Should You Type Space After Comma?
Why should you type a space after comma? The font for comma should have a space in it.
In Chinese or Japanese language, space is rarely used. This is quite interesting linguistically.
For example, here's the opening passage of the classic Chinese epic novel 西游记 (Journey to the West; Monkey King):
诗曰：混沌未分天地乱，茫茫渺渺无人见。自从盘古破鸿蒙，开辟从兹清浊辨。覆载群生仰至仁，发明万物皆成善。欲知造化会元功，须看西游释厄传。
The gap after punctuation is part of the punctuation character.
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It's interesting because it's a more efficient syntax. In English, why should you type a space after comma? It's redundant. The comma character itself serves the purpose of pause, and the space or gap serves no semantic purpose, but presentation. The comma character should contain a trailing gap itself, or, the rendering system should automatically render a gap after it. Same with exclamation, question mark, period, although the period is abused for many purposes.
You could write a program to convert English punctuation to the equivalent Chinese version，and rid of extra space。For example，this very sentence you are reading，is using Chinese punctuation and there is no space character after comma or period。The problem with this is that it goes against convention，and you'll encounter many little problems。For example，search engine might get confused。
Here is a emacs command that lets you convert. ELisp: Convert Punctuation Between English/Chinese Forms
Similarly, in programing language, often you have style guides on whether to add a space. For example: x=3+4 vs x = 3 + 4, {7,9,10} vs {7, 9, 10}. Software should automatically render the space.