com.scriptbasic.lexer.elements

Class Decimal

java.lang.Object

com.scriptbasic.lexer.elements.AbstractElementAnalyzer

com.scriptbasic.lexer.elements.Decimal

All Implemented Interfaces:

LexicalElementAnalyzer

public class Decimal
extends AbstractElementAnalyzer

Constructor Summary

Constructors

Constructor and Description
Decimal()

Method Summary

Methods

Modifier and Type	Method and Description
LexicalElement	read() Read a decimal number from the input.

Methods inherited from class com.scriptbasic.lexer.elements.AbstractElementAnalyzer

getReader, setReader

Methods inherited from class java.lang.Object

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

Constructor Detail

Decimal

public Decimal()

Method Detail

read

public LexicalElement read()
                    throws LexicalException

Read a decimal number from the input. The next character following the number is left in the input stream to be available for the next getReader().get().

A decimal number does NOT have + or - sign, because that would cause trouble parsing expressions. It contains digits, optionally decimal point and exponent part following 'e' or 'E'.

Some languages allow formats like 1. or .12. This parser does not allow such unreadable format. If there is a decimal point then there has to be a digit on each side.

The returned lexeme will be double if there is decimal point or exponent part or both, even if the resulting value could be presented as long. Thus 1.12E2 is a double number and not a long containing 112.

Specified by:

read in interface LexicalElementAnalyzer

Specified by:

read in class AbstractElementAnalyzer

Returns:

the lexical element containing the long or double value

Throws:

LexicalException