Introduce TypelessStructLiteralArg and NewConstructorArg interfaces

ast/ast.go

@@ -150,38 +150,43 @@ type Expr interface {
 	isExpr()
 }
 
-func (BinaryExpr) isExpr()       {}
-func (UnaryExpr) isExpr()        {}
-func (InExpr) isExpr()           {}
-func (IsNullExpr) isExpr()       {}
-func (IsBoolExpr) isExpr()       {}
-func (BetweenExpr) isExpr()      {}
-func (SelectorExpr) isExpr()     {}
-func (IndexExpr) isExpr()        {}
-func (CallExpr) isExpr()         {}
-func (CountStarExpr) isExpr()    {}
-func (CastExpr) isExpr()         {}
-func (ExtractExpr) isExpr()      {}
-func (CaseExpr) isExpr()         {}
-func (ParenExpr) isExpr()        {}
-func (ScalarSubQuery) isExpr()   {}
-func (ArraySubQuery) isExpr()    {}
-func (ExistsSubQuery) isExpr()   {}
-func (Param) isExpr()            {}
-func (Ident) isExpr()            {}
-func (Path) isExpr()             {}
-func (ArrayLiteral) isExpr()     {}
-func (StructLiteral) isExpr()    {}
-func (NullLiteral) isExpr()      {}
-func (BoolLiteral) isExpr()      {}
-func (IntLiteral) isExpr()       {}
-func (FloatLiteral) isExpr()     {}
-func (StringLiteral) isExpr()    {}
-func (BytesLiteral) isExpr()     {}
-func (DateLiteral) isExpr()      {}
-func (TimestampLiteral) isExpr() {}
-func (NumericLiteral) isExpr()   {}
-func (JSONLiteral) isExpr()      {}
+func (BinaryExpr) isExpr()            {}
+func (UnaryExpr) isExpr()             {}
+func (InExpr) isExpr()                {}
+func (IsNullExpr) isExpr()            {}
+func (IsBoolExpr) isExpr()            {}
+func (BetweenExpr) isExpr()           {}
+func (SelectorExpr) isExpr()          {}
+func (IndexExpr) isExpr()             {}
+func (CallExpr) isExpr()              {}
+func (CountStarExpr) isExpr()         {}
+func (CastExpr) isExpr()              {}
+func (ExtractExpr) isExpr()           {}
+func (CaseExpr) isExpr()              {}
+func (ParenExpr) isExpr()             {}
+func (ScalarSubQuery) isExpr()        {}
+func (ArraySubQuery) isExpr()         {}
+func (ExistsSubQuery) isExpr()        {}
+func (Param) isExpr()                 {}
+func (Ident) isExpr()                 {}
+func (Path) isExpr()                  {}
+func (ArrayLiteral) isExpr()          {}
+func (TupleStructLiteral) isExpr()    {}
+func (TypelessStructLiteral) isExpr() {}
+func (TypedStructLiteral) isExpr()    {}
+func (NullLiteral) isExpr()           {}
+func (BoolLiteral) isExpr()           {}
+func (IntLiteral) isExpr()            {}
+func (FloatLiteral) isExpr()          {}
+func (StringLiteral) isExpr()         {}
+func (BytesLiteral) isExpr()          {}
+func (DateLiteral) isExpr()           {}
+func (TimestampLiteral) isExpr()      {}
+func (NumericLiteral) isExpr()        {}
+func (JSONLiteral) isExpr()           {}
+func (NewConstructor) isExpr()        {}
+func (BracedNewConstructor) isExpr()  {}
+func (BracedConstructor) isExpr()     {}
 
 // Arg represents argument of function call.
 type Arg interface {
@@ -221,6 +226,24 @@ func (UnnestInCondition) isInCondition()   {}
 func (SubQueryInCondition) isInCondition() {}
 func (ValuesInCondition) isInCondition()   {}
 
+// TypelessStructLiteralArg represents an argument of typeless STRUCT literals.
+type TypelessStructLiteralArg interface {
+	Node
+	isTypelessStructLiteralArg()
+}
+
+func (ExprArg) isTypelessStructLiteralArg() {}
+func (Alias) isTypelessStructLiteralArg()   {}
+
+// NewConstructorArg represents an argument of NEW constructors.
+type NewConstructorArg interface {
+	Node
+	isNewConstructorArg()
+}
+
+func (ExprArg) isNewConstructorArg() {}
+func (Alias) isNewConstructorArg()   {}
+
 // Type represents type node.
 type Type interface {
 	Node
@@ -607,7 +630,10 @@ type DotStar struct {
 	Expr Expr
 }
 
-// Alias is aliased expression by AS clause in SELECT result columns list.
+// Alias is aliased expression by AS clause.
+//
+// Typically, this appears in SELECT result columns list, but this can appear in typeless STRUCT literals
+// and NEW constructors.
 //
 //	{{.Expr | sql}} {{.As | sql}}
 type Alias struct {
@@ -622,16 +648,12 @@ type Alias struct {
 //
 // It is used in Alias node and some JoinExpr nodes.
 //
-// NOTE: Sometime keyword AS can be omited.
-//
-//	  In this case, it.token.Pos() == it.Alias.token.Pos(), so we can detect this.
-//
-//	AS {{.Alias | sql}}
+//	{{if not .As.Invalid}}AS {{end}}{{.Alias | sql}}
 type AsAlias struct {
 	// pos = As || Alias.pos
 	// end = Alias.end
 
