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Niels Lohmann
3dbed2a0cb
The lexer counted the read position on every character: two increments and a newline check per get(), all on members kept in memory. For seekable input (pointers, strings, other random-access byte ranges) the position can be derived instead: chars_read_total is the adapter's read count (including reads at EOF) minus a pending unget, and line and column are recomputed from the consumed input only when get_position() is called, i.e. on parse errors. JSON_DIAGNOSTIC_POSITIONS uses the new O(1) get_chars_read_total(). Stream, file, wide-string and user-defined adapters keep the eager counters. Parsing pretty-printed input gets 8-12% faster and accept() 12-27% (canada, citm_catalog, twitter; clang 21 arm64 and GCC 13 x86-64). Error messages, byte offsets, SAX positions and diagnostic positions are unchanged (differential comparison against develop on 548k inputs). Signed-off-by: Niels Lohmann <mail@nlohmann.me>