EscapedText

The EscapedText token in RCParsing matches text with escape sequences, such as those found in quoted strings. It’s optimized for parsing text with predefined or custom escape mappings.

Overview

The EscapedText token matches text until it encounters specified sequences, applying escape mappings to produce a processed string. It supports predefined strategies like character prefixes or double characters and allows custom escape mappings. The token produces the unescaped text as its intermediate value.

Example

Here’s an example of parsing a JSON-like string:

var builder = new ParserBuilder();

builder.CreateToken("json_string")
    .EscapedTextPrefix(prefix: '\\', '\\', '\"');

var parser = builder.Build();
var result = parser.MathToken("json_string", "hello\\\"world");
var value = result.GetIntermediateValue<string>(); // "hello"world"

With custom escape mappings:

var escapeMappings = new Dictionary<string, string>
{
    { "\\q", "\"" },
    { "\\n", "\n" }
};
var forbiddenSequences = new[] { "@" };

builder.CreateToken("custom_text")
    .EscapedText(escapeMappings, forbiddenSequences);

var parser = builder.Build();
var result = parser.MatchToken("custom_text", "hello\\qworld\\n");
var value = result.GetIntermediateValue<string>(); // "hello"world\n"

Use Cases

• Quoted Strings: Parse strings with escape sequences, like JSON or C# strings.
• Custom Escapes: Handle domain-specific escape sequences.
• Text Processing: Extract and process text with defined transformations.

Intermediate Values

The EscapedText token produces the processed (unescaped) string as its intermediate value:

builder.CreateToken("sql_string")
    .EscapedTextDoubleChars('\\', '\"');

var parser = builder.Build();
var result = parser.MatchToken("sql_string", "hello''world");
var value = result.GetIntermediateValue<string>(); // "hello'world"

Notes

• Trie-Based: Uses a trie for efficient matching of escape sequences.
• Predefined Strategies: Supports EscapedTextPrefix and EscapedTextDoubleChars.
• Custom Mappings: Allows flexible escape sequence definitions.

Related Tutorials

• TextUntil Token
• CaptureText Token
• Between Token