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Comment by nightpool | Hacker News Reader

JS also doesn't have TCE, but for Python even just the lambda limitations are surprisingly annoying. I can't tell you how many times i've been frustrated because it's nearly impossible to put a print statement into a python lambda

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As a Python enjoyer, why do we want to shove so much into lambdas rather than just doing an inline function `def`?

Is it the fact that you have to give it a name? If so I'd say just using some generic name like `{f,fn,func(tion),callback,etc}` is fine (at least as much as an anonymous function is), and to me would usually be more readable than an inline definition of a multi-statement lambda would be.

Or maybe it's the fact that lambdas are allowed in the first place, so people are going to use them, and then when you want to debug a lambda you'll probably have to go to the trouble of changing it to a function? That is a fair complaint if so.

In any case I can see how it could be annoying if you're more used to a language full of complex inline lambdas.

JS also kills Python for inline functions thanks to hoisting.

It's much easier to follow the control flow with hoisting. I see `run()` being called, and then I want to know what it is. In other languages you are usually seeing a huge bunch of inline functions and then asking: okay, but when and how is this actually called?

    def foo():
      def run():
        print("hi")
      run()

    function foo() {
      run()
      function run() {
        console.log('hi')
      }
    }

honestly I don't like this style of writing... in your js example I see `run()` and my first though is where the hell is run defined? is a global? I don't search - nor I write - the called function AFTER the calling ones, it seems backward to me.

moreover... basically any half-decent programmer text editor has an outline with the list of functions, so this point may be moot in any way

Lambda is quite clunky. A lot is possible by abusing tuples and walrus assignment, which Ive on occasion used for one liners. e.g. you want to execute a function for each element of a list (print is a function in py3) so mapping over a generator with eg

    map(lambda x: (x := func1(x), func2(x), None)[2], gen())

This sets x to func1(x), then executes func2, then leaves None in place of the element in the map iterable. (of course you could do the same with a list comprehension, you wouldn't even need the lambda in that case, and good python would _actually_ be a for loop.)

That's a mismatch between Python's choice of lambda syntax and the use of whitespace instead of curly braces.

lambda x: print(x) or x

JS technically does have TCE (specified in ES6[1]), but only the JavaScriptCore runtime used by Safari/WebKit implements it[2].

[1]: https://webkit.org/blog/6240/ecmascript-6-proper-tail-calls-... [2]: https://kangax.github.io/compat-table/es6/#test-proper_tail_...

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