Chapter 2. Loading grammars

Before it can be used, a parser must be constructed for the grammar. You can load Invisible XML grammars in either the text or XML syntax. You can also load grammars in the CoffeeGrinder compiled format.

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Note

The API has been redesigned and greatly simplified in version 2.x. Instead of having a few different functions that take a grammar as an argument, there are now just a couple of functions that return a parser for the grammar.

The parser creation functions return an XPath function that takes a single argument, the string to be parsed. If the grammar cannot be parsed, an error is raised. This error can be captured with try/catch.

2.1. cs:load-grammar

This function takes the URI of an Invisible XML grammar and constructs a parser for that grammar.

cs:load-grammar($uri)→function($input as xs:string) as item()

$uri

xs:string

A URI that identifies an Invisible XML grammar

cs:load-grammar($uri, $options)→function($input as xs:string) as item()

$uri	xs:string	A URI that identifies an Invisible XML grammar
$options	map(xs:string, item())	Grammar options

See Chapter 5, Parser options for a description of the available options.

If the return format is XML, an XML node will be returned. For the JSON return types, an XDM map will be returned.

2.2. cs:make-parser

This function takes an Invisible XML grammar and constructs a parser for that grammar.

cs:make-parser($input)→function($input as xs:string) as item()

$input

item()

An input grammar

cs:make-parser($input, $options)→function($input as xs:string) as item()

$input	item()	An input grammar
$options	map(xs:string, item())	Grammar options

Exactly what this function does depends on the type of $input.

XML node: The input is assumed to be an XML version of an invisible XML grammar (a “visible XML grammar”). The function will attempt to construct a parser for that grammar.
xs:anyURI: The input is assumed to be a URI that identifies the location of an invisible XML grammar. It will be loaded and parsed just as cs:load-grammar would.
xs:anyAtomicType: The string value of the input is assumed to be an Invisible XML grammar. The function will attempt to construct a parser for that grammar.
anything else: Any other input will cause an error.

See Chapter 5, Parser options for a description of the available options.

If the return format is XML, an XML node will be returned. For the JSON return types, an XDM map will be returned.