Improve the code on throwing exceptions

[mitsuki31]

What's Changed

Options.java

• Changed the parameter on raiseError and raiseErrorMsg methods. More details.

  Comparison

  Before

  void raiseError(Exception);
  void raiseError(Exception, int);
  void raiseErrorMsg(Exception);
  void raiseError(Exception, int);
  

  After

  void raiseError(Throwable);
  void raiseError(Throwable, int);
  void raiseErrorMsg(Throwable);
  void raiseErrorMsg(Throwable, int);
  

Matrix.java

• Added new private attribute/member named cause with Throwable as identifier type.

  private static Throwable cause = null;
  

• Removed all try-catch blocks on several methods.
• Minor updates on javadoc of several methods.

Commits

• Improve the raiseError and raiseErrorMsg (a59ca9d)
• Improve the code on catching exceptions (5cf9f61)
• Added cause as private attribute (ff14d89)
• Remove the duplicate cause variables (7c576a3)
• Remove try-catch on create method (79cf264)
• Remove try-catch on select method (c7a7ff4)
• Remove try-catch on change method (2f37a56)
• Remove try-catch on sum methods (0857039)
• Remove try-catch on sub methods (b67f3a7)
• Remove try-catch on mult methods (5ebc23f)
• Remove try-catch on transpose methods (9f95d4d)
• Remove try-catch on display methods (304a555)
• Remove try-catch on several methods (f5e0196)
• Remove try-catch on get method (ff6a18f)
• Update the version (forced) (7544291)
• Update the version (954a041)
• Update the version (4269773)

Description

Added new (private) attribute named cause with Throwable class as the identifier type.
It's used to holds some exception that could occurs during runtime execution.
So, it makes the code more readable and flexible on catching and throwing the exceptions rather than
using try-catch blocks on everywhere, that makes code more dirty and maybe some peoples
can't understand it.

Removing the try-catch on some methods doesn't make it "a method with non-exceptions", instead it takes the exception and stores it into cause variable (which is private attribute) and then it checks whether the cause is null, if no it will indicates the cause stored some exception and will get raised immediately, otherwise passes it.

Let's take a look this code example below.

public boolean isSquare() {
    /* Here's code that checks the entries of this matrix before comparing its sizes.
     * Rather than using `try-catch` statement that makes code longer,
     * instead create new the exception and store it into `cause` variable.
     */
    if (this.ENTRIES == null) {
        // Create new exception and assign it into `cause`
        cause = new NullMatrixException("the message goes here...");
    }

    /* And here will check the `cause` variable whether it has stored some exception.
     * If `true`, that's indicates the `cause` stored an exception then raise that
     * exception using `raiseError` method, pass otherwise.
     */
    if (cause != null) Options.raiseError(cause);

    return (this.ROWS == this.COLS);
}

[mitsuki31]

Changed the raiseError parameter from Exception ex to Throwable cause, so it can be used by any type of exceptions either RuntimeException and Exception.

This also changed on these following methods:

• raiseError(Exception, int) -> raiseError(Throwable, int)
• raiseErrorMsg(Exception) -> raiseErrorMsg(Throwable)
• raiseErrorMsg(Exception, int) -> raiseErrorMsg(Throwable, int)