In many modern languages, a function is just a specific kind of value that happens to be callable. However, some languages, even if they support first-class functions, assign functions to their own namespace separate from values.
In Common Lisp, functions and values occupy different namespaces. A...
I'm in the process of designing a simple domain-specific language and I think that a term-rewriting system may provide the simplest way to specify and implement it. However, I have only seen a few examples of term-rewriting systems, so I don't have much sense for the possibilities of how you can ...
Long ago, I got an error message in Scala informing me that I had a GADT skolem. I googled but only found very abstract descriptions of GADT skolems, nothing with an example that illustrated in a realistic context why the concept is needed. I found a workaround to the error but never understood w...
In Prefix notation, the operator comes before the operands (e.g., +a b).
In Postfix notation, the operator comes after the operands (e.g., a b+).
In Infix notation, the operator comes in between the operands (e.g., a+b).
Most practical languages use infix notation, but some esoteric languages u...
Compiling and interpreting programming languages typically involves parsing text into a tree that represents the different groupings of syntactic elements. The hierarchy represents which syntactic elements a program has but in data structure form instead of string form. A very basic example would...
I am sure that asking a question such as 'What should I name my programming language' is going to be too broad and opinion-based. But if someone had a more specific question about naming a programming language such as 'Is too similar to any existing programming languages?' could such questions b...
This is not possible under iOS. You only can send push notifications to a specific (your own) app.
This language is implemented in Rust using a lot of enums for things like expressions. Some of the planned validation rules involve checking how parenthesis are used -- where they're needed and are not, for example. This is currently done with an Expr::Parenthesized node. However, I want to be ab...
How might one go about building a parser that can distinguish custom operators in prefix, infix or postfix positions.
For example:
# Hypothetical operator
@postfix(Precedence.Not)
let ~ = fn(a) = ...
@infixleft(Precedence.Addition)
let ~^ = fn(a, b) = ...
@prefix(Precedence.Not)
let ^ = fn(a) ...
When implementing Unicode identifiers, I'm never sure what characters should be allowed. For example, this is the list of categories:
Control: C
Letters: L
Marks: M
Numbers: N
Punctuation: P
Symbols: S
Whitespace: Z
Each of these have different subcategories. What's a sensible policy for what U...
As some examples of standard queue types:
C++ has deque (queue is just a wrapper around it), which is typically implemented as a doubly-linked list of arrays.
C# has Queue, which uses a resizable circular buffer.
Swift doesn't officially have a queue type, but some standard library algorithms th...
The project that I worked on for some months is Kind It's a dependently typed language that implements some type of "spartan type theory" with Type in Type. The type checker works by joining the source code of the Type checker with a HOAS representation of the code that it wants to type check som...
I want to have some performance on my language but with more powerful types. At the beginning I thought a lot about just going straight forward with a Hindley-Milner and perform monomorfization but I have not reached a conclusion about what kind of type checker I need to have in order to make a l...
For example:
Java uses a toString() method, and calls that behind the scenes. If you don't implement one, you inherit it from the base class (Object).
JavaScript uses the ToPrimitive abstract operation, which involves @@toPrimitive, "toString", and "valueOf". You can read the spcification here. ...
What are the most common ways of compiling code of a language with first-class support for exceptions, such as C++? Panics in Rust, which have similar behavior, shouldn't be different.
From my experience, "local jumps" such as continue or break doesn't seem too hard. The problem with exception ap...
Say I have a list class which has a sort method.
class List { // the standard library list class for a language
// ...
method sort {/*...*/}
// ...
}
Should this method, when called, sort the list in-place or return a new sorted list? I don't know which is more efficient and which i...
In several functional languages like Haskell and OCaml, functions are automatically curried. But most programming languages, even many functional languages, like Elixir, don't do this.
What are the advantages and disadvantages of this approach to functions?
