The Periodic Table of Rust Types

http://cosmic.mearie.org/2014/01/periodic-table-of-rust-types/

by lifthrasiir • 13 years ago

150 71 13 years ago

cosmic.mearie.org

carterschonwald• 13 years ago

I think this a great way of presenting type features that interact! props to the author for cooking it up

_pmf_• 13 years ago

I think this a great way of presenting type features that interact! props to the author for cooking it up

It's a great way to present it, but like Scala's infamous "Periodic Table of Dispatch Operators", stuff like is rather off putting. Why use crude sigils when you could just as well use easily understood keywords (like ref, out, unsafe etc. in C-Sharp)?

Ygg23• 13 years ago

Funny enough, ~ sigil will probably be retiring in favor of box.

    let x = ~"Thing"; //old code
    let x = box Thing // new code probably

Note: I said probably because it's probably because:

A) Not sure it will be implemented

B) Not sure if that will be syntax

--- PS. Any link to dispatch operator periodic table?

Also I take your scala and raise you a Perl: http://glyphic.s3.amazonaws.com/ozone/mark/periodic/Periodic...

andolanra• 13 years ago

It's nice to have very common features be syntactically lightweight, and sigils are incredibly lightweight compared to two-or-three character keywords. Rust code uses these pointers in all but the most trivial code, so they'll be showing up a lot; in contrast, I suspect as a non-C# programmer that ref and out are not as widely used in most C# codebases as ~ and & are in Rust. There are also not that many sigils, all told—three sigils for pointers plus a few other operators that appear in this table.

Additionally, this table is different from the tables of Scala dispatch operators, Perl operators, &c because of its regularity—it has two axes and a good deal of the information presented is a straightforward function of a cell's position in the table[1]. For example, the entry in the Owned column and the String row is going to be an... owned string, which is going to be prefixed with ~ (like every cell in the Owned column) and have a base type of str (like every cell in the String row). This is a far cry from the table of Scala's dispatch operators, in which there's no consistent indication of what a given operator will necessarily do aside from a general grouping of like operators.

[^1, edit]: That isn't to say that ALL the information is a (predictable) function of a cell's position in the table. Some of that irregularity comes from arguably expected consequences of Rust semantics (e.g. of course you can't have a bare string, because you can only have bare values whose sizes are known in advance, and you don't know how long a string will be) while some is genuinely arbitrary, like the syntactic sugar for functions.

dnautics2• 13 years ago

can we just make it "table"? There are no periodic trends that I can see.

Dewie• 13 years ago

http://glyphic.s3.amazonaws.com/ozone/mark/periodic/Periodic...

lifthrasiir3• 13 years ago

That was my direct inspiration, though I suck at graphics design. Fortunately the periodic table of Rust types was much concise than that of Perl 6 operators...

dbaupp5• 13 years ago

There are some trends. Types to the right are "subsets" of types to the left; e.g. a &mut T can coerce to a &T, similarly, you can box a T into a ~T, or take references to get an &mut T or &T.

dnautics2• 13 years ago

periodicity refers to (originally) that the trends are cyclical with respect to atomic mass - we now know that it's with respect to atomic number and that the period increases (2 - 8 - 18 - much more) but nonetheless between multiple rows there's an increasing valence. Hence there is a repeating aspect 'period' driven by a connection between row n and n+1 (row n+1 immediately follows row n in atomic number). There's no connection between row n and row n+1 in this table of rust types. The vertical organization is completely arbitrary, there is no ascending value across the table, and therefore it's not periodic.

TylerE5• 13 years ago

This all seems like a mis-feature. Smells of C++.

lifthrasiir3• 13 years ago

You can make a similar table with C++, complete with pointer, pointer-to-member, function pointer, member function pointer, reference, r-value reference, array, std::auto_ptr, std::unique_ptr, std::shared_ptr, const and volatile. :)

hdevalence2• 13 years ago

Except C++ doesn't have, for instance, a way to mark data as immutable, so the table's going to be a bit lacking...

bascule• 13 years ago

It's actually correcting the mistakes of C++:

- Ownership: means no unsafely shared mutable state, checked at compile time with no runtime overhead. Also, no explicit deallocations!

- A real type system: Rust's type system is inspired by the Hindley-Milner type inference algorithm used in languages like ML and Haskell

TylerE5• 13 years ago

The thing is I've used lots of languages with full H-M inference that are much less complicated than this.

pcwalton6• 13 years ago

Could you elaborate as to what you'd prefer instead?

TylerE5• 13 years ago

A simpler language.

danellis• 13 years ago

Perhaps more words and fewer symbols.

Ygg23• 13 years ago

Don't forget there are two types of languages:

1. Languages that people moan about

2. Languages that people don't use

I'd love if magical syntax fairy would make Rust easy to read as Python, but I think the complexity fits the domain. Safe manual memory handling is probably gonna look weird because of guarantees it must make.

noelwelsh2• 13 years ago

This is great, and just what I needed to organise Rust types systems in my head. This should definitely be a part of the official documentation.

didgeoridoo• 13 years ago

Aww, I thought this was going to be a table of metal oxides and their chemical & physical properties.

luckyno13• 13 years ago

Haha you aren't alone on that one.

kps• 13 years ago

Ah, you're looking for Hacksaw News.

So… would a dialect of Ruby without side effects be called Corundum?

mcguire2• 13 years ago

Structure types?

steveklabnik3• 13 years ago

They're of type T.

The Periodic Table of Rust Types

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