Converting ″Straight Quotes″ to “Curly Quotes”

Question

I have an application which uses a Javascript-based rules engine. I need a way to convert regular straight quotes into curly (or smart) quotes. It’d be easy to just do a <

Answer 1

You could replace all that preceed a word character with the left quote, and all that follow a word character with a right quote.

str = str.replace(/"(?=\w|$)/g, "“");
str = str.replace(/(?<=\w|^)"/g, "”"); // IF the language supports look-
                                             // behind. Otherwise, see below.

As pointed out in the comments below, this doesn't take punctuation into account, but easily can:

/(?<=[\w,.?!\)]|^)"/g

[Edit:] For languages that don't support look-behind, like Javascript, as long as you replace all the front-facing ones first, you have two options:

str = str.replace(/"/g, "”"); // Replace the rest with right curly quotes
// or...
str = str.replace(/\b"/g, "”"); // Replace any quotes after a word
                                      // boundary with right curly quotes

(I've left the original solution above in case this is helpful to someone using a language that does support look-behind)