Macro opcodes

macro_rules! opcodes {
    ($name:ident, $desc:literal) => { ... };
    {
        $version:ident,
        $((
            $opcode:expr,
            $name:ident,
            $gas:expr,
            $input:expr,
            $output:expr,
            $desc:literal,
            $since:ident,
            $group:ident
        )),+
    } => { ... };
}

Ethereum virtual machine opcode generator.