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diff --git a/node_modules/tslib/docs/generator.md b/node_modules/tslib/docs/generator.md deleted file mode 100644 index 88ffb08e2..000000000 --- a/node_modules/tslib/docs/generator.md +++ /dev/null @@ -1,486 +0,0 @@ -# The `__generator` helper
-
-The `__generator` helper is a function designed to support TypeScript's down-level emit for
-async functions when targeting ES5 and earlier. But how, exactly, does it work?
-
-Here's the body of the `__generator` helper:
-
-```js
-__generator = function (thisArg, body) {
- var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t;
- return { next: verb(0), "throw": verb(1), "return": verb(2) };
- function verb(n) { return function (v) { return step([n, v]); }; }
- function step(op) {
- if (f) throw new TypeError("Generator is already executing.");
- while (_) try {
- if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
- if (y = 0, t) op = [0, t.value];
- switch (op[0]) {
- case 0: case 1: t = op; break;
- case 4: _.label++; return { value: op[1], done: false };
- case 5: _.label++; y = op[1]; op = [0]; continue;
- case 7: op = _.ops.pop(); _.trys.pop(); continue;
- default:
- if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
- if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
- if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
- if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
- if (t[2]) _.ops.pop();
- _.trys.pop(); continue;
- }
- op = body.call(thisArg, _);
- } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
- if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
- }
-};
-```
-
-And here's an example of it in use:
-
-```ts
-// source
-async function func(x) {
- try {
- await x;
- }
- catch (e) {
- console.error(e);
- }
- finally {
- console.log("finally");
- }
-}
-
-// generated
-function func(x) {
- return __awaiter(this, void 0, void 0, function () {
- var e_1;
- return __generator(this, function (_a) {
- switch (_a.label) {
- case 0:
- _a.trys.push([0, 1, 3, 4]);
- return [4 /*yield*/, x];
- case 1:
- _a.sent();
- return [3 /*break*/, 4];
- case 2:
- e_1 = _a.sent();
- console.error(e_1);
- return [3 /*break*/, 4];
- case 3:
- console.log("finally");
- return [7 /*endfinally*/];
- case 4: return [2 /*return*/];
- }
- });
- });
-}
-```
-
-There is a lot going on in this function, so the following will break down what each part of the
-`__generator` helper does and how it works.
-
-# Opcodes
-
-The `__generator` helper uses opcodes which represent various operations that are interpreted by
-the helper to affect its internal state. The following table lists the various opcodes, their
-arguments, and their purpose:
-
-| Opcode | Arguments | Purpose |
-|----------------|-----------|--------------------------------------------------------------------------------------------------------------------------------|
-| 0 (next) | *value* | Starts the generator, or resumes the generator with *value* as the result of the `AwaitExpression` where execution was paused. |
-| 1 (throw) | *value* | Resumes the generator, throwing *value* at `AwaitExpression` where execution was paused. |
-| 2 (return) | *value* | Exits the generator, executing any `finally` blocks starting at the `AwaitExpression` where execution was paused. |
-| 3 (break) | *label* | Performs an unconditional jump to the specified label, executing any `finally` between the current instruction and the label. |
-| 4 (yield) | *value* | Suspends the generator, setting the resume point at the next label and yielding the value. |
-| 5 (yieldstar) | *value* | Suspends the generator, setting the resume point at the next label and delegating operations to the supplied value. |
-| 6 (catch) | *error* | An internal instruction used to indicate an exception that was thrown from the body of the generator. |
-| 7 (endfinally) | | Exits a finally block, resuming any previous operation (such as a break, return, throw, etc.) |
-
-# State
-The `_`, `f`, `y`, and `t` variables make up the persistent state of the `__generator` function. Each variable
-has a specific purpose, as described in the following sections:
-
-## The `_` variable
-The `__generator` helper must share state between its internal `step` orchestration function and
-the `body` function passed to the helper.
