/**
 * Header text decoding.
 *
 * Layer 0. Imports nothing. Sole owner of turning header bytes into strings.
 *
 * ISO-8859-1 is the identity map onto U+0000..U+00FF, so the whole decoder is
 * `String.fromCharCode`. `TextDecoder` is banned here and everywhere outside `src/tal/`:
 * verified on Node v24.4.0, `TextDecoder('latin1' | 'iso-8859-1' | 'ascii' | 'windows-1252')`
 * all report `encoding === 'windows-1252'` yet decode 0x80 as U+0080, while the WHATWG
 * Encoding Standard mandates U+20AC for those labels. The same header bytes would therefore
 * produce different strings in Node and in a spec-compliant browser.
 */
/** Whether a value is a real one-byte-per-element view, and therefore addressable as file bytes. */
export declare function isByteArray(value: unknown): value is Uint8Array;
/**
 * Decode header bytes as ISO-8859-1: byte `b` becomes code point U+00`b`, always.
 *
 * Never `TextDecoder` — see the module comment.
 */
export declare function decodeHeaderLatin1(bytes: Uint8Array): string;
/**
 * True when the range holds any byte outside printable ASCII 32..126 — the alphabet the EDF
 * spec allows in a header field. Drives `NON_ASCII_HEADER_FIELD`, which is a warning: the
 * field still decodes truthfully as Latin-1, and real equipment writes accented names and a
 * bare 0xB5 for micro.
 *
 * Trailing NUL padding counts, deliberately: it is outside the alphabet too, and the caller
 * that wants to tolerate it can check the padding itself.
 */
export declare function hasNonPrintableAscii(bytes: Uint8Array): boolean;
/**
 * What EDF field padding is, once, for the four modules that act on it.
 *
 * `trimEdfField` below states the rule and the reason: only 0x20 and 0x00, because a trailing TAB
 * or CR is not padding but content the file should not contain, and hiding it here would hide it
 * from `NON_ASCII_HEADER_FIELD`. `bytes/numbers.ts` trims the same padding before parsing a number
 * and `header/fields.ts` finds a field's content bounds inside its own bytes, `header/variant.ts` decides whether the version block is `'0'` and
 * seven pad bytes, and each had grown a byte-identical copy of these two lines with its own pair
 * of constants.
 *
 * Three copies of a rule are three chances for two of them to disagree, and the disagreement would
 * not look like one: a field would trim one way for display and another way for its numeric parse,
 * so `NUMERIC_FIELD_NOT_LEFT_JUSTIFIED` would fire on a field `trimEdfField` had already called
 * clean. `padding.test.ts` checks the rule across all 256 byte values from both public
 * sides, and that every module acting on it imports this rather than growing another.
 */
export declare function isEdfPadding(code: number): boolean;
/**
 * Strip EDF field padding: spaces and NULs, from both ends.
 *
 * EDF pads on the RIGHT with spaces, so trailing padding is the expected case. Leading
 * padding is stripped as well, and that choice is deliberate: a label written `'  Fp1'`
 * names the same electrode as `'Fp1   '`, and text fields are compared, not measured. No
 * evidence is lost by it — every field is also exposed raw and untrimmed, and for numeric
 * fields the non-conformance is reported separately by `parseEdfInteger`/`parseEdfNumber`,
 * which read the untrimmed string.
 *
 * Only 0x20 and 0x00 are stripped. A trailing TAB or CR is not padding, it is content the
 * file should not contain, and hiding it here would hide it from `NON_ASCII_HEADER_FIELD`.
 */
export declare function trimEdfField(text: string): string;
//# sourceMappingURL=latin1.d.ts.map