Prerequisite Concepts
Record ends in SGML comments, marked sections, and processing instructions

Record ends occurring in processing instruction text, IGNORE marked section text, and the text of SGML comments are subject to processing as record ends occurring in PCDATA. OmniMark converts the record ends to the value specified by the sgml-out action. If the sgml-out action specifies #none, record-ends are provided to the markup rules in the form in which they come from the SGML parser.

The SGML standard (ISO 8879) doesn't address the processing of text in processing instructions, IGNORE marked sections, or SGML comments, as it does for data content. As a consequence, in these types of text, OmniMark's built-in SGML parser does not discard record-start characters, as it usually does in data content and attribute value text. When the sgml-out action specifies #none, record-start characters will be present in the text.

When the sgml-out action specifies a string:

• any sequence of record-end characters followed immediately by a record-start character (RE, RS) in the text of a processing instruction, IGNORE marked section, or SGML comment, is replaced by that string prior to the text being made available to the OmniMark program, and
• all other record-end and record-start characters will be unchanged.

This processing is different than that for data content and attribute value text in which:

• each record-end is replaced by an sgml-out string, and
• all record-starts are left alone.

This processing ensures that, unless character references are used in strange ways, all "newlines" come out the same.

The conversion of the record-end/record-start sequence to the sgml-out string occurs when the %c operator is processing in a marked-section ignore rule or an sgml-comment rule, just as in a data-content rule. For a processing-instruction rule, the conversion occurs prior to the text of the processing instruction being matched to the pattern at the head of the rule.

The processing of record-starts and record-ends in the text of processing instructions differs between different versions of OmniMark:

• In versions of OmniMark prior to Version 2, record-starts were removed from the text and record-ends were converted to the system-standard line-end character or sequence.
• In versions of OmniMark starting with Version 2 but prior to V2R4, no conversion of record-ends or record-starts was ever done.
• In versions of OmniMark starting with V2R4, the "default" behavior has been made compatible with that of OmniMark prior to Version 2, but the OmniMark programmer has been given control over the processing with the sgml-out action.

Prerequisite Concepts      Record boundaries: manipulating

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