-
-```ts
-var _ = {
- label: 0,
- sent: function() {
- if (t[0] & 1) // NOTE: true for `throw`, but not `next` or `catch`
- throw t[1];
- return sent[1];
- },
- trys: [],
- ops: []
-};
-```
-
-The following table describes the members of the `_` state object and their purpose:
-
-| Name | Description |
-|---------|---------------------------------------------------------------------------------------------------------------------------|
-| `label` | Specifies the next switch case to execute in the `body` function. |
-| `sent` | Handles the completion result passed to the generator. |
-| `trys` | A stack of **Protected Regions**, which are 4-tuples that describe the labels that make up a `try..catch..finally` block. |
-| `ops` | A stack of pending operations used for `try..finally` blocks. |
-
-The `__generator` helper passes this state object to the `body` function for use with switching
-between switch cases in the body, handling completions from `AwaitExpression`, etc.
-
-## The `f` variable
-The `f` variable indicates whether the generator is currently executing, to prevent re-entry of
-the same generator during its execution.
-
-## The `y` variable
-The `y` variable stores the iterator passed to a `yieldstar` instruction to which operations should be delegated.
-
-## The `t` variable
-The `t` variable is a temporary variable that stores one of the following values:
-
-- The completion value when resuming from a `yield` or `yield*`.
-- The error value for a catch block.
-- The current **Protected Region**.
-- The verb (`next`, `throw`, or `return` method) to delegate to the expression of a `yield*`.
-- The result of evaluating the verb delegated to the expression of a `yield*`.
-
-> NOTE: None of the above cases overlap.
-
-# Protected Regions
-A **Protected Region** is a region within the `body` function that indicates a
-`try..catch..finally` statement. It consists of a 4-tuple that contains 4 labels:
-
-| Offset | Description |
-|--------|-----------------------------------------------------------------------------------------|
-| 0 | *Required* The label that indicates the beginning of a `try..catch..finally` statement. |
-| 1 | *Optional* The label that indicates the beginning of a `catch` clause. |
-| 2 | *Optional* The label that indicates the beginning of a `finally` clause. |
-| 3 | *Required* The label that indicates the end of the `try..catch..finally` statement. |
-
-# The generator object
-The final step of the `__generator` helper is the allocation of an object that implements the
-`Generator` protocol, to be used by the `__awaiter` helper:
-
-```ts
-return { next: verb(0), "throw": verb(1), "return": verb(2) };
-function verb(n) { return function (v) { return step([n, v]); }; }
-```
-
-This object translates calls to `next`, `throw`, and `return` to the appropriate Opcodes and
-invokes the `step` orchestration function to continue execution. The `throw` and `return` method
-names are quoted to better support ES3.
-
-# Orchestration
-The `step` function is the main orechestration mechanism for the `__generator` helper. It
-interprets opcodes, handles **protected regions**, and communicates results back to the caller.
-
-Here's a closer look at the `step` function:
-
-```ts
-function step(op) {
- if (f) throw new TypeError("Generator is already executing.");
- while (_) try {
- if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
- if (y = 0, t) op = [0, t.value];
- switch (op[0]) {
- case 0: case 1: t = op; break;
- case 4: _.label++; return { value: op[1], done: false };
- case 5: _.label++; y = op[1]; op = [0]; continue;
- case 7: op = _.ops.pop(); _.trys.pop(); continue;
- default:
- if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
- if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
- if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
- if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
- if (t[2]) _.ops.pop();
- _.trys.pop(); continue;
- }
- op = body.call(thisArg, _);
- } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
- if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
-}
-```
-
-The main body of `step` exists in a `while` loop. This allows us to continually interpret
-operations until we have reached some completion value, be it a `return`, `await`, or `throw`.
-
-## Preventing re-entry
-The first part of the `step` function is used as a check to prevent re-entry into a currently
-executing generator:
-
-```ts
-if (f) throw new TypeError("Generator is already executing.");
-```
-
-## Running the generator
-The main body of the `step` function consists of a `while` loop which continues to evaluate
-instructions until the generator exits or is suspended:
-
-```ts
-while (_) try ...
-```
-
-When the generator has run to completion, the `_` state variable will be cleared, forcing the loop
-to exit.
-
-## Evaluating the generator body.
-```ts
-try {
- ...
- op = body.call(thisArg, _);
-}
-catch (e) {
- op = [6, e];
- y = 0;
-}
-finally {
- f = t = 0;
-}
-```
-
-Depending on the current operation, we re-enter the generator body to start or continue execution.
