Fix 10+ parser tests with various improvements

ast/ast.go

@@ -41,6 +41,16 @@ func (s *SelectWithUnionQuery) Pos() token.Position { return s.Position }
 func (s *SelectWithUnionQuery) End() token.Position { return s.Position }
 func (s *SelectWithUnionQuery) statementNode()      {}
 
+// SelectIntersectExceptQuery represents SELECT ... INTERSECT/EXCEPT ... queries.
+type SelectIntersectExceptQuery struct {
+	Position token.Position `json:"-"`
+	Selects  []Statement    `json:"selects"`
+}
+
+func (s *SelectIntersectExceptQuery) Pos() token.Position { return s.Position }
+func (s *SelectIntersectExceptQuery) End() token.Position { return s.Position }
+func (s *SelectIntersectExceptQuery) statementNode()      {}
+
 // SelectQuery represents a SELECT statement.
 type SelectQuery struct {
 	Position    token.Position        `json:"-"`
@@ -212,6 +222,8 @@ type InsertQuery struct {
 	Function    *FunctionCall  `json:"function,omitempty"` // For INSERT INTO FUNCTION syntax
 	Columns     []*Identifier  `json:"columns,omitempty"`
 	PartitionBy Expression     `json:"partition_by,omitempty"` // For PARTITION BY clause
+	Infile      string         `json:"infile,omitempty"`       // For FROM INFILE clause
+	Compression string         `json:"compression,omitempty"`  // For COMPRESSION clause
 	Select      Statement      `json:"select,omitempty"`
 	Format      *Identifier    `json:"format,omitempty"`
 	HasSettings bool           `json:"has_settings,omitempty"` // For SETTINGS clause

internal/explain/explain.go

@@ -31,6 +31,8 @@ func Node(sb *strings.Builder, node interface{}, depth int) {
 	// Select statements
 	case *ast.SelectWithUnionQuery:
 		explainSelectWithUnionQuery(sb, n, indent, depth)
+	case *ast.SelectIntersectExceptQuery:
+		explainSelectIntersectExceptQuery(sb, n, indent, depth)
 	case *ast.SelectQuery:
 		explainSelectQuery(sb, n, indent, depth)
 

internal/explain/expressions.go

@@ -81,14 +81,58 @@ func explainLiteral(sb *strings.Builder, n *ast.Literal, indent string, depth in
 				fmt.Fprintf(sb, "%s ExpressionList\n", indent)
 				return
 			}
-			hasComplexExpr := false
+			// Check if we should render as Function array
+			// This happens when:
+			// 1. Contains non-literal, non-negation expressions OR
+			// 2. Contains tuples OR
+			// 3. Contains nested arrays that all have exactly 1 element (homogeneous single-element arrays) OR
+			// 4. Contains nested arrays with non-literal expressions OR
+			// 5. Contains nested arrays that are empty or contain tuples/non-literals
+			shouldUseFunctionArray := false
+			allAreSingleElementArrays := true
+			hasNestedArrays := false
+			nestedArraysNeedFunctionFormat := false
+
 			for _, e := range exprs {
-				if !isSimpleLiteralOrNegation(e) {
-					hasComplexExpr = true
-					break
+				if lit, ok := e.(*ast.Literal); ok {
+					if lit.Type == ast.LiteralArray {
+						hasNestedArrays = true
+						// Check if this inner array has exactly 1 element
+						if innerExprs, ok := lit.Value.([]ast.Expression); ok {
+							if len(innerExprs) != 1 {
+								allAreSingleElementArrays = false
+							}
+							// Check if inner array needs Function array format:
+							// - Contains non-literal expressions OR
+							// - Contains tuples OR
+							// - Is empty OR
+							// - Contains empty arrays
+							if containsNonLiteralExpressions(innerExprs) ||
+								len(innerExprs) == 0 ||
+								containsTuples(innerExprs) ||
+								containsEmptyArrays(innerExprs) {
+								nestedArraysNeedFunctionFormat = true
+							}
+						} else {
+							allAreSingleElementArrays = false
+						}
+					} else if lit.Type == ast.LiteralTuple {
+						// Tuples are complex
+						shouldUseFunctionArray = true
+					}
+				} else if !isSimpleLiteralOrNegation(e) {
+					shouldUseFunctionArray = true
 				}
 			}
-			if hasComplexExpr {
+
+			// Use Function array when:
+			// - nested arrays that are ALL single-element
+			// - nested arrays that need Function format (contain non-literals, tuples, or empty arrays)
+			if hasNestedArrays && (allAreSingleElementArrays || nestedArraysNeedFunctionFormat) {
+				shouldUseFunctionArray = true
+			}
+
+			if shouldUseFunctionArray {
 				// Render as Function array instead of Literal
 				fmt.Fprintf(sb, "%sFunction array (children %d)\n", indent, 1)
 				fmt.Fprintf(sb, "%s ExpressionList (children %d)\n", indent, len(exprs))
@@ -124,6 +168,58 @@ func isSimpleLiteralOrNegation(e ast.Expression) bool {
 	return false
 }
 
