Chapter 2. EBNF symbols used in this document

Chapter 2. EBNF symbols used in this document
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Chapter 2. EBNF symbols used in this document

Because there are several variations of EBNF, the following table explains the symbols used in this document:

Table 2.1. EBNF symbols used in this document

Symbol	Meaning	Example
`[space]`	concatenation	`"foo" "bar"` yields: `foo bar foo bar foo bar` etc.
`\|`	or	`"yes" \| "no" \| "maybe"` yields: `yes no maybe`
`->`	alternative or	`-> "foo" "bar" -> "tar" "zar"` is equivalent to: `( "foo" "bar" ) \| ( "tar" "zar" )` yields: `foo bar tar zar`
`?`	optional (0 or 1 occurrences)	`"foo" ?` yields: `[nothing] foo`
`*`	0, 1 or more occurrences	`"foo" *` yields: `[nothing] foo foo foo foo foo foo` etc.
`+`	1 or more occurrences	`"foo" +` yields: `foo foo foo foo foo foo` etc.
`( )`	grouping of several elements	`( "foo" \| "bar" ) +` yields: `foo bar foo bar bar foo foo foo foo bar foo foo bar` etc.
`&`	line continuation character (not standard EBNF)	`"foo" \| & "bar \| & "zar"` is equivalent to: `"foo" \| "bar \| "zar"`
`/* */`	comment (not standard EBNF)	`/* this is a comment */`

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