IBM Streams 4.3.0

Grammar notation

This language specification adopts a flavor of Backus-Naur Form (BNF) to describe the syntax of language features.

SPL uses the following conventions:

Table 1. Notations used in SPL
Notations	Meaning
`Italics`	Non-terminal.
`ALL_CAPS_ITALICS`	Token. For example, `ID` for identifiers.
`'fixed-width font'`	Verbatim text that is quoted to avoid confusion with meta-characters. For example: '`(`'
(...)	Grouping - to disambiguate meta-syntax precedence.
... \| ...	Alternatives - to match syntax on either left or right of the bar.
...^?	The syntax that precedes this notation is optional.
...^*	The syntax that precedes this notation is repeated zero or more times.
...⁺	The syntax that precedes this notation is repeated one or more times.
...^*,	Comma-separated list of zero or more items.
...^+,	Comma-separated list of one or more items.
...^*;	Semicolon separated list of zero or more items.
...^+;	Semicolon separated list of one or more items.
...^+.	Period separated list of one or more items.
`nonTerminal ::=` ...	Rule definition.