SkipWhitespaces

The SkipWhitespaces token in RCParsing skips whitespace characters before matching a child token. It’s useful for ignoring insignificant whitespace in token patterns.

Overview

The SkipWhitespaces token wraps a single child token and skips any whitespace characters (spaces, tabs, newlines) before attempting to match the child. This simplifies token definitions where whitespace is irrelevant.

Example

Here’s an example of skipping whitespace before a number:

var builder = new ParserBuilder();

builder.CreateToken("number")
    .SkipWhitespaces(b => b.Number<int>());

var parser = builder.Build();
var result = parser.MatchToken("number", "   123");
var value = result.GetIntermediateValue<int>(); // 123

Use Cases

• Whitespace Ignorance: Parse tokens regardless of preceding whitespace.
• Simplified Tokens: Avoid explicit whitespace rules in token definitions.
• Clean Parsing: Handle input with variable whitespace.

Intermediate Values

The SkipWhitespaces token propagates the child’s intermediate value:

builder.CreateToken("keyword")
    .SkipWhitespaces(b => b.KeywordIgnoreCase("if"));

var parser = builder.Build();
var result = parser.MatchToken("keyword", "  IF");
var value = result.GetIntermediateValue<string>(); // "if"

Notes

• Whitespace Definition: Skips spaces, tabs, newlines, and carriage returns.
• Single Child: Only one child token can be specified.
• No Rules: Tokens cannot reference rules, only other tokens.

Related Tutorials

• Whitespaces Token
• Sequence Token
• Number Token