explicitly teach special characters in Code

[kuriwaki]

for beginners, some symbols may seem the same but have vastly different implications in code. It could be good to drill it in rather than try to explain it on a as-you-encounter-it basis.

• . (for numbers) and ,(for parsing arguments)
• ( for arguments and math and { for loops and functions, [ for vectors. Note this is different for TeX. ( is a character, { is for commands and optional argument, and [ is a character. Finally, this is different for Regex: ( is for optional or select, [ is for select from choice,
• = and ==
• spaces -- hard to teach

Here is a rstudio talk on the virtues of explicit, as opposed to open-ended, instruction. https://resources.rstudio.com/rstudio-conf-2019/opening-keynote-day2