private int lineNumber, column;

private CharSequence line;

@Setter

private String filename;

public SyntaxError(String message, String filename, int lineNumber, int column, CharSequence line) {

super(message);

this.filename = filename;

this.lineNumber = lineNumber;

this.column = column;

this.line = line;

}

@Override

public String getMessage() {

return super.getMessage() + "\n" + (filename == null? "" : "in file " + filename + " ") + "on line " + lineNumber + ":" + formatLine(line, column);

}

private static String formatLine(CharSequence line, int column) {

var sb = new StringBuilder("\n ");

for(int i = 0; i < line.length(); i++) {

char c = line.charAt(i);

if(c == '\t') {

sb.append(" ");

} else if(Character.isWhitespace(c)) {

sb.append(' ');

} else {

sb.append(c);

}

}

sb.append("\n ");

if(column > line.length()) {

column = line.length();

}

for(int i = 1; i < column; i++) {

if(line.charAt(i) == '\t') {

sb.append(" ");

} else {

sb.append(' ');

}

}

sb.append('^');

return sb.toString();

}