Mathematical operators and symbols support

[k0001]

Modern markup languages such as MathML, or programming languages such as Agda, Haskell and Scala can make extensive use of the Greek alphabet and mathematical symbols. Users of these languages could benefit from Source Code Pro if these characters were supported. In particular Agda and MathML make the most extensive use of Unicode, by design.

Issue #48 already requests Greek alphabet support.

Here are some quite comprehensive list of mathematical symbols:

• MathML 2.0: Characters, Entities and Fonts (W3C): http://www.w3.org/TR/MathML2/chapter6.html
• Unicode Entity Codes for Math (PSU): http://archive.tlt.psu.edu/suggestions/international/bylanguage/mathchart.html
• Mathematical operators and symbols in Unicode (Wikipedia): http://en.wikipedia.org/wiki/Mathematical_operators_and_symbols_in_Unicode

Here are some code snippets and blog posts making use of this feature:

• http://www.w3.org/TR/MathML2/chapter6.html
• http://code.haskell.org/Agda/examples/SimpleTypes.agda
• http://code.haskell.org/Agda/examples/Introduction/Unicode.agda
• http://scalaz.github.com/scalaz/scalaz-2.9.0-1-6.0.1/doc.sxr/scalaz/MA.scala.html
• http://conal.net/blog/posts/a-third-view-on-trees

[k0001]

I'd like to add that fonts such as DejaVu Sans Mono or FreeMono already support a wide variety of such mathematical symbols, operators, and letters.

[pauldhunt]

I am planning on adding Greek at some point, but I had no plans to add these. I would definitely need some help creating all of these.

[k0001]

Greek support will be excellent.

Certainly, this is hard work. In any case, maybe it can be helpful to start by prioritizing some of these symbols according to how often they are used, so I'll try that:

In this list http://archive.tlt.psu.edu/suggestions/international/bylanguage/mathchart.html#set I've often came across symbols in these categories:

• Letter Symbols
• Logic & Set Theory
• Common Statistics
• Common Symbols
• Calculus
• Geometric Symbols (Tacks)
• Logical Proofs
• Common Equivalence Operators
• Other mathematical symbols (∓ ∗ ∘ ∙ ∶ ∷ ≔ ≟ ≺ ≻ ⊓ ⊔ ⊕ ⊖ ⊗ ⊙ ⊛ ⊝ ⋅)

[pauldhunt]

Can you give Unicode ranges/code points for these?

[k0001]

Yes. Thanks for asking that.

It seems that the most common mathematical symbols are, unsurprisingly,
in the Mathematical Operators block: U+2200–U+22FF.

There are some letter-like symbols, however, that fall outside that
block:

• ℵ → U+2135
• ℘ → U+2118
• ℑ → U+2111
• ℜ → U+211C
• ℝ → U+211D
• ℂ → U+2102
• ℕ → U+2115
• ℙ → U+2119
• ℚ → U+211A
• ℤ → U+2124

[jfim]

Specifically for the Scala programming language, the rightwards double arrow (U+21D2 ⇒) is part of the language specification, so it would be awesome to have it. The leftwards single arrow (U+2190 ←) is already in the font and looks great!

[pauldhunt]

@jfim that’s easy, i’ll sneak that in there.

[jfim]

Sweet, can't wait to get rid of the horrid fallback font arrows! :)

[andy-morris]

@pauldhunt Hooray! Mono fonts always seem to have ←/→ but never ⇐/⇒. (Haskell uses ⇒ with the UnicodeSyntax option as well, fwiw.) So a font that actually has them would be a nice change. :)

[adrientetar]

The Hasklig font has some arrows that could be checked-in upstream.

[miguelsousa]

The Powerline glyphs may be a good addition since there's an open request (#43). The other glyphs not so much because the set of arrows is very incomplete.

[valpackett]

Any progress on this? (Especially ∷ ⇒ →)

[pauldhunt]

I am actively working on the next revision of the SCP fonts and plan to add these characters. the single arrow is already in the font, so you’re jus looking for the double stroked arrow and the proportion symbol (u+2237)? is that correct?

[andy-morris]

If you wouldn't mind adding ∀ and ∃ too, that'd be even better. But at least a mono font with a non-ugly ⇒ would be great.

(btw: Hasklig doesn't play nice with GUI vims because it lays out the characters on a grid.)

[pauldhunt]

I’ve gone and added u+21D2, u+2200, u+2203, u+2237 to the design masters and these will make it into the next version of the released upright fonts.