A visual machine run in ES env like Node/Browser
npm install es-vmbootstrap - vm start.
load program - load the defined statement into vm.
program run - run the statement.
halt - vm stops if program end or meets error.
Javascript
const {ESVM} = require('esvm')
// Get vm instance.
const vk = new ESVM();
// Define a simple statement.
const program = new Statement();
program.execute = function* (vm) {
yield 'hello';
};
// Load the statement into vm.
vk.$loadProgram(program);
// Run the statement.
// VM will halt when execution completed.
vk.$launch();
`
statement
In ESVM, we define a statement template and it can be easily used to implement more complicated statement.
User can define their own statement class by inheriting from Statement class and then override the constructor、execute function.
Example
`Javascript
const {Statement} = require('esvm');
// Define a simple statement.
const program = new Statement();
// Implement execute function.
program.execute = function* (vm) {
yield [statement_1];
yield [statement_2];
...
yield [statement_n];
};
`
rpc
ESVM can send message to remote and get response synchronouslys or asynchronously.
fetch() is called to start a RPC request, then an event named fetch will be emmited,
vm will be blocked and wait for response from remote.
Response is in a format like {ret, err} and we can simplely set the value through rpc.setRet(val) & rpc.setDate(val)
Default Response
{ret: null, err: null}
Async Call
Pass a process function to async(), and the function will be wrapped with a promise
by async() implementation. Promise can be returned from process function, and it will
be executed after the previous promise.
`Javascript
rpc.async(vm => {
// Can rpc.setRet & setError in async().
// Use vm to access vm-instance of the rpc anywhere.
// Some code here
...
return new Promise((resolve,reject) => {
// Some code ...
});
});
``