Primitive Lexer Components

Expression	Attribute	Description
`ch`	n/a	Matches `ch`
`char_(ch)`	n/a	Matches `ch`
`str`	n/a	Matches regular expression `str`
`string(str)`	n/a	Matches regular expression `str`
`token_def<Attrib>`	`Attrib`	Matches the immediate argument
`a \| b`	n/a	Matches any of the expressions `a` or `b`
`l[fa]`	Attribute of `l`	Call semantic action `fa` (after matching `l`).

	Note
	The column Attribute in the table above lists the parser attribute exposed by the lexer component if it is used as a parser (see Attribute). A 'n/a' in this columns means the lexer component is not usable as a parser.

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