Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-ssr/src/matching.rs')
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diff --git a/crates/ide-ssr/src/matching.rs b/crates/ide-ssr/src/matching.rs new file mode 100644 index 0000000000..ba2a99c5d4 --- /dev/null +++ b/crates/ide-ssr/src/matching.rs @@ -0,0 +1,803 @@ +//! This module is responsible for matching a search pattern against a node in the AST. In the +//! process of matching, placeholder values are recorded. + +use crate::{ + parsing::{Constraint, NodeKind, Placeholder, Var}, + resolving::{ResolvedPattern, ResolvedRule, UfcsCallInfo}, + SsrMatches, +}; +use hir::Semantics; +use ide_db::{base_db::FileRange, FxHashMap}; +use std::{cell::Cell, iter::Peekable}; +use syntax::{ + ast::{self, AstNode, AstToken}, + SmolStr, SyntaxElement, SyntaxElementChildren, SyntaxKind, SyntaxNode, SyntaxToken, +}; + +// Creates a match error. If we're currently attempting to match some code that we thought we were +// going to match, as indicated by the --debug-snippet flag, then populate the reason field. +macro_rules! match_error { + ($e:expr) => {{ + MatchFailed { + reason: if recording_match_fail_reasons() { + Some(format!("{}", $e)) + } else { + None + } + } + }}; + ($fmt:expr, $($arg:tt)+) => {{ + MatchFailed { + reason: if recording_match_fail_reasons() { + Some(format!($fmt, $($arg)+)) + } else { + None + } + } + }}; +} + +// Fails the current match attempt, recording the supplied reason if we're recording match fail reasons. +macro_rules! fail_match { + ($($args:tt)*) => {return Err(match_error!($($args)*))}; +} + +/// Information about a match that was found. +#[derive(Debug)] +pub struct Match { + pub(crate) range: FileRange, + pub(crate) matched_node: SyntaxNode, + pub(crate) placeholder_values: FxHashMap<Var, PlaceholderMatch>, + pub(crate) ignored_comments: Vec<ast::Comment>, + pub(crate) rule_index: usize, + /// The depth of matched_node. + pub(crate) depth: usize, + // Each path in the template rendered for the module in which the match was found. + pub(crate) rendered_template_paths: FxHashMap<SyntaxNode, hir::ModPath>, +} + +/// Information about a placeholder bound in a match. +#[derive(Debug)] +pub(crate) struct PlaceholderMatch { + pub(crate) range: FileRange, + /// More matches, found within `node`. + pub(crate) inner_matches: SsrMatches, + /// How many times the code that the placeholder matched needed to be dereferenced. Will only be + /// non-zero if the placeholder matched to the receiver of a method call. + pub(crate) autoderef_count: usize, + pub(crate) autoref_kind: ast::SelfParamKind, +} + +#[derive(Debug)] +pub(crate) struct MatchFailureReason { + pub(crate) reason: String, +} + +/// An "error" indicating that matching failed. Use the fail_match! macro to create and return this. +#[derive(Clone)] +pub(crate) struct MatchFailed { + /// The reason why we failed to match. Only present when debug_active true in call to + /// `get_match`. + pub(crate) reason: Option<String>, +} + +/// Checks if `code` matches the search pattern found in `search_scope`, returning information about +/// the match, if it does. Since we only do matching in this module and searching is done by the +/// parent module, we don't populate nested matches. +pub(crate) fn get_match( + debug_active: bool, + rule: &ResolvedRule, + code: &SyntaxNode, + restrict_range: &Option<FileRange>, + sema: &Semantics<ide_db::RootDatabase>, +) -> Result<Match, MatchFailed> { + record_match_fails_reasons_scope(debug_active, || { + Matcher::try_match(rule, code, restrict_range, sema) + }) +} + +/// Checks if our