A plain text expression is made up from a string of characters inside double quotes, along with escape characters to allow for special characters to be used. It evaluates to a fixed string (an actual human readable string).
This page describes the syntax for string literal expressions in PhixFlow.
All expressions in PhixFlow are written in the PhixFlow scripting language, //and every expression resolves to one of the following:
- A regular expresion, following the POSIX style
- A string literal expression
Regular expressions are used for text pattern-matching, whereas plain text expressions can be used both to do literal character matching and provide output values. In simple terms, writing a plain text expression for a string valued field on a stream would result in a (that) string being output to the database, but a regular expression would have no meaning in this context.
Examples:
If you want the string abc"def.
Use single quotes if you want to embed a double quote (or visa versa), or prefix the quote with a backslash:
e.g. 'abc"def' or "abc\"def".
Note how this contrasts to the regular expression case, where a double-backslash is used to escape special characters.