Getting Started

A Mew program is a file called main.mew.

use std;
  
println("Hello, world!");

Run it:

mew main.mew

Hello, world!

run is the default command, so a bare path runs the program. mew run main.mew does the same thing.

The entry point

A program starts at the top of main.mew and runs its statements in order.

Only that file may contain them. Every other file in the compilation holds declarations, and a statement outside a declaration there is an error.

// file: helper.mew
use std;
  
pub fn greet(name: string) -> void {
    println($"Hello, {name}!");
}
  
// file: main.mew
#load "helper.mew"
  
greet("world");

Exit code

A return at the top level ends the program and becomes its exit code. It has to be an int, since that is all an exit code can carry.

use std;
  
println("giving up");
return 1;

Reaching the end of main.mew without a return exits with 0.

Building without running

mew build compiles the program and prints where it put it, without launching anything.

mew build main.mew

/home/you/hello/.mew/main.dll

The build goes in a .mew directory beside the file the program starts from. The leading dot matters: a directory whose name starts with one is skipped when sources are discovered, so a build never becomes part of the next compilation.

A build is skipped entirely when nothing that decides the program has changed, so running the same unchanged program twice only compiles it once.