It would be nice to have `error.prettyStack` and
`Execution.getPrettyStack()` / `Error.capturePrettyStackTrace(..)` to
capture same nice stack trace as `console.error(..)` does.

Generally problem with `error.stack` is that is is plain-text value, and it
does not take into account source mapping. All this problems are solved in
`console.error(...)` method. It prints nice stack trace with links to
source files (including that, which provided by source mapping), but bad
thing with it - that there is no standard API to capture it (in same nice
form). So for me it looks like fair solution - to define some
implementation-specific `PrettyStack` object/class with some basic methods
like `stk1.concat(stk2)` and (`Array`/`String` -like) `stk.slice(..)`. And
say that `PrettyStack` internal structure is completely
implementation-specific, but the only requirement is that it should be
perfect compatibility between `PrettyStack` and `console` object. So that
the following code snippet should produce 3 log messages with the same nice
stack-trace included/printed:

```js
console.error("error message with stack trace");
console.info("info message with stack trace", Execution.getPrettyStack());
console.debug("debug message with stack trace", new Error().prettyStack);
```

Main use case of this API is to facilitate some "home made" executable
commands queue. In fact in this case you may want to see async-like
stack-trace (where put-to-queue action stack-trace should be concatenated
to command-execution stack-trace, and actually that concatenated async-like
stack trace would be more informative then having just command-execution
failure stack-trace alone).

In case if such pretty stack API exists, it would be possible to queue
command-entry which includes current stack trace like `queueAction:
(_actionFunction_) -> {internal_queue.push({callerStack:
Execution.getPrettyStack(), funcToRun: _actionFunction_})}`. And in case if
action from queue failed it would be possible to equip that failure with
extra (async-like) stack-trace information, writing something like:
`err.asyncPrettyStack = err.prettyStack.concat(_queueEntry_.callerStack)`
(or more complete: `if (err.asyncPrettyStack == null) {err.asyncPrettyStack
= err.prettyStack}; err.asyncPrettyStack =
err.asyncPrettyStack.concat(_queueEntry_.callerStack);`).

Also it would be nice to have something like "base-stack-trace"
("context-stack-trace") which should be programmatically (freely)
controlled by code, and automatically appended to current execution
stack-trace (like it does for async-like calls to ajax-api, setTimeout-api,
etc). So that it may look like:

```js
const runQueueEntry = function({callerStack: entryCallerPrettyStack,
funcToRun: entryActionFunction}) {
  // so inside of entryActionFunction execution Execution.getPrettyStack()
should be
  // concatenation of entryCallerPrettyStack and actual current
("not-async") PrettyStack
  Execution.runWithContext({basePrettyStack: entryCallerPrettyStack},
entryActionFunction);
}
```
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.mozilla.org/pipermail/es-discuss/attachments/20170606/74d085f2/attachment.html>

It would be nice to have `error.prettyStack` and `Execution.getPrettyStack()` / `Error.capturePrettyStackTrace(..)` to capture same nice stack trace as `console.error(..)` does.

Generally problem with `error.stack` is that is is plain-text value, and it does not take into account source mapping. All this problems are solved in `console.error(...)` method. It prints nice stack trace with links to source files (including that, which provided by source mapping), but bad thing with it - that there is no standard API to capture it (in same nice form). So for me it looks like fair solution - to define some implementation-specific `PrettyStack` object/class with some basic methods like `stk1.concat(stk2)` and (`Array`/`String` -like) `stk.slice(..)`. And say that `PrettyStack` internal structure is completely implementation-specific, but the only requirement is that it should be perfect compatibility between `PrettyStack` and `console` object. So that the following code snippet should produce 3 log messages with the same nice stack-trace included/printed:

```js
console.error("error message with stack trace");
console.info("info message with stack trace", Execution.getPrettyStack());
console.debug("debug message with stack trace", new Error().prettyStack);
```

Main use case of this API is to facilitate some "home made" executable commands queue. In fact in this case you may want to see async-like stack-trace (where put-to-queue action stack-trace should be concatenated to command-execution stack-trace, and actually that concatenated async-like stack trace would be more informative then having just command-execution failure stack-trace alone).

