Parsers

Parsers

The Parsers module provides parsing functionality for the SCM programming language. This module includes:

• Parser creation: Functions to create custom parsers using grammar syntax (parser)
• Grammar support: Support for various parser types including AtomParser, RegexParser, AndParser, OrParser, KleeneParser, ManyParser, MaybeParser, and more
• Packrat parsing: Implementation of packrat parsing algorithms for efficient parsing
• Whitespace handling: Configurable whitespace skipping mechanisms

These functions provide essential tools for creating custom parsers and processing structured text data in SCM programs.

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parser

creates a parser

Scm parsers work this way:
(parser syntax scmerresult) -> func

syntax can be one of:
(parser syntax scmerresult) will execute scmerresult after parsing syntax
(parser syntax scmerresult "skipper") will add a different whitespace skipper regex to the root parser
(define var syntax) valid inside (parser...), stores the result of syntax into var for use in scmerresult
"str" AtomParser
(atom "str" caseinsensitive skipws) AtomParser
(regex "asdf" caseinsensitive skipws) RegexParser
'(a b c) AndParser
(or a b c) OrParser
(* sub separator noMemo) KleeneParser
(+ sub separator) ManyParser
(? xyz) MaybeParser (if >1 AndParser)
(not mainparser parser1 parser2 parser3 ...) a parser that matches mainparser but not parser1...
(capture subparser) wraps a parser and returns (matched_text parsed_result)
$ EndParser
empty EmptyParser
symbol -> use other parser defined in env

for further details on packrat parsers, take a look at https://github.com/launix-de/go-packrat

Allowed number of parameters: 1–3

Parameters

• syntax (any): syntax of the grammar (see docs)
• generator (any): (optional) expressions to evaluate. All captured variables are available in the scope. (optional)
• skipper (string): (optional) string that defines the skip mechanism for whitespaces as regexp (optional)

Returns

func