// ----------------------------------------------------------------------------
// Implementation

// funcType type-checks a function or method type.
func (check *Checker) funcType(sig *Signature, recvPar *syntax.Field, tparams []*syntax.Field, ftyp *syntax.FuncType) {
	check.openScope(ftyp, "function")
	check.scope.isFunc = true
	check.recordScope(ftyp, check.scope)
	sig.scope = check.scope

		// Uniquely, FuncDecl breaks the invariant that
		// preorder traversal yields tokens in lexical order:
		// in fact, FuncDecl.Recv precedes FuncDecl.Type.Func.
		//
		// As a workaround, we inline the case for FuncType
		// here and order things correctly.
		//
		children = nil // discard ast.Walk(FuncDecl) info subtrees
		children = append(children, tok(n.Type.Func, len("func")))
		if n.Recv != nil {

		if i > 0 {
			s += "; "
		}
		s += v.Name + "=" + strconv.FormatInt(v.Val, 10)
	}
	s += "}"
	return s
}

// A FuncType represents a function type.
type FuncType struct {
	CommonType
	ReturnType Type
	ParamType  []Type
}

func (t *FuncType) String() string {
	s := "func("
	for i, t := range t.ParamType {
		if i > 0 {
			s += ", "
		}
		s += t.String()
	}
	s += ")"

	return abi.TFlag(p[abi.TFlagOff(arch.PtrSize)])&abi.TFlagUncommon != 0
}

// Type.FuncType.dotdotdot
func decodetypeFuncDotdotdot(arch *sys.Arch, p []byte) bool {
	return uint16(decodeInuxi(arch, p[commonsize(arch)+2:], 2))&(1<<15) != 0
}

// Type.FuncType.inCount
func decodetypeFuncInCount(arch *sys.Arch, p []byte) int {
	return int(decodeInuxi(arch, p[commonsize(arch):], 2))
}

//         Elem typeOff
//     }
//
//     type MapType struct {
//         Tag  itag // mapType
//         Key  typeOff
//         Elem typeOff
//     }
//
//     type FuncType struct {
//         Tag       itag // signatureType
//         PkgPath   stringOff
//         Signature Signature
//     }
//
//     type StructType struct {
//         Tag     itag // structType

pkg p1, type Embedded struct
pkg p1, type Error interface { Error, Temporary }
pkg p1, type Error interface, Error() string
pkg p1, type Error interface, Temporary() bool
pkg p1, type FuncType func(int, int, string) (*B, error)
pkg p1, type I interface, Get(string) int64
pkg p1, type I interface, Get //deprecated
pkg p1, type I interface, GetNamed(string) int64
pkg p1, type I interface, Name() string

	case *ast.File:
		return 1 << nFile
	case *ast.ForStmt:
		return 1 << nForStmt
	case *ast.FuncDecl:
		return 1 << nFuncDecl
	case *ast.FuncLit:
		return 1 << nFuncLit
	case *ast.FuncType:
		return 1 << nFuncType
	case *ast.GenDecl:
		return 1 << nGenDecl
	case *ast.GoStmt:
		return 1 << nGoStmt
	case *ast.Ident:
		return 1 << nIdent
	case *ast.IfStmt:
		return 1 << nIfStmt

	//     12  .  .  .  .  .  Kind: func
	//     13  .  .  .  .  .  Name: "main"
	//     14  .  .  .  .  .  Decl: *(obj @ 7)
	//     15  .  .  .  .  }
	//     16  .  .  .  }
	//     17  .  .  .  Type: *ast.FuncType {
	//     18  .  .  .  .  Func: 3:1
	//     19  .  .  .  .  Params: *ast.FieldList {
	//     20  .  .  .  .  .  Opening: 3:10
	//     21  .  .  .  .  .  Closing: 3:11
	//     22  .  .  .  .  }
	//     23  .  .  .  }

		dir := "types.Cboth"
		switch t.Dir {
		case ast.SEND:
			dir = "types.Csend"
		case ast.RECV:
			dir = "types.Crecv"
		}
		return fmt.Sprintf("types.NewChan(%s, %s)", i.subtype(t.Value), dir)
	case *ast.FuncType:
		return fmt.Sprintf("newSig(%s, %s)", i.fields(t.Params, false), i.fields(t.Results, false))
	case *ast.InterfaceType:
		if len(t.Methods.List) != 0 {
			log.Fatal("non-empty interfaces unsupported")
		}

	case **ast.BlockStmt:
		walkBeforeAfter(*n, before, after)
	case **ast.CallExpr:
		walkBeforeAfter(*n, before, after)
	case **ast.FieldList:
		walkBeforeAfter(*n, before, after)
	case **ast.FuncType:
		walkBeforeAfter(*n, before, after)
	case **ast.Ident:
		walkBeforeAfter(*n, before, after)
	case **ast.BasicLit:
		walkBeforeAfter(*n, before, after)

	// pointers to slices
	case *[]ast.Decl: