semester05-compiler_construction/exercise02
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finished parts of the test

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quirinecker
2025-10-18 17:46:16 +02:00
parent ececfae877
commit b9174804cc
1 changed files with 335 additions and 74 deletions
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409
MicroJava Compiler/src/ssw/mj/impl/Scanner.java
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@@ -3,106 +3,367 @@ package ssw.mj.impl;
import ssw.mj.Errors; import ssw.mj.Errors;
import ssw.mj.scanner.Token; import ssw.mj.scanner.Token;
import java.io.IOException;
import java.io.Reader; import java.io.Reader;
import java.util.HashMap; import java.util.HashMap;
import java.util.Map; import java.util.Map;
import java.util.Optional;
import static ssw.mj.scanner.Token.Kind.none; import static ssw.mj.scanner.Token.Kind.*;
public class Scanner { public class Scanner {
// Scanner Skeleton - do not rename fields / methods ! // Scanner Skeleton - do not rename fields / methods !
private static final char EOF = (char) -1; private static final char EOF = (char) -1;
private static final char LF = '\n'; private static final char LF = '\n';
/** /**
* Input data to read from. * Input data to read from.
*/ */
private final Reader in; private final Reader in;
/** /**
* Lookahead character. (= next (unhandled) character in the input stream) * Lookahead character. (= next (unhandled) character in the input stream)
*/ */
private char ch; private char ch;
/** /**
* Current line in input stream. * Current line in input stream.
*/ */
private int line; private int line;
/** /**
* Current column in input stream. * Current column in input stream.
*/ */
private int col; private int col;
/** /**
* According errors object. * According errors object.
*/ */
public final Errors errors; public final Errors errors;
public Scanner(Reader r) { public Scanner(Reader r) {
// store reader // store reader
in = r; in = r;
// initialize error handling support // initialize error handling support
errors = new Errors(); errors = new Errors();
line = 1; line = 1;
col = 0; col = 0;
nextCh(); // read 1st char into ch, incr col to 1 nextCh(); // read 1st char into ch, incr col to 1
} }
/** /**
* Adds error message to the list of errors. * Adds error message to the list of errors.
*/ */
public final void error(Token t, Errors.Message msg, Object... msgParams) { public final void error(Token t, Errors.Message msg, Object... msgParams) {
errors.error(t.line, t.col, msg, msgParams); errors.error(t.line, t.col, msg, msgParams);
// reset token content (consistent JUnit tests) // reset token content (consistent JUnit tests)
t.numVal = 0; t.numVal = 0;
t.val = null; t.val = null;
} }
// ================================================ // ================================================
// TODO Exercise UE-P-1: Implement Scanner (next() + private helper methods) // TODO Exercise UE-P-1: Implement Scanner (next() + private helper methods)
// ================================================ // ================================================
// TODO Exercise UE-P-1: Keywords // TODO Exercise UE-P-1: Keywords
/** /**
* Mapping from keyword names to appropriate token codes. * Mapping from keyword names to appropriate token codes.
*/ */
private static final Map<String, Token.Kind> keywords; private static final Map<String, Token.Kind> keywords;
static { static {
keywords = new HashMap<>(); keywords = Map.ofEntries(
} Map.entry("void", void_),
Map.entry("class", class_),
Map.entry("program", program),
Map.entry("if", if_),
Map.entry("else", else_),
Map.entry("while", while_),
Map.entry("read", read),
Map.entry("print", print),
Map.entry("return", return_),
Map.entry("break", break_),
Map.entry("final", final_),
Map.entry("new", new_)
);
}
/** /**
* Returns next token. To be used by parser. * Returns next token. To be used by parser.
