EOF

The EOF token in RCParsing matches the end of the input or the current barrier position. It’s used to ensure that the parser has consumed all input.

Overview

The EOF token succeeds only when there are no more characters to parse. It’s essential for validating complete input parsing.

Example

Here’s an example of ensuring all input is parsed:

var builder = new ParserBuilder();

builder.Settings.SkipWhitespaces();

builder.CreateRule("main")
    .ZeroOrMore(b => b.Identifier())
    .EOF();

var parser = builder.Build();
var result = parser.ParseRule("main", "a b c"); // Succeeds
var result2 = parser.ParseRule("main", "a b c d"); // Succeeds

Use Cases

• Complete Parsing: Ensure no trailing characters remain.
• Grammar Termination: Mark the end of a grammar rule.
• Barrier Handling: Match the end of a barrier-delimited section.

Intermediate Values

The EOF token does not produce an intermediate value:

builder.CreateToken("eof")
    .EOF();

var parser = builder.Build();
var result = parser.MatchToken("eof", "");
var value = result.TryGetIntermediateValue<object>(); // null

Notes

• Zero-Width: Does not consume input unless at the end.

Related Tutorials

• Sequence Token
• Choice Token