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Welcome to the MetaScript wiki! For now, the wiki contains a few non-trivial insights on writing meta.

Short statements

//? if (NODE)
buffer.writeInt8(offset, value);
//? else
view.setInt8(value, offset);

This will actually work without using curly braces because each source line is wrapped by a dedicated write(...) call, resulting in the following meta program:

if (NODE)
  write('buffer.writeInt8(offset, value);\n');
else
  write('view.setInt8(value, offset);\n');

White-spaces and line breaks

The MetaScript compiler makes sure to retain any white spaces and line breaks, except if a meta line or block is the only contents of a line, in which case the line break and white spaces will be skipped. In the example from above:

if (true) {
    //? if (NODE)
    buffer.writeInt8(offset, value);
    //? else
    view.setInt8(value, offset);
}

the result will not contain any white spaces or new lines where the meta statements are, like, for NODE=true, so:

if (true) {
    buffer.writeInt8(offset, value);
}

But if you explicitly require indentation, you may use the indent(str:string, indent:string|number):string utility:

    //? write(indent('hi!', 4))

which will result in:

    hi!

The __ variable

When inspecting the generated meta program, you will notice that the variable __ is used quite frequently. It stores the indentation level of the last meta block processed. For example ...

//? if (NODE)
    //? include("node-stuff.js");
//? else
    //? include("browser-stuff.js");

... will indent the contents of the included filesby four spaces (just like before //?), while ...

/*? if (NODE)
    include("node-stuff.js");
else
    include("browser-stuff.js"); */

will not, just like before /*?. When creating custom utility functions, it's of course safe to use this variable on your own.