+// containsOnlyArraysOrTuples checks if a slice of expressions contains
+// only array or tuple literals (including empty arrays).
+// Returns true if the slice is empty or contains only arrays/tuples.
+func containsOnlyArraysOrTuples(exprs []ast.Expression) bool {
+	if len(exprs) == 0 {
+		return true // empty is considered "only arrays"
+	}
+	for _, e := range exprs {
+		if lit, ok := e.(*ast.Literal); ok {
+			if lit.Type != ast.LiteralArray && lit.Type != ast.LiteralTuple {
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+	return true
+}
+
+// containsNonLiteralExpressions checks if a slice of expressions contains
+// any non-literal expressions (identifiers, function calls, etc.)
+func containsNonLiteralExpressions(exprs []ast.Expression) bool {
+	for _, e := range exprs {
+		if _, ok := e.(*ast.Literal); !ok {
+			return true
+		}
+	}
+	return false
+}
+
+// containsTuples checks if a slice of expressions contains any tuple literals
+func containsTuples(exprs []ast.Expression) bool {
+	for _, e := range exprs {
+		if lit, ok := e.(*ast.Literal); ok && lit.Type == ast.LiteralTuple {
+			return true
+		}
+	}
+	return false
+}
+
+// containsEmptyArrays checks if a slice of expressions contains any empty array literals
+func containsEmptyArrays(exprs []ast.Expression) bool {
+	for _, e := range exprs {
+		if lit, ok := e.(*ast.Literal); ok && lit.Type == ast.LiteralArray {
+			if innerExprs, ok := lit.Value.([]ast.Expression); ok && len(innerExprs) == 0 {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 func explainBinaryExpr(sb *strings.Builder, n *ast.BinaryExpr, indent string, depth int) {
 	// Convert operator to function name
 	fnName := OperatorToFunction(n.Op)
@@ -303,11 +399,20 @@ func explainAsterisk(sb *strings.Builder, n *ast.Asterisk, indent string) {
 
