rust/crates/ra_ide_api/src/syntax_tree.rs
Ville Penttinen 1ef2c06131 Allow syntax strings to contain test markers
We simply remove all the CUSTOM_MARKERS before attempting to parse the file.
This allows for the syntax selection to work with most of the test strings.
2019-03-04 09:19:46 +02:00

88 lines
2.6 KiB
Rust

use ra_db::SourceDatabase;
use crate::db::RootDatabase;
use ra_syntax::{
SourceFile, SyntaxNode, TextRange, AstNode,
algo::{self, visit::{visitor, Visitor}}, ast::{self, AstToken}
};
pub use ra_db::FileId;
pub(crate) fn syntax_tree(
db: &RootDatabase,
file_id: FileId,
text_range: Option<TextRange>,
) -> String {
if let Some(text_range) = text_range {
let file = db.parse(file_id);
let node = algo::find_covering_node(file.syntax(), text_range);
if let Some(tree) = syntax_tree_for_string(node, text_range) {
return tree;
}
node.debug_dump()
} else {
db.parse(file_id).syntax().debug_dump()
}
}
/// Attempts parsing the selected contents of a string literal
/// as rust syntax and returns its syntax tree
fn syntax_tree_for_string(node: &SyntaxNode, text_range: TextRange) -> Option<String> {
// When the range is inside a string
// we'll attempt parsing it as rust syntax
// to provide the syntax tree of the contents of the string
visitor()
.visit(|node: &ast::String| syntax_tree_for_token(node, text_range))
.visit(|node: &ast::RawString| syntax_tree_for_token(node, text_range))
.accept(node)?
}
fn syntax_tree_for_token<T: AstToken>(node: &T, text_range: TextRange) -> Option<String> {
// Range of the full node
let node_range = node.syntax().range();
let text = node.text().to_string();
// We start at some point inside the node
// Either we have selected the whole string
// or our selection is inside it
let start = text_range.start() - node_range.start();
// how many characters we have selected
let len = text_range.len().to_usize();
let node_len = node_range.len().to_usize();
let start = start.to_usize();
// We want to cap our length
let len = len.min(node_len);
// Ensure our slice is inside the actual string
let end = if start + len < text.len() { start + len } else { text.len() - start };
let text = &text[start..end];
// Remove possible extra string quotes from the start
// and the end of the string
let text = text
.trim_start_matches('r')
.trim_start_matches('#')
.trim_start_matches('"')
.trim_end_matches('#')
.trim_end_matches('"')
.trim()
// Remove custom markers
.replace("<|>", "");
let parsed = SourceFile::parse(&text);
// If the "file" parsed without errors,
// return its syntax
if parsed.errors().is_empty() {
return Some(parsed.syntax().debug_dump());
}
None
}