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Getting Started

A Mew program is a file called main.mew.

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.

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

greet("world");
note

The rule is the filename, and it is compared exactly. Main.mew is not an entry point.

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.

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.