restructure

src/scanner.d

@@ -1,147 +0,0 @@
-import std.ascii;
-import std.conv;
-
-import token;
-import tokentype;
-import main : error, report;
-
-private bool isAlpha_(dchar c)    => c.isAlpha    || c == '_';
-private bool isAlphaNum_(dchar c) => c.isAlphaNum || c == '_';
-
-class Scanner {
-	private string source;
-	private Token[] tokens;
-	private uint start = 0;
-	private uint current = 0;
-	private uint line = 1;
-
-	this(string source){
-		this.source = source;
-	}
-	private bool isAtEnd(uint n = 0) const => current + n >= source.length;
-	private char advance() => source[current++];
-	private char peek(uint n = 0) const => isAtEnd(n) ? '\0' : source[current + n];
-	private char peekNext() const => peek(1);
-	private bool match(char expected){
-		if(peek() != expected)
-			return false;
-		current++;
-		return true;
-	}
-	private void addToken(TokenType type, TTokenValue literal = TTokenValue.nil(0)){
-		string text = source[start .. current];
-		tokens ~= new Token(type, text, literal, line);
-	}
-	Token[] scanTokens(){
-		while(!isAtEnd){
-			start = current;
-			scanToken();
-		}
-		addToken(TokenType.EOF);
-		return tokens;
-	}
-	private void stringLiteral(){
-		while(peek() != '"' && !isAtEnd){
-			if(peek() == '\n')
-				line++;
-			advance();
-		}
-		if(isAtEnd){
-			error(line, "Unterminated string.");
-			return;
-		}
-		advance();
-		string value = source[start + 1 .. current -1];
-		addToken(TokenType.STRING, TTokenValue.str(value));
-	}
-	private void number(){
-		while(peek().isDigit)
-			advance();
-		if(peek() == '.' && peekNext().isDigit){
-			advance(); // Eat the .
-			while(peek().isDigit)
-				advance();
-		}
-		addToken(TokenType.NUMBER, TTokenValue.dbl(source[start .. current].to!double));
-	}
-	private TokenType keywords(string word){
-		with(TokenType) switch(word){
-			case "and":    return AND;
-			case "class":  return CLASS;
-			case "else":   return ELSE;
-			case "false":  return FALSE;
-			case ":or":    return FOR;
-			case "fun":    return FUN;
-			case "if":     return IF;
-			case "nil":    return NIL;
-			case "or":     return OR;
-			case "print":  return PRINT;
-			case "return": return RETURN;
-			case "super":  return SUPER;
-			case "this":   return THIS;
-			case "true":   return TRUE;
-			case "var":    return VAR;
-			case "while":  return WHILE;
-			default:       return IDENTIFIER;
-		}
-	}
-	private void identifier(){
-		while(peek().isAlphaNum_)
-			advance();
-		addToken(keywords(source[start .. current]));
-	}
-	private void scanToken() {
-		char c = advance();
-		with(TokenType) switch(c){
-			case '(': addToken(LEFT_PAREN); break;
-			case ')': addToken(RIGHT_PAREN); break;
-			case '{': addToken(LEFT_BRACE); break;
-			case '}': addToken(RIGHT_BRACE); break;
-			case ',': addToken(COMMA); break;
-			case '.': addToken(DOT); break;
-			case '-': addToken(MINUS); break;
-			case '+': addToken(PLUS); break;
-			case ';': addToken(SEMICOLON); break;
-			case '*': addToken(STAR); break; 
-			case '!':
-				addToken(match('=') ? BANG_EQUAL : BANG);
-				break;
-			case '=':
-				addToken(match('=') ? EQUAL_EQUAL : EQUAL);
-				break;
-			case '<':
-				addToken(match('=') ? LESS_EQUAL : LESS);
-				break;
-			case '>':
-				addToken(match('=') ? GREATER_EQUAL : GREATER);
-				break;
-			case '/':
-				if(match('/')){
-					while(peek() != '\n' && !isAtEnd)
-						advance();
-				} else {
-					addToken(SLASH);
-				}
-				break;
-			case ' ', '\r', '\t':
-				break;
-			case '\n':
-				line++;
-				break;
-			case '"':
-				stringLiteral();
-				break;
-			case '0': .. case '9':
-				number();
-				break;
-			case 'a': .. case 'z':
-			case 'A': .. case 'Z':
-			case '_':
-				identifier();
-				break;
-			default:
-				error(line, "Unexpected character");
-		}
-	}
-}
-