modeling-app/src/wasm-lib/kcl/src/lsp/util.rs

//! Utility functions for working with ropes and positions.

use ropey::Rope;
use tower_lsp::lsp_types::Position;

pub fn position_to_offset(position: Position, rope: &Rope) -> Option<usize> {
    Some(rope.try_line_to_char(position.line as usize).ok()? + position.character as usize)
}

pub fn get_text_before(offset: usize, rope: &Rope) -> Option<String> {
    if offset == 0 {
        return Some("".to_string());
    }
    Some(rope.slice(0..offset).to_string())
}

pub fn get_text_after(offset: usize, rope: &Rope) -> Option<String> {
    let end_idx = rope.len_chars();
    if offset == end_idx {
        return Some("".to_string());
    }
    Some(rope.slice(offset..end_idx).to_string())
}

pub fn get_line_before(pos: Position, rope: &Rope) -> Option<String> {
    let char_offset = pos.character as usize;
    let offset = position_to_offset(pos, rope).unwrap();
    if char_offset == 0 {
        return Some("".to_string());
    }
    let line_start = offset - char_offset;
    Some(rope.slice(line_start..offset).to_string())
}