types (as indexes) to token names.

out

private java.io.PrintWriter out

Output destination.

Constructor Detail

LexerDumpHelper

public LexerDumpHelper(antlr.TokenStream lexer,
                       java.lang.String[] names,
                       java.io.PrintWriter out)

Constructs an instance of the test driver using a specific instance of the lexer. This will initialize our formatting objects to a known state.

Parameters:

lexer - Instance of the lexer to use for tokenizing the input file.

names - The array of token names indexed by token type.

out - Destination for output.

LexerDumpHelper

public LexerDumpHelper(antlr.TokenStream lexer,
                       java.lang.String[] names,
                       java.io.PrintStream out)

Constructs an instance of the test driver using a specific instance of the lexer. This will initialize our formatting objects to a known state.

Parameters:

lexer - Instance of the lexer to use for tokenizing the input file.

names - The array of token names indexed by token type.

out - Destination for output.

Method Detail

calcMaximumSymbolNameSize

private void calcMaximumSymbolNameSize()

Scans the list of token type names (text symbols that represent each integer token type) and calculates the width in characters of the largest one. This is saved as the column width in the output report.

dump

public void dump()
          throws antlr.TokenStreamException,
                 java.io.IOException

Prints a report with one line per token in the token stream.

Throws:

antlr.TokenStreamException - If an respective error occurs.

java.io.IOException - If an respective error occurs.

printToken

private void printToken(antlr.CommonToken next)
                 throws java.io.IOException

Prints a one line record for the token object passed as a parameter. The record is printed in a 3 column format as documented in the overview section.

Parameters:

next - The token to print.

Throws:

java.io.IOException - If an respective error occurs.