There are no problems caused by using unary delimiters for strings, because using paired delimiters for strings doesn't solve the problems unary delimiters create.
By nature, strings contain arbitrary text. Paired delimiters have one virtue over unary: they nest, but this virtue is only evident when a syntax requires that they must nest, and this is not the case for strings. It's but a small victory to reduce the need for some sort of escaping, without eliminating it.
Of the bewildering variety of partial solutions to the dilemma, none fully satisfactory, I consider the `backtick quote' pairing among the worst. Aside from the aesthetic problems, which can be fixed with the right choice of font, the bare apostrophe is much more common in plain text than an unmatched double quote, and the convention does nothing to help.
This comes at the cost of losing a type of string, and backtick strings are well-used in many languages, including by you in your second paragraph. What we would get in return for this loss is, nothing, because `don't' is just as invalid as 'don't' and requires much the same solution. `This is `not worth it', you see', especially as languages like to treat strings as single tokens (many exceptions notwithstanding) and this introduces a push-down to that parse for, again, no appreciable benefit.
I do agree with you about C and character literals, however. The close quote isn't needed and always struck me as somewhat wasteful. 'a is cleaner, and reduces the odds of typing "a" when you mean 'a'.
By nature, strings contain arbitrary text. Paired delimiters have one virtue over unary: they nest, but this virtue is only evident when a syntax requires that they must nest, and this is not the case for strings. It's but a small victory to reduce the need for some sort of escaping, without eliminating it.
Of the bewildering variety of partial solutions to the dilemma, none fully satisfactory, I consider the `backtick quote' pairing among the worst. Aside from the aesthetic problems, which can be fixed with the right choice of font, the bare apostrophe is much more common in plain text than an unmatched double quote, and the convention does nothing to help.
This comes at the cost of losing a type of string, and backtick strings are well-used in many languages, including by you in your second paragraph. What we would get in return for this loss is, nothing, because `don't' is just as invalid as 'don't' and requires much the same solution. `This is `not worth it', you see', especially as languages like to treat strings as single tokens (many exceptions notwithstanding) and this introduces a push-down to that parse for, again, no appreciable benefit.
I do agree with you about C and character literals, however. The close quote isn't needed and always struck me as somewhat wasteful. 'a is cleaner, and reduces the odds of typing "a" when you mean 'a'.