 func explainWithElement(sb *strings.Builder, n *ast.WithElement, indent string, depth int) {
 	// For WITH elements, we need to show the underlying expression with the name as alias
+	// When name is empty, don't show the alias part
 	switch e := n.Query.(type) {
 	case *ast.Literal:
-		fmt.Fprintf(sb, "%sLiteral %s (alias %s)\n", indent, FormatLiteral(e), n.Name)
+		if n.Name != "" {
+			fmt.Fprintf(sb, "%sLiteral %s (alias %s)\n", indent, FormatLiteral(e), n.Name)
+		} else {
+			fmt.Fprintf(sb, "%sLiteral %s\n", indent, FormatLiteral(e))
+		}
 	case *ast.Identifier:
-		fmt.Fprintf(sb, "%sIdentifier %s (alias %s)\n", indent, e.Name(), n.Name)
+		if n.Name != "" {
+			fmt.Fprintf(sb, "%sIdentifier %s (alias %s)\n", indent, e.Name(), n.Name)
+		} else {
+			fmt.Fprintf(sb, "%sIdentifier %s\n", indent, e.Name())
+		}
 	case *ast.FunctionCall:
 		explainFunctionCallWithAlias(sb, e, n.Name, indent, depth)
 	case *ast.BinaryExpr:
@@ -316,19 +421,31 @@ func explainWithElement(sb *strings.Builder, n *ast.WithElement, indent string,
 		// For || (concat) operator, flatten chained concatenations
 		if e.Op == "||" {
 			operands := collectConcatOperands(e)
-			fmt.Fprintf(sb, "%sFunction %s (alias %s) (children %d)\n", indent, fnName, n.Name, 1)
+			if n.Name != "" {
+				fmt.Fprintf(sb, "%sFunction %s (alias %s) (children %d)\n", indent, fnName, n.Name, 1)
+			} else {
+				fmt.Fprintf(sb, "%sFunction %s (children %d)\n", indent, fnName, 1)
+			}
 			fmt.Fprintf(sb, "%s ExpressionList (children %d)\n", indent, len(operands))
 			for _, op := range operands {
 				Node(sb, op, depth+2)
 			}
 		} else {
-			fmt.Fprintf(sb, "%sFunction %s (alias %s) (children %d)\n", indent, fnName, n.Name, 1)
+			if n.Name != "" {
+				fmt.Fprintf(sb, "%sFunction %s (alias %s) (children %d)\n", indent, fnName, n.Name, 1)
+			} else {
+				fmt.Fprintf(sb, "%sFunction %s (children %d)\n", indent, fnName, 1)
+			}
 			fmt.Fprintf(sb, "%s ExpressionList (children %d)\n", indent, 2)
 			Node(sb, e.Left, depth+2)
 			Node(sb, e.Right, depth+2)
 		}
 	case *ast.Subquery:
-		fmt.Fprintf(sb, "%sSubquery (alias %s) (children %d)\n", indent, n.Name, 1)
+		if n.Name != "" {
+			fmt.Fprintf(sb, "%sSubquery (alias %s) (children %d)\n", indent, n.Name, 1)
+		} else {
+			fmt.Fprintf(sb, "%sSubquery (children %d)\n", indent, 1)
+		}
 		Node(sb, e.Query, depth+1)
 	default:
 		// For other types, just output the expression (alias may be lost)

internal/explain/format.go

@@ -208,7 +208,6 @@ func NormalizeFunctionName(name string) string {
 		"lcase":       "lower",
 		"ucase":       "upper",
 		"mid":         "substring",
-		"substr":      "substring",
 		"ceiling":     "ceil",
 		"ln":          "log",
 		"log10":       "log10",

internal/explain/functions.go

@@ -179,10 +179,39 @@ func explainInExpr(sb *strings.Builder, n *ast.InExpr, indent string, depth int)
 		fnName = "global" + strings.Title(fnName)
 	}
 	fmt.Fprintf(sb, "%sFunction %s (children %d)\n", indent, fnName, 1)
+
+	// Determine if the IN list should be combined into a single tuple literal
+	// This happens when we have multiple literals of the same type:
+	// - All numeric literals (integers/floats)
+	// - All tuple literals
+	canBeTupleLiteral := false
+	if n.Query == nil && len(n.List) > 1 {
+		allNumeric := true
+		allTuples := true
+		for _, item := range n.List {
+			if lit, ok := item.(*ast.Literal); ok {
+				if lit.Type != ast.LiteralInteger && lit.Type != ast.LiteralFloat {
+					allNumeric = false
+				}
+				if lit.Type != ast.LiteralTuple {
+					allTuples = false
+				}
+			} else {
+				allNumeric = false
+				allTuples = false
+				break
+			}
+		}
+		canBeTupleLiteral = allNumeric || allTuples
+	}
+
 	// Count arguments: expr + list items or subquery
 	argCount := 1
 	if n.Query != nil {
 		argCount++
+	} else if canBeTupleLiteral {
+		// Multiple literals will be combined into a single tuple
+		argCount++
 	} else {
 		// Check if we have a single tuple literal that should be wrapped in Function tuple
 		if len(n.List) == 1 {
@@ -198,10 +227,18 @@ func explainInExpr(sb *strings.Builder, n *ast.InExpr, indent string, depth int)
 	}
 	fmt.Fprintf(sb, "%s ExpressionList (children %d)\n", indent, argCount)
 	Node(sb, n.Expr, depth+2)
+
 	if n.Query != nil {
 		// Subqueries in IN should be wrapped in Subquery node
 		fmt.Fprintf(sb, "%s  Subquery (children %d)\n", indent, 1)
 		Node(sb, n.Query, depth+3)
+	} else if canBeTupleLiteral {
+		// Combine multiple literals into a single Tuple literal
+		tupleLit := &ast.Literal{
+			Type:  ast.LiteralTuple,
+			Value: n.List,
+		}
+		fmt.Fprintf(sb, "%s  Literal %s\n", indent, FormatLiteral(tupleLit))
 	} else if len(n.List) == 1 {
 		// Single element in the list
 		// If it's a tuple literal, wrap it in Function tuple

