def self.operand_of(code)
case code
when /load/, /store/
[:u32, :u32]
when :local_get, :local_set, :local_tee, :global_get, :global_set, :call, :br, :br_if
[:u32]
when :memory_init, :memory_copy
[:u32, :u32]
when :memory_size, :memory_grow, :memory_fill
[:u32]
when :call_indirect
[:u32, :u32]
when :br_table
[:u32_vec, :u32]
when :i32_const
[:i32]
when :i64_const
[:i64]
when :f32_const
[:f32]
when :f64_const
[:f64]
when :if, :block, :loop
[:u8_block]
else
[]
end
end