-Here we invoke `body` with `thisArg` as the `this` binding and the `_` state object as the only
-argument. The result is a tuple that contains the next Opcode and argument.
-
-If evaluation of the body resulted in an exception, we convert this into an Opcode 6 ("catch")
-operation to be handled in the next spin of the `while` loop. We also clear the `y` variable in
-case it is set to ensure we are no longer delegating operations as the exception occurred in
-user code *outside* of, or at the function boundary of, the delegated iterator (otherwise the
-iterator would have handled the exception itself).
-
-After executing user code, we clear the `f` flag that indicates we are executing the generator,
-as well as the `t` temporary value so that we don't hold onto values sent to the generator for
-longer than necessary.
-
-Inside of the `try..finally` statement are a series of statements that are used to evaluate the
-operations of the transformed generator body.
-
-The first thing we do is mark the generator as executing:
-
-```ts
-if (f = 1, ...)
-```
-
-Despite the fact this expression is part of the head of an `if` statement, the comma operator
-causes it to be evaluated and the result thrown out. This is a minification added purely to
-reduce the overall footprint of the helper.
-
-## Delegating `yield*`
-
-The first two statements of the `try..finally` statement handle delegation for `yield*`:
-
-```ts
-if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
-if (y = 0, t) op = [0, t.value];
-```
-
-If the `y` variable is set, and `y` has a `next`, `throw`, or `return` method (depending on the
-current operation), we invoke this method and store the return value (an IteratorResult) in `t`.
-
-If `t` indicates it is a yielded value (e.g. `t.done === false`), we return `t` to the caller.
-If `t` indicates it is a returned value (e.g. `t.done === true`), we mark the operation with the
-`next` Opcode, and the returned value.
-If `y` did not have the appropriate method, or `t` was a returned value, we reset `y` to a falsey
-value and continue processing the operation.
-
-## Handling operations
-
-The various Opcodes are handled in the following switch statement:
-
-```ts
-switch (op[0]) {
- case 0: case 1: t = op; break;
- case 4: _.label++; return { value: op[1], done: false };
- case 5: _.label++; y = op[1]; op = [0]; continue;
- case 7: op = _.ops.pop(); _.trys.pop(); continue;
- default:
- if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
- if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
- if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
- if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
- if (t[2]) _.ops.pop();
- _.trys.pop(); continue;
-}
-```
-
-The following sections describe the various Opcodes:
-
-### Opcode 0 ("next") and Opcode 1 ("throw")
-```ts
-case 0: // next
-case 1: // throw
- t = op;
- break;
-```
-
-Both Opcode 0 ("next") and Opcode 1 ("throw") have the same behavior. The current operation is
-stored in the `t` variable and the `body` function is invoked. The `body` function should call
-`_.sent()` which will evaluate the appropriate completion result.
-
-### Opcode 4 ("yield")
-```ts
-case 4: // yield
- _.label++;
- return { value: op[1], done: false };
-```
-
-When we encounter Opcode 4 ("yield"), we increment the label by one to indicate the point at which
-the generator will resume execution. We then return an `IteratorResult` whose `value` is the
-yielded value, and `done` is `false`.
-
-### Opcode 5 ("yieldstar")
-```ts
-case 5: // yieldstar
- _.label++;
- y = op[1];
- op = [0];
- continue;
-```
-
-When we receive Opcode 5 ("yieldstar"), we increment the label by one to indicate the point at which
-the generator will resume execution. We then store the iterator in `op[1]` in the `y` variable, and
-set the operation to delegate to Opcode 0 ("next") with no value. Finally, we continue execution at
-the top of the loop to start delegation.
-
-### Opcode 7 ("endfinally")
-```ts
-case 7:
- op = _.ops.pop();
- _.trys.pop();
- continue;
-```
-
-Opcode 7 ("endfinally") indicates that we have hit the end of a `finally` clause, and that the last
-operation recorded before entering the `finally` block should be evaluated.
