duktape-1.8.0/src-separate/duk_hstring_misc.c

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/*
 *  Misc support functions
 */
 
#include "duk_internal.h"
 
DUK_INTERNAL duk_ucodepoint_t duk_hstring_char_code_at_raw(duk_hthread *thr, duk_hstring *h, duk_uint_t pos) {
    duk_uint32_t boff;
    const duk_uint8_t *p, *p_start, *p_end;
    duk_ucodepoint_t cp;
 
    /* Caller must check character offset to be inside the string. */
    DUK_ASSERT(thr != NULL);
    DUK_ASSERT(h != NULL);
    DUK_ASSERT_DISABLE(pos >= 0);  /* unsigned */
    DUK_ASSERT(pos < (duk_uint_t) DUK_HSTRING_GET_CHARLEN(h));
 
    boff = duk_heap_strcache_offset_char2byte(thr, h, (duk_uint32_t) pos);
    DUK_DDD(DUK_DDDPRINT("charCodeAt: pos=%ld -> boff=%ld, str=%!O",
                         (long) pos, (long) boff, (duk_heaphdr *) h));
    DUK_ASSERT_DISABLE(boff >= 0);
    DUK_ASSERT(boff < DUK_HSTRING_GET_BYTELEN(h));
 
    p_start = DUK_HSTRING_GET_DATA(h);
    p_end = p_start + DUK_HSTRING_GET_BYTELEN(h);
    p = p_start + boff;
    DUK_DDD(DUK_DDDPRINT("p_start=%p, p_end=%p, p=%p",
                         (const void *) p_start, (const void *) p_end,
                         (const void *) p));
 
    /* This may throw an error though not for valid E5 strings. */
    cp = duk_unicode_decode_xutf8_checked(thr, &p, p_start, p_end);
    return cp;
}
 
#if !defined(DUK_USE_HSTRING_CLEN)
DUK_INTERNAL duk_size_t duk_hstring_get_charlen(duk_hstring *h) {
    if (DUK_HSTRING_HAS_ASCII(h)) {
        /* Most practical strings will go here. */
        return DUK_HSTRING_GET_BYTELEN(h);
    } else {
        return duk_unicode_unvalidated_utf8_length(DUK_HSTRING_GET_DATA(h), DUK_HSTRING_GET_BYTELEN(h));
    }
}
#endif  /* !DUK_USE_HSTRING_CLEN */