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Fix exponential parser time on sequence of [[[[ (#10439)
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@ -4004,29 +4004,18 @@ fn parse_table_expression(working_set: &mut StateWorkingSet, span: Span) -> Expr
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working_set.error(err);
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}
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let head = if let Some(first) = tokens.first() {
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if working_set.get_span_contents(first.span).starts_with(b"[") {
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parse_list_expression(working_set, first.span, &SyntaxShape::Any)
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} else {
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return parse_list_expression(working_set, span, &SyntaxShape::Any);
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}
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} else {
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// Check that we have all arguments first, before trying to parse the first
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// in order to avoid exponential parsing time
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let [first, second, rest @ ..] = &tokens[..] else {
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return parse_list_expression(working_set, span, &SyntaxShape::Any);
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};
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if tokens
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.get(1)
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.filter(|second| second.contents == TokenContents::Semicolon)
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.is_none()
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if !working_set.get_span_contents(first.span).starts_with(b"[")
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|| second.contents != TokenContents::Semicolon
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|| rest.is_empty()
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{
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return parse_list_expression(working_set, span, &SyntaxShape::Any);
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};
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let rest = &tokens[2..];
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if rest.is_empty() {
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return parse_list_expression(working_set, span, &SyntaxShape::Any);
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}
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let head = parse_list_expression(working_set, first.span, &SyntaxShape::Any);
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let head = {
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let Expression {
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expr: Expr::List(vals),
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@ -455,6 +455,13 @@ fn single_value_row_condition() -> TestResult {
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)
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}
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#[test]
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fn performance_nested_lists() -> TestResult {
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// Parser used to be exponential on deeply nested lists
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// TODO: Add a timeout
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fail_test(r#"[[[[[[[[[[[[[[[[[[[[[[[[[[[["#, "Unexpected end of code")
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}
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#[test]
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fn unary_not_1() -> TestResult {
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run_test(r#"not false"#, "true")
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