*/ */
public Token next() { public Token next() {
// TODO Exercise UE-P-1: implementation of next method // TODO Exercise UE-P-1: implementation of next method
Token t = new Token(none, 1, 1); while (Character.isWhitespace(ch)) {
return t; nextCh();
} }
private void nextCh() { final var ogLine = line;
// TODO Exercise UE-P-1: implementation of nextCh method and other private helper methods final var ogCol = col;
}
// TODO Exercise UE-P-1: private helper methods used by next(), as discussed in the exercise if (isLetter(ch)) {
final var name = readName();
// ----------------------------------------------- return getTokenByName(name, ogLine, ogCol);
}
private boolean isLetter(char c) { if (isDigit(ch)) {
return 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z'; final var number = readNumber();
}
private boolean isDigit(char c) { var token = new Token(Token.Kind.number, ogLine, ogCol);
return '0' <= c && c <= '9'; token.numVal = number;
} token.val = number + "";
// ================================================ return token;
// ================================================ }
if (ch == '\'') {
nextCh();
if (ch == '\\') {
nextCh();
final var charContent = switch (ch) {
case 'n' -> '\n';
case 'r' -> '\r';
case 't' -> '\t';
case '\\' -> '\\';
case '\'' -> '\'';
default -> ' ';
};
final var token = new Token(charConst, ogLine, ogCol);
token.val = charContent + "";
token.numVal = charContent;
nextCh();
nextCh();
return token;
}
final var charContent = ch;
if (charContent == LF || charContent == EOF || charContent == '\'') {
final var token = new Token(charConst, ogLine, ogCol);
final var message = switch (charContent) {
case LF -> Errors.Message.ILLEGAL_LINE_END;
case EOF -> Errors.Message.EOF_IN_CHAR;
case '\'' -> Errors.Message.EMPTY_CHARCONST;
default -> null;
};
error(token, message);
token.val = '\0' + "";
token.numVal = 0;
if (charContent == '\'') {
nextCh();
}
return token;
}
nextCh();
if (ch != '\'') {
final var token = new Token(charConst, ogLine, ogCol);
error(token, Errors.Message.MISSING_QUOTE);
token.val = '\0' + "";
token.numVal = 0;
return token;
}
nextCh();
final var token = new Token(charConst, ogLine, ogCol);
token.val = charContent + "";
token.numVal = charContent;
return token;
}
final var ogChar = ch;
nextCh();
return switch(ogChar) {
case ';' -> new Token(Token.Kind.semicolon, ogLine, ogCol);
case ',' -> new Token(Token.Kind.comma, ogLine, ogCol);
case '.' -> new Token(Token.Kind.period, ogLine, ogCol);
case '{' -> new Token(Token.Kind.lbrace, ogLine, ogCol);
case '}' -> new Token(Token.Kind.rbrace, ogLine, ogCol);
case (char) -1 -> new Token(Token.Kind.eof, ogLine, ogCol);
case '=' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.eql, ogLine, ogCol);
}
yield new Token(Token.Kind.assign, line, col);
}
case '+' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.plusas, ogLine, ogCol);
}
if (ch == '+') {
nextCh();
yield new Token(Token.Kind.pplus, ogLine, ogCol);
}
yield new Token(Token.Kind.plus, ogLine, ogCol);
}
case '-' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.minusas, ogLine, ogCol);
}
if (ch == '-') {
nextCh();
yield new Token(Token.Kind.mminus, ogLine, ogCol);
}
yield new Token(Token.Kind.minus, ogLine, ogCol);
}
case '*' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.timesas, ogLine, ogCol);
}
yield new Token(Token.Kind.times, ogLine, ogCol);
}
case '/' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.slashas, ogLine, ogCol);
}
yield new Token(Token.Kind.slash, ogLine, ogCol);
}
case '%' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.remas, ogLine, ogCol);
}
yield new Token(Token.Kind.rem, ogLine, ogCol);
}
case '!' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.neq, ogLine, ogCol);
}
error(new Token(none, line, col), Errors.Message.INVALID_CHAR);
yield next();
}
case '>' -> {
if (ch == '=') {
nextCh();
yield new Token(Token.Kind.geq, ogLine, ogCol);
}
yield new Token(Token.Kind.gtr, ogLine, ogCol);
}
case '<' -> {
if (ch == '<') {
nextCh();
yield new Token(Token.Kind.leq, ogLine, ogCol);
}
yield new Token(Token.Kind.lss, ogLine, ogCol);
}
case '&' -> {
if (ch == '&') {
nextCh();
yield new Token(Token.Kind.and, ogLine, ogCol);
}
error(new Token(none, line, col), Errors.Message.INVALID_CHAR);
yield next();
}
case '|' -> {
if (ch == '|') {
nextCh();
yield new Token(Token.Kind.and, ogLine, ogCol);
}
error(new Token(none, line, col), Errors.Message.INVALID_CHAR);
yield next();
}
default -> {
error(new Token(none, line, col), Errors.Message.INVALID_CHAR);
yield next();
}
};
}
private void nextCh() {
// TODO Exercise UE-P-1: implementation of nextCh method and other private helper methods
try {
final var intChar = in.read();
final var nextChar = (char) intChar;
if (ch == '\n') {
line++;
col = 0;
}
col++;
ch = nextChar;
} catch (IOException e) {
System.err.println("Could not read Stream");
}
}
// TODO Exercise UE-P-1: private helper methods used by next(), as discussed in the exercise
// -----------------------------------------------
private boolean isLetter(char c) {
return 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z';
}
private boolean isDigit(char c) {
return '0' <= c && c <= '9';
}
public String readName() {
final var builder = new StringBuilder();
while (isLetter(ch)) {
builder.append(ch);
nextCh();
}
return builder.toString();
}
public int readNumber() {
final var builder = new StringBuilder();
while (isDigit(ch)) {
builder.append(ch);
nextCh();
}
return Integer.parseInt(builder.toString());
}
private Token getTokenByName(String name, int line, int col) {
final var kind = keywords.getOrDefault(name, Token.Kind.ident);
var token = new Token(kind, line, col);
if (kind == Token.Kind.ident) {
token.val = name;
}
return token;
}
// ================================================
// ================================================
} }