Fix precedence of 'not' operator (#11672)

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# Description

A bit hackish but this fixes the precedence of the `not` operator.

Before: `not false and false` => true

Now: `not false and false` => false

Fixes #11633

# User-Facing Changes
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---------

Co-authored-by: Jakub Žádník <kubouch@gmail.com>

crates/nu-parser/src/parser.rs

@@ -3025,6 +3025,14 @@ pub fn expand_to_cell_path(
 
         *expression = new_expression;
     }
+
+    if let Expression {
+        expr: Expr::UnaryNot(inner),
+        ..
+    } = expression
+    {
+        expand_to_cell_path(working_set, inner, var_id);
+    }
 }
 
 pub fn parse_input_output_types(
@@ -4846,6 +4854,8 @@ pub fn parse_math_expression(
 
     let first_span = working_set.get_span_contents(spans[0]);
 
+    let mut not_start_spans = vec![];
+
     if first_span == b"if" || first_span == b"match" {
         // If expression
         if spans.len() > 1 {
@@ -4858,24 +4868,40 @@ pub fn parse_math_expression(
             return garbage(spans[0]);
         }
     } else if first_span == b"not" {
-        if spans.len() > 1 {
-            let remainder = parse_math_expression(working_set, &spans[1..], lhs_row_var_id);
-            return Expression {
-                expr: Expr::UnaryNot(Box::new(remainder)),
-                span: span(spans),
-                ty: Type::Bool,
-                custom_completion: None,
-            };
+        not_start_spans.push(spans[idx].start);
+        idx += 1;
+        while idx < spans.len() {
+            let next_value = working_set.get_span_contents(spans[idx]);
+
+            if next_value == b"not" {
+                not_start_spans.push(spans[idx].start);
+                idx += 1;
             } else {
-            working_set.error(ParseError::Expected(
-                "expression",
-                Span::new(spans[0].end, spans[0].end),
-            ));
-            return garbage(spans[0]);
+                break;
             }
         }
 
-    let mut lhs = parse_value(working_set, spans[0], &SyntaxShape::Any);
+        if idx == spans.len() {
+            working_set.error(ParseError::Expected(
+                "expression",
+                Span::new(spans[idx - 1].end, spans[idx - 1].end),
+            ));
+            return garbage(spans[idx - 1]);
+        }
+    }
+
+    let mut lhs = parse_value(working_set, spans[idx], &SyntaxShape::Any);
+
+    for not_start_span in not_start_spans.iter().rev() {
+        lhs = Expression {
+            expr: Expr::UnaryNot(Box::new(lhs)),
+            span: Span::new(*not_start_span, spans[idx].end),
+            ty: Type::Bool,
+            custom_completion: None,
+        };
+    }
+    not_start_spans.clear();
+
     idx += 1;
 
     if idx >= spans.len() {
@@ -4906,13 +4932,45 @@ pub fn parse_math_expression(
 
         let content = working_set.get_span_contents(spans[idx]);
         // allow `if` to be a special value for assignment.
+
         if content == b"if" || content == b"match" {
             let rhs = parse_call(working_set, &spans[idx..], spans[0], false);
             expr_stack.push(op);
             expr_stack.push(rhs);
             break;
+        } else if content == b"not" {
+            not_start_spans.push(spans[idx].start);
+            idx += 1;
+            while idx < spans.len() {
+                let next_value = working_set.get_span_contents(spans[idx]);
+
+                if next_value == b"not" {
+                    not_start_spans.push(spans[idx].start);
+                    idx += 1;
+                } else {
+                    break;
                 }
-        let rhs = parse_value(working_set, spans[idx], &SyntaxShape::Any);
+            }
+
+            if idx == spans.len() {
+                working_set.error(ParseError::Expected(
+                    "expression",
+                    Span::new(spans[idx - 1].end, spans[idx - 1].end),
+                ));
+                return garbage(spans[idx - 1]);
+            }
+        }
+        let mut rhs = parse_value(working_set, spans[idx], &SyntaxShape::Any);
+
+        for not_start_span in not_start_spans.iter().rev() {
+            rhs = Expression {
+                expr: Expr::UnaryNot(Box::new(rhs)),
+                span: Span::new(*not_start_span, spans[idx].end),
+                ty: Type::Bool,
+                custom_completion: None,
+            };
+        }
+        not_start_spans.clear();
 
         while op_prec <= last_prec && expr_stack.len() > 1 {
             // Collapse the right associated operations first

src/tests/test_math.rs

@@ -105,6 +105,26 @@ fn not_contains() -> TestResult {
     run_test("'testme' !~ 'test'", "false")
 }
 
+#[test]
+fn not_precedence() -> TestResult {
+    run_test("not false and false", "false")
+}
+
+#[test]
+fn not_precedence2() -> TestResult {
+    run_test("(not false) and false", "false")
+}
+
+#[test]
+fn not_precedence3() -> TestResult {
+    run_test("not not true and true", "true")
+}
+
+#[test]
+fn not_precedence4() -> TestResult {
+    run_test("not not true and not not true", "true")
+}
+
 #[test]
 fn floating_add() -> TestResult {
     run_test("10.1 + 0.8", "10.9")