Function extract_prefix 

pub fn extract_prefix(content: &str, position: Position, range: Range) -> String

Extracts the prefix text from content at a position within a range.

This function finds the text from the start of the range up to the cursor position, excluding any quote characters.

Arguments

• content - Full document content
• position - Cursor position (LSP Position, 0-based line, UTF-16 character offset)
• range - Range containing the token (name, version, etc.)

Returns

The prefix string typed so far, with quotes and extra whitespace removed.

Examples

use deps_core::completion::extract_prefix;
use tower_lsp_server::ls_types::{Position, Range};

let content = r#"serde = "1.0""#;
let position = Position { line: 0, character: 11 }; // After "1."
let range = Range {
    start: Position { line: 0, character: 9 },
    end: Position { line: 0, character: 13 },
};

let prefix = extract_prefix(content, position, range);
assert_eq!(prefix, "1.");