[Thrall]

I sometimes wonder why languages use sequences like "->". This is clearly meant to represent an arrow, so why has noone ever taken the time to make sure an arrow character is defined, make sure it's possible to type it in most keyboard maps and use it in programming languages.

It can't be because physical keyboards wouldn't have the key, because my keyboard doesn't display a # symbol, but that is widely used.

I can only guess that the character sets and "what characters are easy to type into a computer" became standardised early on, and no individual language has been able to push such a change (Early in development a language has few users, thus no influence; Later in development, the language has been using "->" itself for a while, so it's less easy to change).

Also, proper languages like lisp use parentheses (), not curly braces. :p

[kps]

Several early programming systems did use custom character sets (custom type bars) as well as typewriter-oriented notations like overstrikes, half-line motions for superscripts (powers) and subscripts (indexes), and colour (red half of the ribbon for comments)¹. Except for APL, which had IBM behind it, these tended not to escape their original research environments.

Relatively large-scale production required I/O devices to share a common character set. These tended to be based on pre-computer character sets (teletypes, punched cards) and were limited in size both by the I/O devices and by storage requirements (don't forget how small and expensive memories were). A lot of work went into choosing character sets.²³⁴

1963 ASCII had an up arrow ‘↑’ dropped in 1967 in favour of ^ (because furriners wanted accents), and a left arrow ‘←’ dropped in favour of ‘_’.⁵⁶

¹Jean Sammet, Programming Languages: History and Fundamentals 978-0137299881
 ²Charles E. MacKenzie, Coded Character Sets: History and Development 978-0201144604
 ³http://www.trailing-edge.com/~bobbemer/SURVEY.HTM ⁴R W Bemer, Design of an improved transmission/data processing code http://dx.doi.org/10.1145/366532.366538
 ⁵American Standard Code for Information Interchange http://www.wps.com/projects/codes/X3.4-1963/index.html
 ⁶Revised U.S.A. Standard Code for Information Interchange http://www.wps.com/J/codes/Revised-ASCII/index.html


[spacemanaki]

Some languages do support Unicode for things like arrows and other mathematical symbols: http://wiki.portal.chalmers.se/agda/pmwiki.php?n=ReferenceMa...

Languages which support this (including Agda, I believe) usually support some fallback to ASCII, allowing you to type "->" instead of a Unicode arrow, because it's easier to type on the vast majority of keyboards.

Of course, APL also famously uses all kinds of symbolic nonsense.

[AlexanderDhoore]

Not entirely the same thing, but there are some plugins for Vim, Emacs,... that show different figures/characters in place of things like "=>" or "lambda". But don't actually change your source code.

For example: https://github.com/ehamberg/vim-cute-python