Constant statement¶

Outputs literal text. Supports escape sequences and optional JSON field formatting when an outname and format are specified. .. summary-end

This statement specifies constant text. It is primarily intended for text-based output so constant fragments, such as newlines, can be included. Example from the testbench:

template(name="outfmt" type="list") {
    property(name="$!usr!msgnum")
    constant(value="\n")
}

The following escape sequences are recognized inside the constant text:

\\ – single backslash
\n – LF
\ooo – three octal digits representing a character (\101 is "A"). Exactly three digits must be given.
\xhh – two hexadecimal digits representing a character (\x41 is "A"). Exactly two digits must be given.

If an unsupported character follows a backslash, behavior is unpredictable.

When creating structured outputs, constant text without an outname parameter is ignored. To include constant data in the name/value tree, provide outname as shown:

template(name="outfmt" type="list") {
    property(name="$!usr!msgnum")
    constant(value="\n" outname="IWantThisInMyDB")
}

To generate a constant JSON field the format parameter can be used:

template(name="outfmt" type="list" option.jsonf="on") {
          property(outname="message" name="msg" format="jsonf")
          constant(outname="@version" value="1" format="jsonf")
}

Here the constant statement generates "@version":"1". Both value and format must be specified.

When you want dotted outname values to be emitted as nested objects, enable option.jsonftree="on" on the template instead of option.jsonf.

Parameters¶

value – constant value to emit
outname – output field name for structured outputs
format – empty or jsonf

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