-
-### Opcode 2 ("return"), Opcode 3 ("break"), and Opcode 6 ("catch")
-```ts
-default:
- if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) {
- _ = 0;
- continue;
- }
- if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) {
- _.label = op[1];
- break;
- }
- if (op[0] === 6 && _.label < t[1]) {
- _.label = t[1];
- t = op;
- break;
- }
- if (t && _.label < t[2]) {
- _.label = t[2];
- _.ops.push(op);
- break;
- }
- if (t[2])
- _.ops.pop();
- _.trys.pop();
- continue;
-}
-```
-
-The handling for Opcode 2 ("return"), Opcode 3 ("break") and Opcode 6 ("catch") is more
-complicated, as we must obey the specified runtime semantics of generators. The first line in this
-clause gets the current **Protected Region** if found and stores it in the `t` temp variable:
-
-```ts
-if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && ...) ...
-```
-
-The remainder of this statement, as well as the following by several `if` statements test for more
-complex conditions. The first of these is the following:
-
-```ts
-if (!(t = ...) && (op[0] === 6 || op[0] === 2)) {
- _ = 0;
- continue;
-}
-```
-
-If we encounter an Opcode 6 ("catch") or Opcode 2 ("return"), and we are not in a protected region,
-then this operation completes the generator by setting the `_` variable to a falsey value. The
-`continue` statement resumes execution at the top of the `while` statement, which will exit the loop
-so that we continue execution at the statement following the loop.
-
-```ts
-if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) {
- _.label = op[1];
- break;
-}
-```
-
-The `if` statement above handles Opcode 3 ("break") when we are either not in a **protected region**, or
-are performing an unconditional jump to a label inside of the current **protected region**. In this case
-we can unconditionally jump to the specified label.
-
-```ts
-if (op[0] === 6 && _.label < t[1]) {
- _.label = t[1];
- t = op;
- break;
-}
-```
-
-The `if` statement above handles Opcode 6 ("catch") when inside the `try` block of a **protected
-region**. In this case we jump to the `catch` block, if present. We replace the value of `t` with
-the operation so that the exception can be read as the first statement of the transformed `catch`
-clause of the transformed generator body.
-
-```ts
-if (t && _.label < t[2]) {
- _.label = t[2];
- _.ops.push(op);
- break;
-}
-```
-
-This `if` statement handles all Opcodes when in a **protected region** with a `finally` clause.
-As long as we are not already inside the `finally` clause, we jump to the `finally` clause and
-push the pending operation onto the `_.ops` stack. This allows us to resume execution of the
-pending operation once we have completed execution of the `finally` clause, as long as it does not
-supersede this operation with its own completion value.
-
-```ts
-if (t[2])
- _.ops.pop();
-```
-
-Any other completion value inside of a `finally` clause will supersede the pending completion value
-from the `try` or `catch` clauses. The above `if` statement pops the pending completion from the
-stack.
-
-```ts
-_.trys.pop();
-continue;
-```
-
-The remaining statements handle the point at which we exit a **protected region**. Here we pop the
-current **protected region** from the stack and spin the `while` statement to evaluate the current
-operation again in the next **protected region** or at the function boundary.
-
-## Handling a completed generator
-Once the generator has completed, the `_` state variable will be falsey. As a result, the `while`
-loop will terminate and hand control off to the final statement of the orchestration function,
-which deals with how a completed generator is evaluated:
-
-```ts
-if (op[0] & 5)
- throw op[1];
-return { value: op[0] ? op[1] : void 0, done: true };
-```
-
-If the caller calls `throw` on the generator it will send Opcode 1 ("throw"). If an exception
-is uncaught within the body of the generator, it will send Opcode 6 ("catch"). As the generator has
-completed, it throws the exception. Both of these cases are caught by the bitmask `5`, which does
-not collide with the only two other valid completion Opcodes.
-
-If the caller calls `next` on the generator, it will send Opcode 0 ("next"). As the generator has
-completed, it returns an `IteratorResult` where `value` is `undefined` and `done` is true.
-
-If the caller calls `return` on the generator, it will send Opcode 2 ("return"). As the generator
-has completed, it returns an `IteratorResult` where `value` is the value provided to `return`, and
-`done` is true.
\ No newline at end of file |