Menu
Julia has an interesting support for Unicode characters. The syntax allows me to run the following in the iJulia notebook.
μ = 10
σ = 20
∑ = sum
a = [1,2,3,4]
∑(a) # prints 10
However, it doesn't always seem like you can use Unicode characters for function/variable names.
√ = sqrt
Gives the following error:
syntax: unexpected "="
forall(x,f) = [f(i) for i in x]
∀ = forall
Gives the following error:
syntax: invalid character "∀"
Am I misunderstand the rules? I assumed that a Unicode character would be interpreted just like any other alphabetical character, but I seem to get two different errors on seemingly simple statements.
892
Inserting Unicode characters To insert a Unicode character, type the character code, press ALT, and then press X. For example, to type a dollar symbol ($), type 0024, press ALT, and then press X.
Inserting Unicode CharactersType the character code where you want to insert the Unicode symbol. Press ALT+X to convert the code to the symbol. If you're placing your Unicode character immediately after another character, select just the code before pressing ALT+X.
The Unicode character encoding standard is a fixed-length, character encoding scheme that includes characters from almost all of the living languages of the world. Information about Unicode can be found in The Unicode Standard , and from the Unicode Consortium website at www.unicode.org.
In Python, the built-in functions chr() and ord() are used to convert between Unicode code points and characters. A character can also be represented by writing a hexadecimal Unicode code point with \x , \u , or \U in a string literal.
√ is the name of an existing function; try running the following:
julia> methods(√)
# 12 methods for generic function "sqrt":
sqrt(a::Complex{Float16}) at float16.jl:141
sqrt{T<:FloatingPoint}(z::Complex{T<:FloatingPoint}) at complex.jl:237
sqrt(z::Complex{T<:Real}) at complex.jl:261
...
As for ∀, it is not a valid character in Julia source code (yet?). See this discussion; what transpires is that the developers are still considering whether to make ∀ a valid character, and if they do, what meaning it would have.
84
I think the problem is that these functions are already defined.
See the link some of the characters that have meanings built into Julia: https://github.com/JuliaLang/julia/blob/d234b4ff56df9ce85198dcdd8d9ef1073b2436fc/base/operators.jl#L403-L432 (note, not all of these are unicode and there might be others in a different file in base -- but this at least covers your sqrt example)
20
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
