> It wouldn't necessarily break existing API, since
String.prototype.replace currently accepts only RegExp or strings.
Not quite accurate. It accepts anything with a `Symbol.replace` property,
or a string.
Given that, what you're describing can be implemented as
```
Map.prototype[Symbol.replace] = function(str) {
for(const [key, value] of this) {
str = str.replace(key, value);
}
return str;
};
```
> I don't know if the ECMAScript spec mandates preserving a particular
order to a Map's elements.
It does, so you're good there.
> Detecting collisions between matching regular expressions or strings.
I think this would be my primary concern, but no so much ordering as
expectations. Like if you did
```
"1".replace(new Map([
['1', '2'],
['2', '3],
]);
```
is the result `2` or `3`? `3` seems surprising to me, at least in the
general sense, because there was no `2` in the original input, but it's
also hard to see how you'd spec the behavior to avoid that if general regex
replacement is supported.
On Fri, May 18, 2018 at 9:47 AM, Alex Vincent <[email protected]> wrote:
> Reading [1] in the digests, I think there might actually be an API
> improvement that is doable.
>
> Suppose the String.prototype.replace API allowed passing in a single
> argument, a Map instance where the keys were strings or regular expressions
> and the values were replacement strings or functions.
>
> Advantages:
> * Shorthand - instead of writing str.replace(a, b).replace(c,
> d).replace(e, f)... you get str.replace(regExpMap)
> * Reusable - the same regular expression/string map could be used for
> several strings (assuming of course the user didn't just abstract the call
> into a separate function)
> * Modifiable on demand - developers could easily add new regular
> expression matches to the map object, or remove them
> * It wouldn't necessarily break existing API, since
> String.prototype.replace currently accepts only RegExp or strings.
>
> Disadvantages / reasons not to do it:
> * Detecting collisions between matching regular expressions or strings.
> If two regular expressions match the same string, or a regular expression
> and a search string match, the expected results may vary because a Map's
> elements might not be consistently ordered. I don't know if the ECMAScript
> spec mandates preserving a particular order to a Map's elements.
> - if we preserve the same chaining capability
> (str.replace(map1).replace(map2)...),
> this might not be a big problem.
>
> The question is, how often do people chain replace calls together?
>
> * It's not particularly hard to chain several replace calls together.
> It's just verbose, which might not be a high enough burden to overcome for
> adding API.
>
> That's my two cents for the day. Thoughts?
>
> [1] https://esdiscuss.org/topic/adding-map-directly-to-string-prototype
>
> --
> "The first step in confirming there is a bug in someone else's work is
> confirming there are no bugs in your own."
> -- Alexander J. Vincent, June 30, 2001
>
> _______________________________________________
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> [email protected]
> https://mail.mozilla.org/listinfo/es-discuss
>
>
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