HL7v2.Parser (HL7v2 v3.10.1)

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Parses HL7v2 messages into raw representation with canonical round-trip fidelity.

The parser splits the message into segments, fields, repetitions, components, and sub-components using the delimiters declared in the MSH segment header. No type coercion or validation is performed. Line endings are normalized to CR and a trailing CR is always present, so parse(text) |> encode() produces the canonical wire form (which may differ from the input only in line-ending normalization).

MSH-1/MSH-2 Special Handling

MSH-1 (field separator) and MSH-2 (encoding characters) are not regular delimited fields. The parser handles them as special cases:

  • MSH-1 is stored as a single-byte binary (the field separator character)
  • MSH-2 is stored as a 4- or 5-character literal string (encoding characters)
  • Remaining MSH fields start at field index 2 (MSH-3 = index 2)

Examples

iex> {:ok, msg} = HL7v2.Parser.parse("MSH|^~\\&|SEND|FAC||RCV||20240101||ADT^A01|123|P|2.5\r")
iex> msg.type
{"ADT", "A01"}
iex> length(msg.segments)
1

Summary

Functions

parse(text, opts \\ [])

Parses an HL7v2 message binary into a RawMessage struct.

Functions

parse(text, opts \\ [])

@spec parse(
  binary(),
  keyword()
) :: {:ok, HL7v2.RawMessage.t() | HL7v2.TypedMessage.t()} | {:error, term()}

Parses an HL7v2 message binary into a RawMessage struct.

Options

  • :mode — :raw (default) or :typed for parsed segment structs.
  • :copy — true to copy all parsed binaries (prevents GC reference to original message binary). Use when storing parsed messages long-term. Default false.

Returns {:ok, raw_message} or {:error, reason}.