Package tech.ixor.calclox

Class Scanner

java.lang.Object

tech.ixor.calclox.Scanner

public class Scanner
extends Object

Converts CalcLox source text into the token stream consumed by Parser.

The scanner recognizes identifiers, reserved words, decimal numbers, strings, punctuation, and operators. Spaces, tabs, carriage returns, and // line comments are ignored. Line breaks are retained as token line metadata so later compilation and runtime errors can identify their source location.

A scanner instance is single-use. Call scanTokens() once for a given source.

Constructor Summary

Constructors

Constructor	Description
Scanner(String source)	Creates a scanner positioned at the beginning of the supplied source.

Method Summary

Modifier and Type	Method	Description
List<Token>	scanTokens()	Scans the complete source and appends a final EOF token.

Methods inherited from class java.lang.Object

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

Constructor Details

Scanner

public Scanner(String source)

Creates a scanner positioned at the beginning of the supplied source.

Parameters:

source - complete CalcLox source text

Throws:

NullPointerException - if source is null

Method Details

scanTokens

public List<Token> scanTokens()

Scans the complete source and appends a final EOF token. Number literals are represented as Double; string literal values omit their surrounding quotation marks.

Returns:

tokens in source order, including the terminating EOF token

Throws:

CalcLoxRunnerError - if the source contains an unknown character or an unterminated string