Fix 7 parser tests by improving explain output

internal/explain/expressions.go

@@ -47,6 +47,15 @@ func explainLiteral(sb *strings.Builder, n *ast.Literal, indent string, depth in
 				fmt.Fprintf(sb, "%s ExpressionList\n", indent)
 				return
 			}
+			// Single-element tuples (from trailing comma syntax like (1,)) always render as Function tuple
+			if len(exprs) == 1 {
+				fmt.Fprintf(sb, "%sFunction tuple (children %d)\n", indent, 1)
+				fmt.Fprintf(sb, "%s ExpressionList (children %d)\n", indent, len(exprs))
+				for _, e := range exprs {
+					Node(sb, e, depth+2)
+				}
+				return
+			}
 			hasComplexExpr := false
 			for _, e := range exprs {
 				// Simple literals (numbers, strings, etc.) are OK
@@ -454,11 +463,16 @@ func explainAliasedExpr(sb *strings.Builder, n *ast.AliasedExpr, depth int) {
 			explainCastExpr(sb, e, indent, depth)
 		}
 	case *ast.ArrayAccess:
-		// Array access - ClickHouse doesn't show aliases on arrayElement in EXPLAIN AST
-		explainArrayAccess(sb, e, indent, depth)
+		// Array access - show alias only when array is not a literal
+		// ClickHouse hides alias when array access is on a literal
+		if _, isLit := e.Array.(*ast.Literal); isLit {
+			explainArrayAccess(sb, e, indent, depth)
+		} else {
+			explainArrayAccessWithAlias(sb, e, n.Alias, indent, depth)
+		}
 	case *ast.TupleAccess:
-		// Tuple access - ClickHouse doesn't show aliases on tupleElement in EXPLAIN AST
-		explainTupleAccess(sb, e, indent, depth)
+		// Tuple access with alias
+		explainTupleAccessWithAlias(sb, e, n.Alias, indent, depth)
 	case *ast.InExpr:
 		// IN expressions with alias
 		explainInExprWithAlias(sb, e, n.Alias, indent, depth)

internal/explain/functions.go

@@ -395,19 +395,20 @@ func explainInExpr(sb *strings.Builder, n *ast.InExpr, indent string, depth int)
 				argCount += len(n.List)
 			}
 		} else {
-			// Check if all items are tuples
-			allTuples := true
+			// Check if all items are string literals (large list case - no wrapper)
+			allStringLiterals := true
 			for _, item := range n.List {
-				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralTuple {
-					allTuples = false
+				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralString {
+					allStringLiterals = false
 					break
 				}
 			}
-			if allTuples {
-				// All tuples get wrapped in a single Function tuple
-				argCount++
-			} else {
+			if allStringLiterals {
+				// Large string list - separate children
 				argCount += len(n.List)
+			} else {
+				// Non-string items get wrapped in a single Function tuple
+				argCount++
 			}
 		}
 	}
@@ -455,8 +456,26 @@ func explainInExpr(sb *strings.Builder, n *ast.InExpr, indent string, depth int)
 				explainTupleInInList(sb, item.(*ast.Literal), indent+"   ", depth+4)
 			}
 		} else {
+			// Check if all items are string literals (large list case)
+			allStringLiterals := true
 			for _, item := range n.List {
-				Node(sb, item, depth+2)
+				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralString {
+					allStringLiterals = false
+					break
+				}
+			}
+			if allStringLiterals {
+				// Large string list - output as separate children (no tuple wrapper)
+				for _, item := range n.List {
+					Node(sb, item, depth+2)
+				}
+			} else {
+				// Wrap non-literal/non-tuple list items in Function tuple
+				fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
+				fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(n.List))
+				for _, item := range n.List {
+					Node(sb, item, depth+4)
+				}
 			}
 		}
 	}
@@ -548,18 +567,20 @@ func explainInExprWithAlias(sb *strings.Builder, n *ast.InExpr, alias string, in
 				argCount += len(n.List)
 			}
 		} else {
-			// Check if all items are tuples
-			allTuples := true
+			// Check if all items are string literals (large list case - no wrapper)
+			allStringLiterals := true
 			for _, item := range n.List {
-				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralTuple {
-					allTuples = false
+				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralString {
+					allStringLiterals = false
 					break
 				}
 			}
-			if allTuples {
-				argCount++
-			} else {
+			if allStringLiterals {
+				// Large string list - separate children
 				argCount += len(n.List)
+			} else {
+				// Non-string items get wrapped in a single Function tuple
+				argCount++
 			}
 		}
 	}
@@ -600,8 +621,26 @@ func explainInExprWithAlias(sb *strings.Builder, n *ast.InExpr, alias string, in
 				explainTupleInInList(sb, item.(*ast.Literal), indent+"   ", depth+4)
 			}
 		} else {
+			// Check if all items are string literals (large list case)
+			allStringLiterals := true
 			for _, item := range n.List {
-				Node(sb, item, depth+2)
+				if lit, ok := item.(*ast.Literal); !ok || lit.Type != ast.LiteralString {
+					allStringLiterals = false
+					break
+				}
+			}
+			if allStringLiterals {
+				// Large string list - output as separate children (no tuple wrapper)
+				for _, item := range n.List {
+					Node(sb, item, depth+2)
+				}
+			} else {
+				// Wrap non-literal/non-tuple list items in Function tuple
+				fmt.Fprintf(sb, "%s  Function tuple (children %d)\n", indent, 1)
+				fmt.Fprintf(sb, "%s   ExpressionList (children %d)\n", indent, len(n.List))
+				for _, item := range n.List {
+					Node(sb, item, depth+4)
+				}
 			}
 		}
 	}

parser/expression.go

@@ -895,6 +895,10 @@ func (p *Parser) parseGroupedOrTuple() ast.Expression {
 		elements := []ast.Expression{first}
 		for p.currentIs(token.COMMA) {
 			p.nextToken()
+			// Handle trailing comma: (1,) should create tuple with single element
+			if p.currentIs(token.RPAREN) {
+				break
+			}
 			elements = append(elements, p.parseExpression(LOWEST))
 		}
 		p.expect(token.RPAREN)

parser/testdata/00017_aggregation_uninitialized_memory/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/00172_constexprs_in_set/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/00604_show_create_database/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/00606_quantiles_and_nans/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/00840_top_k_weighted/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/01021_tuple_parser/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/01277_large_tuples/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/01407_lambda_arrayJoin/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/01813_quantileBfloat16_nans/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/02163_operators/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/02265_limit_push_down_over_window_functions_bug/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/02336_sort_optimization_with_fill/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/02513_date_string_comparison/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/02810_row_binary_with_defaults/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}

parser/testdata/02922_respect_nulls_Nullable/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/03203_system_numbers_limit_and_offset_complex/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/03221_refreshable_matview_progress/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/03258_old_analyzer_const_expr_bug/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/03630_join_blocks_with_different_constness/metadata.json

@@ -1 +1 @@
-{"explain":false,"todo":true,"todo_format":true}
+{"todo_format":true,"explain":false}

parser/testdata/03713_data_types_binary_deserialization_stack_overflow/metadata.json

@@ -1 +1 @@
-{"todo":true,"todo_format":true}
+{"todo_format":true}