Changes to pldb.io

+ hasStaticTyping false

+ hasStaticTyping true

+ hasStaticTyping true

+ hasStaticTyping true

+ hasStaticTyping true

+ hasStaticTyping false

+ hasStaticTyping true

+ hasStaticTyping true

+ hasTypeAnnotations true

+ name: str

+ hasStaticTyping true

+ # Optional, checkable using external type checkers like Mypy or Pyright

+ def print_repeated(text: str, repetitions: int) -> None:

+ print("\n".join([text]*repetitions))

+

+ print_repeated("Hello!", 10)

+ print_repeated("This won't typecheck...", "not an integer")

+ hasStaticTyping true

+ hasStaticTyping true

+ creators Doug Lenat

+ hasStructuralTypingParser

+ extends abstractFeatureParser

+ description Does the language feature (significant) structural typing?

+ string title Structural Typing

+ string reference https://en.wikipedia.org/wiki/Structural_type_system

+

+ hasStructuralTyping false

+ hasStructuralTyping false

+ hasStructuralTyping true

+ // concepts use structural typing:

+ // NOTE that concept implementations MUST be defined BEFORE the concept itself

+ hasTypeClasses false

+ hasStructuralTyping false

+ https://stackoverflow.com/q/44484287

+ hasStructuralTyping false

+ hasStructuralTyping false

+ https://youtrack.jetbrains.com/issue/KT-218

+ hasStructuralTyping true

+ hasStructuralTyping true

+ # Python's optional static type system features 2 kinds of structural types:

+ from typing import Protocol

+

+ class Clearable(Protocol):

+ def clear(self): ...

+

+ def print_and_clear(x: Clearable):

+ print(x)

+ x.clear()

+

+ print_and_clear([1, 2, 3]) # OK because lists have a clear() method

+ print_and_clear({1, 2, 3}) # OK because sets have a clear() method

+ print_and_clear(1) # not OK because ints don't have a clear() method

+

+ from typing import TypedDict

+

+ class NameDict(TypedDict):

+ first_name: str

+ last_name: str

+

+ class EmployeeDict(TypedDict):

+ employee_id: int

+ first_name: str

+ last_name: str

+

+ def greet(name: NameDict):

+ print(f"Hello {name['first_name']} {name['last_name']}!")

+

+ john: EmployeeDict = {

+ "first_name": "John", "last_name": "Smith", "employee_id": 123

+ }

+

+ # EmployeeDict is a (structural) subtype of NameDict even though there is no

+ # explicit relation between them, so this passes type checking:

+ greet(john)

+ hasStructuralTyping false

+ tuples can be seen as structural, [1] but other fundamental types like structs

+ and traits are not structural and don't have structural analogues

+

+ [1]: https://doc.rust-lang.org/reference/types/tuple.html

+ hasStructuralTyping true

+ // https://docs.scala-lang.org/scala3/reference/changed-features/structural-types.html#using-java-reflection-1

+ import scala.reflect.Selectable.reflectiveSelectable

+

+ type Reversable[T] = { def reverse: T }

+

+ def printReversed[T](x: Reversable[T]): Unit = {

+ println(x.reverse)

+ }

+

+ printReversed("abc")

+ printReversed(Array(1, 2, 3))

+ printReversed(1) // Doesn't compile because integers don't have a reverse method

+ hasStructuralTyping true

+ // https://www.typescriptlang.org/docs/handbook/type-compatibility.html

+ // Subtype relations are structural for both interfaces and classes.

