![]() I think the first more naturally expresses the desired algorithm.Python Tutorial Python Features Python History Python Applications Python Install Python Example Python Variables Python Data Types Python Keywords Python Literals Python Operators Python Comments Python If else Python Loops Python For Loop Python While Loop Python Break Python Continue Python Pass Python Strings Python Lists Python Tuples Python List Vs Tuple Python Sets Python Dictionary Python Functions Python Built-in Functions Python Lambda Functions Python Files I/O Python Modules Python Exceptions Python Date Python Regex Python Sending Email Read CSV File Write CSV File Read Excel File Write Excel File Python Assert Python List Comprehension Python Collection Module Python Math Module Python OS Module Python Random Module Python Statistics Module Python Sys Module Python IDEs Python Arrays Command Line Arguments Python Magic Method Python Stack & Queue PySpark MLlib Python Decorator Python Generators Web Scraping Using Python Python JSON Python Itertools Python Multiprocessing How to Calculate Distance between Two Points using GEOPY Gmail API in Python How to Plot the Google Map using folium package in Python Grid Search in Python Python High Order Function nsetools in Python Python program to find the nth Fibonacci Number Python OpenCV object detection Python SimpleImputer module Second Largest Number in Python $b = new Builder() // class Builder is annotated as 18:31 GMT, Larry Garfield is when you only allow one reference to an object (or In concept, maybe? That's well above my pay grade. $foo = clone $foo with to $foo->x = 42, even if the clone is I wonder if that difference can be optimised out by theĬompiler/OpCache: detect clones that immediately replace their original,Īnd optimise it to an in-place modification. To avoid accidentally mutating the speed of light: To put it a different way, value types naturally form expressions, Therefore natural to want the same for a range of dates: I think the first more naturally expresses the desired algorithm. $end += 5 // where += would be an in-place modification, not a If integers were mutable but not aliasable, we This models integers as immutable values, and + as an operator which ![]() "withX" methods are actually more natural than explicitly cloningĬonsider the case of defining a range: firstly, with plain integers and However, from a high-level user-friendliness point of view, I think Thanks, I can see how that solves a lot of the same problems, in a very I would like to add an annotation to Psalm, like this is also needed to make type-state sane. Haskell is also related (but is both more complex and more powerful). Uniqueness (I need to read up more on it, tho). It can take a looong time to force new concepts like these into commonĭiscourse. System merits some attention, not ONLY immutability. BUT with immutability, you have to copy $b The guarantee in both above snippets is that myfun() DOES NOT modify Myfun(clone $b) // HAVE TO CLONE TO NOT THROW EXCEPTION. $b = new Builder() // class Builder is annotated as non-aliasing/unique ![]() Myfun($b) // $b is immutable, so $b cannot be modified by myfun() You can compare a builder pattern with immutability vs non-aliasing This performance gain matters in PHP programs). Since it leads to less memory copy (but of course it's not certain Uniqueness has the benefit of being more performant than immutability, Universe Types, but let's ignore that for now. The are more advanced systems of ownership than just uniqueness, e.g. Language like PHP): Spooky action at a distance, fragile composition, Uniqueness and immutability solves similar problems (at least in a GC $b = $a // Both $a and $b point to the same place in memory, so you Uniqueness is when you only allow one reference to an object (or Could you clarify, perhaps with some examples? I'm afraid I don't follow what you mean by "non-aliasing" and 21:36 GMT, Rowan Tommins just want to mention that immutability might be applied too Rather uniqueness, at least in some cases. I think methods like withX is an anti-pattern, inįact, and a symptom that you do not really want immutability, but Want is non-aliasing, that is, uniqueness, to solve problems related ![]() Liberally in the current discourse, and in some cases, what you really I just want to mention that immutability might be applied too (probably because it never went into a final RFC) Is there a reason you didn't mention the proposal for immutable classes? The full writeup is hope it proves stimulating, at least of discussion and not naps. Of the various things that have been floated about recently. Well-received in the past, I decided to do a complete analysis and context 8:26 GMT, Marc been a number of discussions of late around property visibilityĪnd how to make objects more immutable. ![]()
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