search pattern matches a particular node of the AST. +struct Matcher<'db, 'sema> { + sema: &'sema Semantics<'db, ide_db::RootDatabase>, + /// If any placeholders come from anywhere outside of this range, then the match will be + /// rejected. + restrict_range: Option<FileRange>, + rule: &'sema ResolvedRule, +} + +/// Which phase of matching we're currently performing. We do two phases because most attempted +/// matches will fail and it means we can defer more expensive checks to the second phase. +enum Phase<'a> { + /// On the first phase, we perform cheap checks. No state is mutated and nothing is recorded. + First, + /// On the second phase, we construct the `Match`. Things like what placeholders bind to is + /// recorded. + Second(&'a mut Match), +} + +impl<'db, 'sema> Matcher<'db, 'sema> { + fn try_match( + rule: &ResolvedRule, + code: &SyntaxNode, + restrict_range: &Option<FileRange>, + sema: &'sema Semantics<'db, ide_db::RootDatabase>, + ) -> Result<Match, MatchFailed> { + let match_state = Matcher { sema, restrict_range: *restrict_range, rule }; + // First pass at matching, where we check that node types and idents match. + match_state.attempt_match_node(&mut Phase::First, &rule.pattern.node, code)?; + match_state.validate_range(&sema.original_range(code))?; + let mut the_match = Match { + range: sema.original_range(code), + matched_node: code.clone(), + placeholder_values: FxHashMap::default(), + ignored_comments: Vec::new(), + rule_index: rule.index, + depth: 0, + rendered_template_paths: FxHashMap::default(), + }; + // Second matching pass, where we record placeholder matches, ignored comments and maybe do + // any other more expensive checks that we didn't want to do on the first pass. + match_state.attempt_match_node( + &mut Phase::Second(&mut the_match), + &rule.pattern.node, + code, + )?; + the_match.depth = sema.ancestors_with_macros(the_match.matched_node.clone()).count(); + if let Some(template) = &rule.template { + the_match.render_template_paths(template, sema)?; + } + Ok(the_match) + } + + /// Checks that `range` is within the permitted range if any. This is applicable when we're + /// processing a macro expansion and we want to fail the match if we're working with a node that + /// didn't originate from the token tree of the macro call. + fn validate_range(&self, range: &FileRange) -> Result<(), MatchFailed> { + if let Some(restrict_range) = &self.restrict_range { + if restrict_range.file_id != range.file_id + || !restrict_range.range.contains_range(range.range) + { + fail_match!("Node originated from a macro"); + } + } + Ok(()) + } + + fn attempt_match_node( + &self, + phase: &mut Phase, + pattern: &SyntaxNode, + code: &SyntaxNode, + ) -> Result<(), MatchFailed> { + // Handle placeholders. + if let Some(placeholder) = self.get_placeholder_for_node(pattern) { + for constraint in &placeholder.constraints { + self.check_constraint(constraint, code)?; + } + if let Phase::Second(matches_out) = phase { + let original_range = self.sema.original_range(code); + // We validated the range for the node when we started the match, so the placeholder + // probably can't fail range validation, but just to be safe... + self.validate_range(&original_range)?; + matches_out.placeholder_values.insert( + placeholder.ident.clone(), + PlaceholderMatch::from_range(original_range), + ); + } + return Ok(()); + } + // We allow a UFCS call to match a method call, provided they resolve to the same function. + if let Some(pattern_ufcs) = self.rule.pattern.ufcs_function_calls.get(pattern) { + if let Some(code) = ast::MethodCallExpr::cast(code.clone()) { + return self.attempt_match_ufcs_to_method_call(phase, pattern_ufcs, &code); + } + if let Some(code) = ast::CallExpr::cast(code.clone()) { + return self.attempt_match_ufcs_to_ufcs(phase, pattern_ufcs, &code); + } + } + if pattern.kind() != code.kind() { + fail_match!