In case if such pretty stack API exists, it would be possible to queue command-entry which includes current stack trace like `queueAction: (_actionFunction_) -> {internal_queue.push({callerStack: Execution.getPrettyStack(), funcToRun: _actionFunction_})}`. And in case if action from queue failed it would be possible to equip that failure with extra (async-like) stack-trace information, writing something like: `err.asyncPrettyStack = err.prettyStack.concat(_queueEntry_.callerStack)` (or more complete: `if (err.asyncPrettyStack == null) {err.asyncPrettyStack = err.prettyStack}; err.asyncPrettyStack = err.asyncPrettyStack.concat(_queueEntry_.callerStack);`). 

Also it would be nice to have something like "base-stack-trace" ("context-stack-trace") which should be programmatically (freely) controlled by code, and automatically appended to current execution stack-trace (like it happens for async-like calls to ajax-api, setTimeout-api, etc). So that it may look like:

```js
const runQueueEntry = function({callerStack: entryCallerPrettyStack, funcToRun: entryActionFunction}) {
  // so inside of entryActionFunction execution Execution.getPrettyStack() should be 
  // concatenation of entryCallerPrettyStack and actual current ("not-async") PrettyStack
  Execution.runWithContext({basePrettyStack: entryCallerPrettyStack}, entryActionFunction);
}
```

It would be nice to have `error.prettyStack` and `Execution.getPrettyStack()` / `Error.capturePrettyStackTrace(..)` to capture same nice stack trace as `console.error(..)` does.

Generally problem with `error.stack` is that is is plain-text value, and it does not take into account source mapping. All this problems are solved in `console.error(...)` method. It prints nice stack trace with links to source files (including that, which provided by source mapping), but bad thing with it - that there is no standard API to capture it (in same nice form). So for me it looks like fair solution - to define some implementation-specific `PrettyStack` object/class with some basic methods like `stk1.concat(stk2)` and (`Array`/`String` -like) `stk.slice(..)`. And say that `PrettyStack` internal structure is completely implementation-specific, but the only requirement is that it should be perfect compatibility between `PrettyStack` and `console` object. So that the following code snippet should produce 3 log messages with the same nice stack-trace included/printed:

```js
console.error("error message with stack trace");
console.info("info message with stack trace", Execution.getPrettyStack());
console.debug("debug message with stack trace", new Error().prettyStack);
```

Main use case of this API is to facilitate some "home made" executable commands queue. In fact in this case you may want to see async-like stack-trace (where put-to-queue action stack-trace should be concatenated to command-execution stack-trace, and actually that concatenated async-like stack trace would be more informative then having just command-execution failure stack-trace alone).

In case if such pretty stack API exists, it would be possible to queue command-entry which includes current stack trace like `queueAction: (_actionFunction_) -> {internal_queue.push({callerStack: Execution.getPrettyStack(), funcToRun: _actionFunction_})}`. And in case if action from queue failed it would be possible to equip that failure with extra (async-like) stack-trace information, writing something like: `err.asyncPrettyStack = err.prettyStack.concat(_queueEntry_.callerStack)` (or more complete: `if (err.asyncPrettyStack == null) {err.asyncPrettyStack = err.prettyStack}; err.asyncPrettyStack = err.asyncPrettyStack.concat(_queueEntry_.callerStack);`). 

Also it would be nice to have something like "base-stack-trace" ("context-stack-trace") which should be programmatically (freely) controlled by code, and automatically appended to current execution stack-trace (like it does for async-like calls to ajax-api, setTimeout-api, etc). So that it may look like:

```js
const runQueueEntry = function({callerStack: entryCallerPrettyStack, funcToRun: entryActionFunction}) {
  // so inside of entryActionFunction execution Execution.getPrettyStack() should be 
  // concatenation of entryCallerPrettyStack and actual current ("not-async") PrettyStack
  Execution.runWithContext({basePrettyStack: entryCallerPrettyStack}, entryActionFunction);
}
```