lexical-syntax.md

Lexical Syntax

The following pages describe the Lexical Syntax of Dyvil Files.

Semicolon Inference

Much like in Java, statements have to be terminated using semicolons ;, usually at the end of a line. In Dyvil however, these semicolons can be omitted in many cases. This is because of a process known as Semicolon Inference, which happens before the Compiler parses Dyvil Files.

Example:

public class MyClass
{
    var value: int = 0   // ;

    static func main(args: [String]) -> void
    {
        var i = 10              // ;
        print i                 // ;

        let my = new MyClass    // ;

        print(                  // 1
                my,             // 2
                my.             // 3
                    value,
                "value")        // ;

        print;                  // 4

        print "\(               // 5
                    my)"        // ;

        if (i >= 20)            // 6
        {
            print "\(i) is greater than 20!" // ;
        }
    }
}

In the above example, semicolons are implicit in all cases where they are shown in comments. The parses notices that the statement is finished and a newline is present, and thus inserts a semicolon for you. While this usually happens at the end of a line, there are a few exceptions.

Semicolons are not inserted if

• the last token before the newline is
  • an opening bracket (, [ or { (1).
  • a period . (2).
  • a comma , (3).
  • a semicolon ; (4).
  • a keyword, excluding
    • true and false.
    • break and continue.
    • this and super.
  • the start or a part of a String Interpolation Literal (5).
• the first token of the next line is
  • a period ..
  • a comma ,.
  • a semicolon ;.
  • a part or the end of a String Interpolation Literal.
  • an opening curly bracket { (6).
  • a closing bracket ), ] or }.

If there is one or more empty lines between two tokens, a semicolon will always be inserted between them.