Feature: `sz_is_ascii` — SIMD-accelerated pure-ASCII check

[belugabehr]

Describe what you are looking for

Databases frequently need to check if a string is pure ASCII (all bytes < 0x80) to select
between fast ASCII-only code paths and slower Unicode-aware paths. This check gates
case-insensitive search, case conversion, collation, and validation.

Proposed API

/**
 * @brief Check if all bytes in a string are in the ASCII range [0x00, 0x7F].
 * @return sz_true_k if all bytes are ASCII, sz_false_k otherwise.
 */
SZ_DYNAMIC sz_bool_t sz_is_ascii(sz_cptr_t text, sz_size_t length);

Can you contribute to the implementation?

• I can contribute

Is your feature request specific to a certain interface?

It applies to everything

Contact Details

No response

Is there an existing issue for this?

• I have searched the existing issues

Code of Conduct

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