Why does Julia use begin/end as the block delimiter instead of the more common and concise { }? Why is that better?

[image] jar1: This seems a likely explanation given Matlab’s end syntax (though I don’t see a begin there). There’s another thing I forgot: in the early days of Julia, {a; b; c} and {a, b, c} were syntax for what is now Any[a; b; c] or Any[a, b, c], e.g. in Julia 0.3: julia> {3,4,5} 3-elemen…

{} is used for types. Also end can end any of let, for, while, if, function, struct, module etc. so it means an opening { can be skipped. After all, it’s just for ... end, not for begin ... end

That means built-in blocks are easier than user-defined blocks, which I consider bad not good. Still {} is shorter than end anyway.

At this point I’m just looking for an explanation of why it is this way.

Parameterized types are used heavily in Julia, and are often deeply nested ala Dict{Int,Vector{Complex{Float64}}}, so a compact (single-character bracket) ASCII symbol was crucial, and there aren’t many to choose from. (C++ was forced to choose <...> and it’s a mess for nesting because < and << are…

Thanks. I think something is missing from this explanation though. [image] stevengj: Parameterized types are used heavily in Julia, and are often deeply nested ala Dict{Int,Vector{Complex{Float64}}}, so a compact (single-character bracket) ASCII symbol was crucial, and there aren’t many to choo…

[image] jar1: Why is that better? I don’t recall seeing claims that this is better, it is merely different. I can’t say whether the devs were influenced by Python, but that’s another language that has rethought syntax and freed up curly braces for other things. If you stick around long enough…

[image] stevengj: Now, we are free to to use {a; b; c} for a really cool new feature (if we can think of one) See also: Free up curly brace syntax. JuliaLang:master ← JuliaLang:jcb/rmanyarray …

If you want, you can use braces as block in macros. macro b(expr) expr.head == :bracescat || error("invalid block syntax, must write @b {...}") expr.head = :block esc(expr) end @b { x = 1 + 1 y = 3 + 4 x + y } function in_to_eq(ex::Expr) if ex.head == :call && ex.args[…

[image] jar1: This seems a likely explanation given Matlab’s end syntax (though I don’t see a begin there). Ruby and Lua both have end blocks btw, so it’s hardly a weird choice for Julia

Why begin/end instead of { } for block delimiter

Internals & Design

adienes November 3, 2022, 8:35pm 4

Unfortunately, Julia is not at that stage of development anymore. I hope this minor syntax choice will not be a blocker for you to explore the language.

Topic		Replies	Views
Syntax suggestion: end<control> Internals & Design	53	3805	October 17, 2018
Keeping the syntax and the need to memorise syntax simple Internals & Design	100	8116	September 7, 2022
Julia included in Oreilly's "Emerging Programming Languages" report (June 2019) Community	52	3381	June 26, 2019
Why does Julia have multiple ways to define functions? New to Julia question	24	2802	October 16, 2024
A most harrowing collection of Julia WATs General Usage wat	108	12789	January 27, 2024

Why begin/end instead of { } for block delimiter

Related topics