( + "Pattern had `{}` ({:?}), code had `{}` ({:?})", + pattern.text(), + pattern.kind(), + code.text(), + code.kind() + ); + } + // Some kinds of nodes have special handling. For everything else, we fall back to default + // matching. + match code.kind() { + SyntaxKind::RECORD_EXPR_FIELD_LIST => { + self.attempt_match_record_field_list(phase, pattern, code) + } + SyntaxKind::TOKEN_TREE => self.attempt_match_token_tree(phase, pattern, code), + SyntaxKind::PATH => self.attempt_match_path(phase, pattern, code), + _ => self.attempt_match_node_children(phase, pattern, code), + } + } + + fn attempt_match_node_children( + &self, + phase: &mut Phase, + pattern: &SyntaxNode, + code: &SyntaxNode, + ) -> Result<(), MatchFailed> { + self.attempt_match_sequences( + phase, + PatternIterator::new(pattern), + code.children_with_tokens(), + ) + } + + fn attempt_match_sequences( + &self, + phase: &mut Phase, + pattern_it: PatternIterator, + mut code_it: SyntaxElementChildren, + ) -> Result<(), MatchFailed> { + let mut pattern_it = pattern_it.peekable(); + loop { + match phase.next_non_trivial(&mut code_it) { + None => { + if let Some(p) = pattern_it.next() { + fail_match!("Part of the pattern was unmatched: {:?}", p); + } + return Ok(()); + } + Some(SyntaxElement::Token(c)) => { + self.attempt_match_token(phase, &mut pattern_it, &c)?; + } + Some(SyntaxElement::Node(c)) => match pattern_it.next() { + Some(SyntaxElement::Node(p)) => { + self.attempt_match_node(phase, &p, &c)?; + } + Some(p) => fail_match!("Pattern wanted '{}', code has {}", p, c.text()), + None => fail_match!("Pattern reached end, code has {}", c.text()), + }, + } + } + } + + fn attempt_match_token( + &self, + phase: &mut Phase, + pattern: &mut Peekable<PatternIterator>, + code: &syntax::SyntaxToken, + ) -> Result<(), MatchFailed> { + phase.record_ignored_comments(code); + // Ignore whitespace and comments. + if code.kind().is_trivia() { + return Ok(()); + } + if let Some(SyntaxElement::Token(p)) = pattern.peek() { + // If the code has a comma and the pattern is about to close something, then accept the + // comma without advancing the pattern. i.e. ignore trailing commas. + if code.kind() == SyntaxKind::COMMA && is_closing_token(p.kind()) { + return Ok(()); + } + // Conversely, if the pattern has a comma and the code doesn't, skip that part of the + // pattern and continue to match the code. + if p.kind() == SyntaxKind::COMMA && is_closing_token(code.kind()) { + pattern.next(); + } + } + // Consume an element from the pattern and make sure it matches. + match pattern.next() { + Some(SyntaxElement::Token(p)) => { + if p.kind() != code.kind() || p.text() != code.text() { + fail_match!( + "Pattern wanted token '{}' ({:?}), but code had token '{}' ({:?})", + p.text(), + p.kind(), + code.text(), + code.kind() + ) + } + } + Some(SyntaxElement::Node(p)) => { + // Not sure if this is actually reachable. + fail_match!( + "Pattern wanted {:?}, but code had token '{}' ({:?})", + p, + code.text(), + code.kind() + ); + } + None => { + fail_match!("Pattern exhausted, while code remains: `{}`", code.text()); + } + } + Ok(()) + } + + fn check_constraint( + &self, + constraint: &Constraint, + code: &SyntaxNode, + ) -> Result<(), MatchFailed> { + match constraint { + Constraint::Kind(kind) => { + kind.matches(code)?; + } + Constraint::Not(sub) => { + if self.check_constraint(&*sub, code).is_ok() { + fail_match!