111 lines
2.7 KiB
Rust
111 lines
2.7 KiB
Rust
use crate::{
|
|
syntax::Syntax,
|
|
tree_sitter::{Node, Tree},
|
|
Rope, RopeSlice, State,
|
|
};
|
|
|
|
const TAB_WIDTH: usize = 4;
|
|
|
|
fn indent_level_for_line(line: RopeSlice) -> usize {
|
|
let mut len = 0;
|
|
for ch in line.chars() {
|
|
match ch {
|
|
'\t' => len += TAB_WIDTH,
|
|
' ' => len += 1,
|
|
_ => break,
|
|
}
|
|
}
|
|
|
|
len / TAB_WIDTH
|
|
}
|
|
|
|
/// Find the highest syntax node at position.
|
|
/// This is to identify the column where this node (e.g., an HTML closing tag) ends.
|
|
fn get_highest_syntax_node_at_bytepos(syntax: &Syntax, pos: usize) -> Option<Node> {
|
|
let tree = syntax.root_layer.tree.as_ref().unwrap();
|
|
|
|
let mut node = match tree.root_node().named_descendant_for_byte_range(pos, pos) {
|
|
Some(node) => node,
|
|
None => return None,
|
|
};
|
|
|
|
while let Some(parent) = node.parent() {
|
|
if parent.start_byte() == node.start_byte() {
|
|
node = parent
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
Some(node)
|
|
}
|
|
|
|
fn walk(node: Option<Node>) -> usize {
|
|
let node = match node {
|
|
Some(node) => node,
|
|
None => return 0,
|
|
};
|
|
|
|
let parent = match node.parent() {
|
|
Some(node) => node,
|
|
None => return 0,
|
|
};
|
|
|
|
let mut increment = 0;
|
|
|
|
let not_first_or_last_sibling = node.next_sibling().is_some() && node.prev_sibling().is_some();
|
|
let is_scope = true;
|
|
|
|
if not_first_or_last_sibling && is_scope {
|
|
increment += 1;
|
|
}
|
|
|
|
walk(Some(parent)) + increment
|
|
}
|
|
|
|
// for_line_at_col
|
|
fn suggested_indent_for_line(state: &State, line_num: usize) -> usize {
|
|
let line = state.doc.line(line_num);
|
|
let current = indent_level_for_line(line);
|
|
|
|
let mut byte_start = state.doc.line_to_byte(line_num);
|
|
|
|
// find first non-whitespace char
|
|
for ch in line.chars() {
|
|
// TODO: could use memchr with chunks?
|
|
if ch != ' ' && ch != '\t' {
|
|
break;
|
|
}
|
|
byte_start += 1;
|
|
}
|
|
|
|
if let Some(syntax) = &state.syntax {
|
|
let node = get_highest_syntax_node_at_bytepos(state.syntax.as_ref().unwrap(), byte_start);
|
|
|
|
// let indentation = walk()
|
|
// special case for comments
|
|
|
|
// if preserve_leading_whitespace
|
|
|
|
unimplemented!()
|
|
} else {
|
|
// TODO: case for non-tree sitter grammars
|
|
0
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use super::*;
|
|
|
|
#[test]
|
|
fn indent_level() {
|
|
let line = Rope::from(" fn new"); // 8 spaces
|
|
assert_eq!(indent_level_for_line(line.slice(..)), 2);
|
|
let line = Rope::from("\t\t\tfn new"); // 3 tabs
|
|
assert_eq!(indent_level_for_line(line.slice(..)), 3);
|
|
// mixed indentation
|
|
let line = Rope::from("\t \tfn new"); // 1 tab, 4 spaces, tab
|
|
assert_eq!(indent_level_for_line(line.slice(..)), 3);
|
|
}
|
|
}
|