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hahahahaha this one cracked me up "Writing code without a stack is a lot like driving a car without a brake pedal: you don't realize how badly you need it, unt

hahahahaha this one cracked me up "Writing code without a stack is a lot like driving a car without a brake pedal: you don't realize how badly you need it, until you reach for it and it's not there."

Kenji 11y ago
I didn't really understand that one. First of all, I don't see why a stack really is that indispensable, and secondly, JavaScript does actually have a stack so I don't know how he thinks it's operating stackless - where do the local variables go?
- nolanl 11y ago
  This is what I mean: doSomething(function (err) { doSomethingElse(function (err) { doYetAnotherThing(function (err) { throw new Error( "I don't bubble up to the top of the stack, " + "because there is no stack!"); }); }); }); BTW a great trick is to tick the little "Async" box in the Chrome Dev Tools, so you can get a full stacktrace showing exactly where you came from. It works for both callbacks and promises: http://www.html5rocks.com/en/tutorials/developertools/async-call-stack/ http://www.html5rocks.com/en/tutorials/developertools/async-...
- jerf 11y ago
  In the classic, but widely misunderstood, "Goto Considered Harmful", Dijkstra's point is basically that structure programming is good because it produces a stack and an instruction pointer, which contains an immense quantity of useful information when a crash occurs. Goto is bad in this paper because when it is used as the only control flow construct, in a way difficult for a modern programmer to understand in a world where structured programming won so thoroughly that every language is structured, it produces no stack trace. You get a "Crash On Line 28430", with no clue how you got there. Naive event-based code is somewhat like a goto, in that every time an event comes in, you get a new stack constructed for that event. While you then get a stack if you call functions from the initial handler, every event that comes in whacks the stack afresh. So it isn't "the same as" a goto, but it does hurt the stack. Instead of a stack frame that represents the whole of the program, you get a series of "island" stack frames. In some sense, this is the most fundamental reason why event-based programming is so painful, and it's the problem that all these multitudinous programming "async" techniques are trying to get around. Promises, for instance, can be looked at as a partial way of having a sort of stack around a particular sequence of operations that may be interrupted in arbitrary locations by this event-induced stack discarding. In this sense they can also be viewed as an inner-platform problem; where the language has "try/catch", for loops, etc, promises end up trying to recreate all that in a second layer above the bottom layer, with all the corresponding complexity of embedding a language in the language. If you then end up asking, "Well, what if we just didn't discard the stack in the first place?", you end up in Erlang/Go/Haskell/Scala land.
Nemcue 11y ago
It's extra funny because without stiching together stack traces you lose the stack by using A+ Promises.

hahahahaha this one cracked me up "Writing code without a stack is a lot like driving a car without a brake pedal: you don't realize how badly you need it, until you reach for it and it's not there."

Kenji 11y ago

I didn't really understand that one. First of all, I don't see why a stack really is that indispensable, and secondly, JavaScript does actually have a stack so I don't know how he thinks it's operating stackless - where do the local variables go?

nolanl 11y ago
This is what I mean: doSomething(function (err) { doSomethingElse(function (err) { doYetAnotherThing(function (err) { throw new Error( "I don't bubble up to the top of the stack, " + "because there is no stack!"); }); }); }); BTW a great trick is to tick the little "Async" box in the Chrome Dev Tools, so you can get a full stacktrace showing exactly where you came from. It works for both callbacks and promises: http://www.html5rocks.com/en/tutorials/developertools/async-call-stack/ http://www.html5rocks.com/en/tutorials/developertools/async-...
jerf 11y ago
In the classic, but widely misunderstood, "Goto Considered Harmful", Dijkstra's point is basically that structure programming is good because it produces a stack and an instruction pointer, which contains an immense quantity of useful information when a crash occurs. Goto is bad in this paper because when it is used as the only control flow construct, in a way difficult for a modern programmer to understand in a world where structured programming won so thoroughly that every language is structured, it produces no stack trace. You get a "Crash On Line 28430", with no clue how you got there. Naive event-based code is somewhat like a goto, in that every time an event comes in, you get a new stack constructed for that event. While you then get a stack if you call functions from the initial handler, every event that comes in whacks the stack afresh. So it isn't "the same as" a goto, but it does hurt the stack. Instead of a stack frame that represents the whole of the program, you get a series of "island" stack frames. In some sense, this is the most fundamental reason why event-based programming is so painful, and it's the problem that all these multitudinous programming "async" techniques are trying to get around. Promises, for instance, can be looked at as a partial way of having a sort of stack around a particular sequence of operations that may be interrupted in arbitrary locations by this event-induced stack discarding. In this sense they can also be viewed as an inner-platform problem; where the language has "try/catch", for loops, etc, promises end up trying to recreate all that in a second layer above the bottom layer, with all the corresponding complexity of embedding a language in the language. If you then end up asking, "Well, what if we just didn't discard the stack in the first place?", you end up in Erlang/Go/Haskell/Scala land.

Nemcue 11y ago

It's extra funny because without stiching together stack traces you lose the stack by using A+ Promises.