("Constraint {:?} failed for '{}'", constraint, code.text()); + } + } + } + Ok(()) + } + + /// Paths are matched based on whether they refer to the same thing, even if they're written + /// differently. + fn attempt_match_path( + &self, + phase: &mut Phase, + pattern: &SyntaxNode, + code: &SyntaxNode, + ) -> Result<(), MatchFailed> { + if let Some(pattern_resolved) = self.rule.pattern.resolved_paths.get(pattern) { + let pattern_path = ast::Path::cast(pattern.clone()).unwrap(); + let code_path = ast::Path::cast(code.clone()).unwrap(); + if let (Some(pattern_segment), Some(code_segment)) = + (pattern_path.segment(), code_path.segment()) + { + // Match everything within the segment except for the name-ref, which is handled + // separately via comparing what the path resolves to below. + self.attempt_match_opt( + phase, + pattern_segment.generic_arg_list(), + code_segment.generic_arg_list(), + )?; + self.attempt_match_opt( + phase, + pattern_segment.param_list(), + code_segment.param_list(), + )?; + } + if matches!(phase, Phase::Second(_)) { + let resolution = self + .sema + .resolve_path(&code_path) + .ok_or_else(|| match_error!("Failed to resolve path `{}`", code.text()))?; + if pattern_resolved.resolution != resolution { + fail_match!("Pattern had path `{}` code had `{}`", pattern.text(), code.text()); + } + } + } else { + return self.attempt_match_node_children(phase, pattern, code); + } + Ok(()) + } + + fn attempt_match_opt<T: AstNode>( + &self, + phase: &mut Phase, + pattern: Option<T>, + code: Option<T>, + ) -> Result<(), MatchFailed> { + match (pattern, code) { + (Some(p), Some(c)) => self.attempt_match_node(phase, p.syntax(), c.syntax()), + (None, None) => Ok(()), + (Some(p), None) => fail_match!("Pattern `{}` had nothing to match", p.syntax().text()), + (None, Some(c)) => { + fail_match!("Nothing in pattern to match code `{}`", c.syntax().text()) + } + } + } + + /// We want to allow the records to match in any order, so we have special matching logic for + /// them. + fn attempt_match_record_field_list( + &self, + phase: &mut Phase, + pattern: &SyntaxNode, + code: &SyntaxNode, + ) -> Result<(), MatchFailed> { + // Build a map keyed by field name. + let mut fields_by_name: FxHashMap<SmolStr, SyntaxNode> = FxHashMap::default(); + for child in code.children() { + if let Some(record) = ast::RecordExprField::cast(child.clone()) { + if let Some(name) = record.field_name() { + fields_by_name.insert(name.text().into(), child.clone()); + } + } + } + for p in pattern.children_with_tokens() { + if let SyntaxElement::Node(p) = p { + if let Some(name_element) = p.first_child_or_token() { + if self.get_placeholder(&name_element).is_some() { + // If the pattern is using placeholders for field names then order + // independence doesn't make sense. Fall back to regular ordered + // matching. + return self.attempt_match_node_children(phase, pattern, code); + } + if let Some(ident) = only_ident(name_element) { + let code_record = fields_by_name.remove(ident.text()).ok_or_else(|| { + match_error!( + "Placeholder has record field '{}', but code doesn't", + ident + ) + })?; + self.attempt_match_node(phase, &p, &code_record)?; + } + } + } + } + if let Some(unmatched_fields) = fields_by_name.keys().next() { + fail_match!