Extracting Spans

The SpanTracer is a powerful utility in rhai_trace that extracts spans from Rhai scripts, mapping every statement or expression to its exact location in the source code. It provides byte offsets, line numbers, and column positions, enabling precise diagnostics, navigation, and analysis.

Purpose

• Parses scripts to identify code segments
• Associates syntax elements with their location in the source text
• Facilitates error highlighting, debugging tools, and developer feedback mechanisms

Example Usage

use rhai_trace::{SpanTracer, Span};

let code = r#"
    let a = 1;
    let b = a + 2;
"#;

let tracer = SpanTracer::new();
let spans = tracer.extract_from(code).unwrap();

for span in spans {
    println!("Span: {}..{} (line {}, column {})",
             span.start(), span.end(), span.line(), span.column());
}

This outputs each segment’s location, allowing tools to provide targeted information based on where the error or expression occurs.

Methods

• SpanTracer::new() Creates a new SpanTracer instance.

• SpanTracer::extract_from(script) Analyzes the provided script and returns a Vec<Span> containing all identified spans. Fails with an error if the script cannot be parsed.