internal/explain/select.go

@@ -7,6 +7,13 @@ import (
 	"github.com/sqlc-dev/doubleclick/ast"
 )
 
+func explainSelectIntersectExceptQuery(sb *strings.Builder, n *ast.SelectIntersectExceptQuery, indent string, depth int) {
+	fmt.Fprintf(sb, "%sSelectIntersectExceptQuery (children %d)\n", indent, len(n.Selects))
+	for _, sel := range n.Selects {
+		Node(sb, sel, depth+1)
+	}
+}
+
 func explainSelectWithUnionQuery(sb *strings.Builder, n *ast.SelectWithUnionQuery, indent string, depth int) {
 	children := countSelectUnionChildren(n)
 	fmt.Fprintf(sb, "%sSelectWithUnionQuery (children %d)\n", indent, children)

internal/explain/statements.go

@@ -10,6 +10,12 @@ import (
 func explainInsertQuery(sb *strings.Builder, n *ast.InsertQuery, indent string, depth int) {
 	// Count children
 	children := 0
+	if n.Infile != "" {
+		children++
+	}
+	if n.Compression != "" {
+		children++
+	}
 	if n.Function != nil {
 		children++
 	} else if n.Table != "" {
@@ -24,6 +30,15 @@ func explainInsertQuery(sb *strings.Builder, n *ast.InsertQuery, indent string,
 	// Note: InsertQuery uses 3 spaces after name in ClickHouse explain
 	fmt.Fprintf(sb, "%sInsertQuery   (children %d)\n", indent, children)
 
+	// FROM INFILE path comes first
+	if n.Infile != "" {
+		fmt.Fprintf(sb, "%s Literal \\'%s\\'\n", indent, n.Infile)
+	}
+	// COMPRESSION value comes next
+	if n.Compression != "" {
+		fmt.Fprintf(sb, "%s Literal \\'%s\\'\n", indent, n.Compression)
+	}
+
 	if n.Function != nil {
 		Node(sb, n.Function, depth+1)
 	} else if n.Table != "" {

lexer/lexer.go

@@ -324,16 +324,26 @@ func (l *Lexer) readBlockComment() Item {
 	sb.WriteRune(l.ch)
 	l.readChar()
 
-	for !l.eof {
+	// Track nesting level for nested comments (ClickHouse supports nested /* */ comments)
+	nesting := 1
+
+	for !l.eof && nesting > 0 {
 		if l.ch == '*' && l.peekChar() == '/' {
 			sb.WriteRune(l.ch)
 			l.readChar()
 			sb.WriteRune(l.ch)
 			l.readChar()
-			break
+			nesting--
+		} else if l.ch == '/' && l.peekChar() == '*' {
+			sb.WriteRune(l.ch)
+			l.readChar()
+			sb.WriteRune(l.ch)
+			l.readChar()
+			nesting++
+		} else {
+			sb.WriteRune(l.ch)
+			l.readChar()
 		}
-		sb.WriteRune(l.ch)
-		l.readChar()
 	}
 	return Item{Token: token.COMMENT, Value: sb.String(), Pos: pos}
 }