-	As token.Pos // position of "AS" keyword
+	As token.Pos // position of "AS" keyword, optional
 
 	Alias *Ident
 }
@@ -1376,22 +1398,45 @@ type ArrayLiteral struct {
 	Values []Expr
 }
 
-// StructLiteral is struct literal node.
+// TupleStructLiteral is tuple syntax struct literal node.
 //
-//	STRUCT{{if not (isnil .Fields)}}<{{.Fields | sqlJoin ","}}>{{end}}({{.Values | sqlJoin ","}})
-type StructLiteral struct {
-	// pos = Struct || Lparen
+//	({{.Values | sqlJoin ","}})
+type TupleStructLiteral struct {
+	// pos = Lparen
 	// end = Rparen + 1
 
-	Struct         token.Pos // position of "STRUCT"
 	Lparen, Rparen token.Pos // position of "(" and ")"
 
-	// NOTE: Distinguish nil from len(Fields) == 0 case.
-	//       nil means type is not specified, or empty slice means this struct has 0 fields.
+	Values []Expr // len(Values) > 1
+}
+
+// TypedStructLiteral is typed struct literal node.
+//
+//	STRUCT<{{.Fields | sqlJoin ","}}>({{.Values | sqlJoin ","}})
+type TypedStructLiteral struct {
+	// pos = Struct
+	// end = Rparen + 1
+
+	Struct token.Pos // position of "STRUCT"
+	Rparen token.Pos // position of ")"
+
 	Fields []*StructField
 	Values []Expr
 }
 
+// TypelessStructLiteral is typeless struct literal node.
+//
+//	STRUCT({{.Values | sqlJoin ","}})
+type TypelessStructLiteral struct {
+	// pos = Struct
+	// end = Rparen + 1
+
+	Struct token.Pos // position of "STRUCT"
+	Rparen token.Pos // position of ")"
+
+	Values []TypelessStructLiteralArg
+}
+
 // NullLiteral is just NULL literal.
 //
 //	NULL
@@ -1511,6 +1556,85 @@ type JSONLiteral struct {
 	Value *StringLiteral
 }
 
+// ================================================================================
+//
+// NEW constructors
+//
+// ================================================================================
+
+// BracedConstructorFieldValue represents value part of fields in BracedNewConstructor.
+type BracedConstructorFieldValue interface {
+	Node
+	isBracedConstructorFieldValue()
+}
+
+func (*BracedConstructor) isBracedConstructorFieldValue()               {}
+func (*BracedConstructorFieldValueExpr) isBracedConstructorFieldValue() {}
+
+// NewConstructor represents NEW operator which creates a protocol buffer using a parenthesized list of arguments.
+//
+//	NEW {{.Type | sql}} ({{.Args | sqlJoin ", "}})
+type NewConstructor struct {
+	// pos = New
+	// end = Rparen + 1
+
+	New  token.Pos
+	Type *NamedType
+
+	Args []NewConstructorArg
+
+	Rparen token.Pos
+}
+
+// BracedNewConstructor represents NEW operator which creates a protocol buffer using a map constructor.
+//
+//	NEW {{.Type | sql}} {{"{"}}{{"}"}}
+type BracedNewConstructor struct {
+	// pos = New
+	// end = Body.end
+
+	New token.Pos
+
+	Type *NamedType
+	Body *BracedConstructor
+}
+
+// BracedConstructor represents a single map constructor which is used in BracedNewConstructor.
+// Actually, it is a top level Expr in syntax, but it is not permitted semantically in other place.
+//
+//	{{"{"}}{{.Fields | sqlJoin ", "}}{{"}"}}
+type BracedConstructor struct {
+	// pos = Lbrace
+	// end = Rbrace + 1
+
+	Lbrace, Rbrace token.Pos
+
+	Fields []*BracedConstructorField
+}
+
+// BracedConstructorField represents a single field in BracedConstructor.
+//
+//	{{.Name | sql}} {{.Value | sql}}
+type BracedConstructorField struct {
+	// pos = Name.pos
+	// end = Value.end
+
+	Name  *Ident
+	Value BracedConstructorFieldValue
+}
+
+// BracedConstructorFieldValueExpr represents a field value node.
+//
+//	: {{.Expr | sql}}
+type BracedConstructorFieldValueExpr struct {
+	// pos = Colon
+	// end = Expr.end
+
+	Colon token.Pos
+
+	Expr Expr
+}
+
 // ================================================================================
 //
 // Type

ast/ast_test.go

@@ -87,7 +87,7 @@ func TestExpr(t *testing.T) {
 	Expr(&Ident{}).isExpr()
 	Expr(&Path{}).isExpr()
 	Expr(&ArrayLiteral{}).isExpr()
-	Expr(&StructLiteral{}).isExpr()
+	Expr(&TypedStructLiteral{}).isExpr()
 	Expr(&NullLiteral{}).isExpr()
 	Expr(&BoolLiteral{}).isExpr()
 	Expr(&IntLiteral{}).isExpr()