The structure of a Gosu program

Metaline as first line

Gosu programs support a single line at the beginning of the program for specifying the executable with which to run a file. This line is for compliance with the UNIX standard for shell script files. The metaline is optional. If present, this line must be the first line of the program. The metaline looks like the following:

#!/usr/bin/env gosu

The # character that begins the metaline does not start a comment line in Gosu programs. The # character is not a valid line-comment start symbol.

Functions in a Gosu program

Your Gosu program can define functions in the same file and call those functions.

For example, the following program creates a function and calls the function twice:

print(sum(10, 4, 7));
print(sum(222, 4, 3));

 function sum(a: int, b: int, c: int) : int {
  return a + b + c;
}

Running this program prints:

21
229