Merge branch develop into claude/perf-iterator-ranges

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/input/number_parse.hpp

@@ -316,6 +316,30 @@ JSON_HEDLEY_ALWAYS_INLINE std::size_t accumulate_digits(const char* data, std::s
     return i;
 }
 
+/// the index of the first byte at or after @a i that is not a digit: the
+/// digits of accumulate_digits() without their value
+JSON_HEDLEY_ALWAYS_INLINE std::size_t skip_digits(const char* data, std::size_t i, std::size_t avail) noexcept
+{
+    while (avail - i >= 8)
+    {
+        if (!is_eight_digits(read_eight_bytes(data + i)))
+        {
+            // a byte of the word is not a digit: no bounds checks before it
+            while (static_cast<unsigned char>(data[i] - '0') <= 9)
+            {
+                ++i;
+            }
+            return i;
+        }
+        i += 8;
+    }
+    while (i < avail && data[i] >= '0' && data[i] <= '9')
+    {
+        ++i;
+    }
+    return i;
+}
+
 /// whether [first, last) contains a digit other than '0'; a plain loop, as
 /// GCC calls std::any_of out of line even for the usual empty range
 JSON_HEDLEY_ALWAYS_INLINE bool has_nonzero_digit(const char* first, const char* last) noexcept

include/nlohmann/detail/input/string_scan.hpp

@@ -520,7 +520,10 @@ JSON_HEDLEY_NEVER_INLINE inline std::size_t string_bulk_run_from(const unsigned
 }
 #endif
 
-// string_bulk_run() for the lexer. With NEON, only the first four words are
+// string_bulk_run() for the lexer. The run must be the longest one: the lexer
+// would only lose speed with a shorter run, but contiguous_parser rejects a
+// string whose run ends at a byte other than a quote or a backslash, so a
+// shorter run would reject valid input there. With NEON, only the first four words are
 // checked inline (most keys and short values end there), and longer runs and
 // non-ASCII text continue out of line. The lexer's scan function runs once per
 // token, and the vector code inlined into it needs more registers, which every