( + "{} field(s) of a record literal failed to match, starting with {}", + fields_by_name.len(), + unmatched_fields + ); + } + Ok(()) + } + + /// Outside of token trees, a placeholder can only match a single AST node, whereas in a token + /// tree it can match a sequence of tokens. Note, that this code will only be used when the + /// pattern matches the macro invocation. For matches within the macro call, we'll already have + /// expanded the macro. + fn attempt_match_token_tree( + &self, + phase: &mut Phase, + pattern: &SyntaxNode, + code: &syntax::SyntaxNode, + ) -> Result<(), MatchFailed> { + let mut pattern = PatternIterator::new(pattern).peekable(); + let mut children = code.children_with_tokens(); + while let Some(child) = children.next() { + if let Some(placeholder) = pattern.peek().and_then(|p| self.get_placeholder(p)) { + pattern.next(); + let next_pattern_token = pattern + .peek() + .and_then(|p| match p { + SyntaxElement::Token(t) => Some(t.clone()), + SyntaxElement::Node(n) => n.first_token(), + }) + .map(|p| p.text().to_string()); + let first_matched_token = child.clone(); + let mut last_matched_token = child; + // Read code tokens util we reach one equal to the next token from our pattern + // or we reach the end of the token tree. + for next in &mut children { + match &next { + SyntaxElement::Token(t) => { + if Some(t.to_string()) == next_pattern_token { + pattern.next(); + break; + } + } + SyntaxElement::Node(n) => { + if let Some(first_token) = n.first_token() { + if Some(first_token.text()) == next_pattern_token.as_deref() { + if let Some(SyntaxElement::Node(p)) = pattern.next() { + // We have a subtree that starts with the next token in our pattern. + self.attempt_match_token_tree(phase, &p, n)?; + break; + } + } + } + } + }; + last_matched_token = next; + } + if let Phase::Second(match_out) = phase { + match_out.placeholder_values.insert( + placeholder.ident.clone(), + PlaceholderMatch::from_range(FileRange { + file_id: self.sema.original_range(code).file_id, + range: first_matched_token + .text_range() + .cover(last_matched_token.text_range()), + }), + ); + } + continue; + } + // Match literal (non-placeholder) tokens. + match child { + SyntaxElement::Token(token) => { + self.attempt_match_token(phase, &mut pattern, &token)?; + } + SyntaxElement::Node(node) => match pattern.next() { + Some(SyntaxElement::Node(p)) => { + self.attempt_match_token_tree(phase, &p, &node)?; + } + Some(SyntaxElement::Token(p)) => fail_match!( + "Pattern has token '{}', code has subtree '{}'", + p.text(), + node.text() + ), + None => fail_match!("Pattern has nothing, code has '{}'", node.text()), + }, + } + } + if let Some(p) = pattern.next() { + fail_match!("Reached end of token tree in code, but pattern still has {:?}", p); + } + Ok(()) + } + + fn attempt_match_ufcs_to_method_call( + &self, + phase: &mut Phase, + pattern_ufcs: &UfcsCallInfo, + code: &ast::MethodCallExpr, + ) -> Result<(), MatchFailed> { + use ast::HasArgList; + let code_resolved_function = self + .sema + .resolve_method_call(code) + .ok_or_else(|| match_error!("Failed to resolve method call"))?; + if pattern_ufcs.function != code_resolved_function { + fail_match!("Method call resolved to a different function"); + } + // Check arguments. + let mut pattern_args = pattern_ufcs + .call_expr + .arg_list() + .ok_or_else(|| match_error!