Function: unescape()

unescape(input, enc, emit, position): string

Expand HL7 escape sequences (\F\, \S, \T\, \R, \E\, \.br, \X..\, vendor-specific \Z..) inside a field, component, or subcomponent string. The escape delimiter comes from enc.escape (default ``), so senders using a non-default escape character are handled transparently.

Unknown or malformed sequences are preserved VERBATIM in the output and emit an UNKNOWN_ESCAPE_SEQUENCE warning via emit. Unterminated escapes (an escape character with no closing partner before end-of-input) are also preserved in full and warn once: the scan is strictly O(n) and cannot infinite-loop on malformed input.

Parameters

input

string

enc

EncodingCharacters

emit

(w) => void

position

Hl7Position

Returns

string

Example

import { unescape, DEFAULT_ENCODING_CHARACTERS } from "@cosyte/hl7";
const warnings: Array<unknown> = [];
const out = unescape(
  "patient\\F\\name\\.br\\DOB",
  DEFAULT_ENCODING_CHARACTERS,
  (w) => warnings.push(w),
  { segmentIndex: 1, fieldIndex: 5 },
);
// out === "patient|name\nDOB"