Converting Smart Quotes in PHP

When dealing with text, it's often necessary to convert various types of smart quotes to regular quotes. However, existing conversion functions may fall short in handling all possible quote variations.

To address this issue, a comprehensive solution can be devised using a combination of techniques:

1. Mapping Unicode Code Points:
   Utilize a mapping array like $chr_map to replace specific UTF-8 code points with their corresponding Unicode equivalents. This covers the majority of smart quote types.
2. Normalization:
   If the input text may contain code points from Windows codepage 1252, apply a separate map ($normalization_map) to normalize these codes to regular Unicode.
3. Combining Techniques:
   Combine the output from the mapping and normalization steps to create a consolidated map for all supported quote variations.
4. Using str_replace():
   Efficiently apply the consolidated map to the input string using str_replace().
5. Deferring to Simple Transformations:
   Include additional transformations for simple quote characters that don't require complex mappings.

This approach ensures comprehensive handling of all quote variations, providing a reliable solution for converting smart quotes in PHP.