("Pattern function call has no args"))? + .args(); + // If the function we're calling takes a self parameter, then we store additional + // information on the placeholder match about autoderef and autoref. This allows us to use + // the placeholder in a context where autoderef and autoref don't apply. + if code_resolved_function.self_param(self.sema.db).is_some() { + if let (Some(pattern_type), Some(expr)) = + (&pattern_ufcs.qualifier_type, &code.receiver()) + { + let deref_count = self.check_expr_type(pattern_type, expr)?; + let pattern_receiver = pattern_args.next(); + self.attempt_match_opt(phase, pattern_receiver.clone(), code.receiver())?; + if let Phase::Second(match_out) = phase { + if let Some(placeholder_value) = pattern_receiver + .and_then(|n| self.get_placeholder_for_node(n.syntax())) + .and_then(|placeholder| { + match_out.placeholder_values.get_mut(&placeholder.ident) + }) + { + placeholder_value.autoderef_count = deref_count; + placeholder_value.autoref_kind = self + .sema + .resolve_method_call_as_callable(code) + .and_then(|callable| callable.receiver_param(self.sema.db)) + .map(|self_param| self_param.kind()) + .unwrap_or(ast::SelfParamKind::Owned); + } + } + } + } else { + self.attempt_match_opt(phase, pattern_args.next(), code.receiver())?; + } + let mut code_args = + code.arg_list().ok_or_else(|| match_error!("Code method call has no args"))?.args(); + loop { + match (pattern_args.next(), code_args.next()) { + (None, None) => return Ok(()), + (p, c) => self.attempt_match_opt(phase, p, c)?, + } + } + } + + fn attempt_match_ufcs_to_ufcs( + &self, + phase: &mut Phase, + pattern_ufcs: &UfcsCallInfo, + code: &ast::CallExpr, + ) -> Result<(), MatchFailed> { + use ast::HasArgList; + // Check that the first argument is the expected type. + if let (Some(pattern_type), Some(expr)) = ( + &pattern_ufcs.qualifier_type, + &code.arg_list().and_then(|code_args| code_args.args().next()), + ) { + self.check_expr_type(pattern_type, expr)?; + } + self.attempt_match_node_children(phase, pattern_ufcs.call_expr.syntax(), code.syntax()) + } + + /// Verifies that `expr` matches `pattern_type`, possibly after dereferencing some number of + /// times. Returns the number of times it needed to be dereferenced. + fn check_expr_type( + &self, + pattern_type: &hir::Type, + expr: &ast::Expr, + ) -> Result<usize, MatchFailed> { + use hir::HirDisplay; + let code_type = self + .sema + .type_of_expr(expr) + .ok_or_else(|| { + match_error!("Failed to get receiver type for `{}`", expr.syntax().text()) + })? + .original; + // Temporary needed to make the borrow checker happy. + let res = code_type + .autoderef(self.sema.db) + .enumerate() + .find(|(_, deref_code_type)| pattern_type == deref_code_type) + .map(|(count, _)| count) + .ok_or_else(|| { + match_error!( + "Pattern type `{}` didn't match code type `{}`", + pattern_type.display(self.sema.db), + code_type.display(self.sema.db) + ) + }); + res + } + + fn get_placeholder_for_node(&self, node: &SyntaxNode) -> Option<&Placeholder> { + self.get_placeholder(&SyntaxElement::Node(node.clone())) + } + + fn get_placeholder(&self, element: &SyntaxElement) -> Option<&Placeholder> { + only_ident(element.clone()).and_then(|ident| self.rule.get_placeholder(&ident)) + } +} + +impl Match { + fn render_template_paths( + &mut self, + template: &ResolvedPattern, + sema: &Semantics<ide_db::RootDatabase>, + ) -> Result<(), MatchFailed> { + let module = sema + .scope(&self.matched_node) + .ok_or_else(|| match_error!("Matched node isn't in a module"))? + .module(); + for (path, resolved_path) in &template.resolved_paths { + if let hir::PathResolution::Def(module_def) = resolved_path.resolution { + let mod_path = module.find_use_path(sema.db, module_def).ok_or_else(|| { + match_error!