#
Create Modules
Modules are stored in vm->_modules
and vm->_lazy_modules
.
They are both dict-like objects.
#
Lazy modules
A lazy module is a python source file.
It is compiled and executed when it is imported.
Use []
operator to add a lazy module.
vm->_lazy_modules["test"] = "pi = 3.14";
import test
print(test.pi) # 3.14
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Native modules
A native module is a module written in c++ or mixed c++/python. Native modules are always compiled and executed when the VM is created.
To creata a native module, use vm->new_module(Str name)
.
PyObject* mod = vm->new_module("test");
mod->attr().set("pi", py_var(vm, 3.14));
vm->bind(mod, "add(a: int, b: int)",
[](VM* vm, ArgsView args){
int a = py_cast<int>(vm, args[0]);
int b = py_cast<int>(vm, args[1]);
return py_var(vm, a + b);
});
import test
print(test.pi) # 3.14
print(test.add(1, 2)) # 3
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Module resolution order
When you do import
a module, the VM will try to find it in the following order:
- Search
vm->_modules
, if found, return it. - Search
vm->_lazy_modules
, if found, compile and execute it, then return it. - Try
vm->_import_handler
.
#
Customized import handler
You can use vm->_import_handler
to provide a custom import handler for the 3rd step.
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Import module via cpp
You can use vm->py_import
to import a module.
This is equivalent to import
in python.
Return the module object if success.