+ // Interface example:

+ interface CanCheckIncludes {

+ includes(x: T): boolean;

+ }

+

+ function logIfIncludes(includer: CanCheckIncludes, includee: T) {

+ if (includer.includes(includee)) {

+ console.log(includer);

+ }

+ }

+

+ logIfIncludes("abc", "b");

+ logIfIncludes([1, 2, 3], 4);

+ logIfIncludes(1, 1); // Fails typechecking, as numbers don't have includes()

+ hasFunctionOverloading false

+ website https://www.curry-lang.org/

+ webRepl https://smap.curry-lang.org/smap.cgi?upload?lang=Curry&program=%2D%2D+Returns+the+last+number+of+a+list%2E%0Alast+%3A%3A+%5BInt%5D+%2D%3E+Int%0Alast+%28%5F+%2B%2B+%5Bx%5D%29+%3D+x%0A%0A%2D%2D+Returns+some+permutation+of+a+list%2E%0Aperm+%3A%3A+%5Ba%5D+%2D%3E+%5Ba%5D%0Aperm+%5B%5D+++++%3D+%5B%5D%0Aperm+%28x%3Axs%29+%3D+insert+%28perm+xs%29%0A+where+insert+ys+++++%3D+x+%3A+ys%0A+++++++insert+%28y%3Ays%29+%3D+y+%3A+insert+ys%0A+++++++%0Amain+%3D+perm+%22XYZ%22

+ description Curry is a declarative multi-paradigm programming language which combines in a seamless way features from functional programming (nested expressions, higher-order functions, strong typing, lazy evaluation) and logic programming (non-determinism, built-in search, free variables, partial data structures). Compared to the single programming paradigms, Curry provides additional features, like optimal evaluation for logic-oriented computations and flexible, non-deterministic pattern matching with user-defined functions.

+ emailList https://www.curry-lang.org/various/mailinglist/

+ webRepl https://live.lean-lang.org/

+ hasNamedArgumentsParser

+ extends abstractFeatureParser

+ description Does the language have named arguments / named parameters?

+ string title Named Arguments

+ string reference https://en.wikipedia.org/wiki/Named_parameter

+

+ hasFunctionOverloading false

+ hasNamedArguments false

+ hasFunctions true

+ hasFunctionOverloading false

+ hasNamedArguments false

+ hasNamedArguments false

+ hasFunctions true

+ hasFunctionOverloading TODO

+ hasNamedArguments false

+ hasFunctions true

+ TODO

+ hasFunctionOverloading true

+ hasNamedArguments false

+ hasNamedArguments false

+ // idiomatically emulated using parameters that expect objects

+ hasFunctionOverloading true

+ hasNamedArguments true

+ "abcdef".subSequence(startIndex=2, endIndex=4)

+ hasFunctionOverloading false

+ may be simulated using `**kwargs` or `functools.singledispatch`

+ hasNamedArguments true

+ print("Hello", end="!\n")

+

+ # details: any parameter that hasn't been explicitly marked as positional-only

+ # can be provided as a named argument

+ hasNamedArguments true

+ String.new("abc", encoding: "utf-8", capacity: 16)

+

+ # details: when defining a method, parameters are positional-only by default,

+ # but can be made keyword parameters (i.e. named) by appending a colon (:),

+ # optionally followed by a default value:

+ def greet(name, time_of_day:, location: "our great city")

+ puts "Hello this fine #{time_of_day} in #{location}, #{name}!"

+ end

+ hasFunctions true

+ hasFunctionOverloading false

+ hasNamedArguments false

+ hasFunctionOverloading false

+ hasNamedArguments true

+ "abcdef".slice(from=2, until=4)

+ hasNamedArguments false

+ // idiomatically emulated using parameters that expect objects

+ atoms measureNameAtom tagAtom

+ (lambda (exp env cont)

+ (cond ((eq? (car exp) 'instr)

+ (eval-instr (car (cdr exp)) env cont))

+ (else

+ (original-eval-application exp env cont))))))

+

+ example

+ [drs([A, B, C],

+ [theta(A, theme, C)#[1],

+ event(A, working)#[1],

+ theta(A, location, B)#[1],

+ named(B, macquarie university)#[1, [third, sg, neut],

+ [’Macquarie’,’University’]],

+ named(C, david miller)#[1, [third, sg, masc],[’David’,’Miller’]]])]