("Failed to render template path `{}` at match location") + })?; + self.rendered_template_paths.insert(path.clone(), mod_path); + } + } + Ok(()) + } +} + +impl Phase<'_> { + fn next_non_trivial(&mut self, code_it: &mut SyntaxElementChildren) -> Option<SyntaxElement> { + loop { + let c = code_it.next(); + if let Some(SyntaxElement::Token(t)) = &c { + self.record_ignored_comments(t); + if t.kind().is_trivia() { + continue; + } + } + return c; + } + } + + fn record_ignored_comments(&mut self, token: &SyntaxToken) { + if token.kind() == SyntaxKind::COMMENT { + if let Phase::Second(match_out) = self { + if let Some(comment) = ast::Comment::cast(token.clone()) { + match_out.ignored_comments.push(comment); + } + } + } + } +} + +fn is_closing_token(kind: SyntaxKind) -> bool { + kind == SyntaxKind::R_PAREN || kind == SyntaxKind::R_CURLY || kind == SyntaxKind::R_BRACK +} + +pub(crate) fn record_match_fails_reasons_scope<F, T>(debug_active: bool, f: F) -> T +where + F: Fn() -> T, +{ + RECORDING_MATCH_FAIL_REASONS.with(|c| c.set(debug_active)); + let res = f(); + RECORDING_MATCH_FAIL_REASONS.with(|c| c.set(false)); + res +} + +// For performance reasons, we don't want to record the reason why every match fails, only the bit +// of code that the user indicated they thought would match. We use a thread local to indicate when +// we are trying to match that bit of code. This saves us having to pass a boolean into all the bits +// of code that can make the decision to not match. +thread_local! { + pub static RECORDING_MATCH_FAIL_REASONS: Cell<bool> = Cell::new(false); +} + +fn recording_match_fail_reasons() -> bool { + RECORDING_MATCH_FAIL_REASONS.with(|c| c.get()) +} + +impl PlaceholderMatch { + fn from_range(range: FileRange) -> Self { + Self { + range, + inner_matches: SsrMatches::default(), + autoderef_count: 0, + autoref_kind: ast::SelfParamKind::Owned, + } + } +} + +impl NodeKind { + fn matches(&self, node: &SyntaxNode) -> Result<(), MatchFailed> { + let ok = match self { + Self::Literal => { + cov_mark::hit!(literal_constraint); + ast::Literal::can_cast(node.kind()) + } + }; + if !ok { + fail_match!("Code '{}' isn't of kind {:?}", node.text(), self); + } + Ok(()) + } +} + +// If `node` contains nothing but an ident then return it, otherwise return None. +fn only_ident(element: SyntaxElement) -> Option<SyntaxToken> { + match element { + SyntaxElement::Token(t) => { + if t.kind() == SyntaxKind::IDENT { + return Some(t); + } + } + SyntaxElement::Node(n) => { + let mut children = n.children_with_tokens(); + if let (Some(only_child), None) = (children.next(), children.next()) { + return only_ident(only_child); + } + } + } + None +} + +struct PatternIterator { + iter: SyntaxElementChildren, +} + +impl Iterator for PatternIterator { + type Item = SyntaxElement; + + fn next(&mut self) -> Option<SyntaxElement> { + for element in &mut self.iter { + if !element.kind().is_trivia() { + return Some(element); + } + } + None + } +} + +impl PatternIterator { + fn new(parent: &SyntaxNode) -> Self { + Self { iter: parent.children_with_tokens() } + } +} + +#[cfg(test)] +mod tests { + use crate::{MatchFinder, SsrRule}; + + #[test] + fn parse_match_replace() { + let rule: SsrRule = "foo($x) ==>> bar($x)".parse().unwrap(); + let input = "fn foo() {} fn bar() {} fn main() { foo(1+2); }"; + + let (db, position, selections) = crate::tests::single_file(input); + let mut match_finder = MatchFinder::in_context(&db, position, selections).unwrap(); + match_finder.add_rule(rule).unwrap(); + let matches = match_finder.matches(); + assert_eq!(matches.matches.len(), 1); + assert_eq!(matches.matches[0].matched_node.text(), "foo(1+2)"); + assert_eq!(matches.matches[0].placeholder_values.len(), 1); + + let edits = match_finder.edits(); + assert_eq!(edits.len(), 1); + let edit = &edits[&position.file_id]; + let mut after = input.to_string(); + edit.apply(&mut after); + assert_eq!(after, "fn foo() {} fn bar() {} fn main() { bar(1+2); }"); + } +} |