invalidOp  = "invalid operation: "
)

// The positioner interface is used to extract the position of type-checker errors.
type positioner interface {
	Pos() token.Pos
}

func (check *Checker) error(at positioner, code Code, msg string) {
	err := check.newError(code)
	err.addf(at, "%s", msg)
	err.report()
}

func (check *Checker) errorf(at positioner, code Code, format string, args ...any) {

// dddErrPos returns the positioner for reporting an invalid ... use in a call.
func dddErrPos(call *ast.CallExpr) positioner { return atPos(call.Ellipsis) }

// argErrPos returns positioner for reporting an invalid argument count.
func argErrPos(call *ast.CallExpr) positioner { return inNode(call, call.Rparen) }

// startPos returns the start position of node n.
func startPos(n ast.Node) token.Pos { return n.Pos() }

//   - github.com/goplus/gox
//
// Do not remove or change the type signature.
// See go.dev/issue/67401.
//
//go:linkname badlinkname_Checker_infer go/types.(*Checker).infer

)

// allowVersion reports whether the current package at the given position
// is allowed to use version v. If the position is unknown, the specified
// module version (Config.GoVersion) is used. If that version is invalid,
// allowVersion returns true.
func (check *Checker) allowVersion(at positioner, v goVersion) bool {
	fileVersion := check.conf.GoVersion
	if pos := at.Pos(); pos.IsValid() {

			}
			continue // ignore
		}

		// The go/parser doesn't accept method type parameters but an ast.FuncType may have them.
		if sig.tparams != nil {
			var at positioner = f.Type
			if ftyp, _ := f.Type.(*ast.FuncType); ftyp != nil && ftyp.TypeParams != nil {
				at = ftyp.TypeParams
			}
			check.error(at, InvalidSyntaxTree, "methods cannot have type parameters")
		}

			return n.Pos()
		}
	}
}

// EndPos returns the approximate end position of n in the source.
// For some nodes (*Name, *BasicLit) it returns the position immediately
// following the node; for others (*BlockStmt, *SwitchStmt, etc.) it
// returns the position of the closing '}'; and for some (*ParenExpr)
// the returned position is the end position of the last enclosed
// expression.

		if fdecl, ok := decl.(*ast.FuncDecl); ok {
			ast.Walk(&Visitor{expectation, fset, t}, fdecl.Body)
		}
	}
	for ident, positions := range expectation {
		for _, position := range positions {
			if !position.Visited {
				t.Errorf("Position %d:%d missed for %s ident", position.Line, position.Column, ident)
			}
		}
	}

		// Get the filename, line, and column back via the file set.
		// We get both the relative and absolute position.
		// The relative position is relative to the last line directive.
		// The absolute position is the exact position in the source.
		pos := decl.Pos()
		relPosition := fset.Position(pos)
		absPosition := fset.PositionFor(pos, false)

		// Either a FuncDecl or GenDecl, since we exit on error.
		kind := "func"

func (p position_) String() string {
	if p.line == 0 {
		if p.filename == "" {
			return "<unknown position>"
		}
		return p.filename
	}
	if p.col == 0 {
		return fmt.Sprintf("%s:%d", p.filename, p.line)
	}
	return fmt.Sprintf("%s:%d:%d", p.filename, p.line, p.col)
}

// A PosBase represents the base for relative position information:
// At position pos, the relative position is filename:line:col.

// This file implements the compressed encoding of source
// positions using a lookup table.

package src

// XPos is a more compact representation of Pos.
type XPos struct {
	index int32
	lico
}

// NoXPos is a valid unknown position.
var NoXPos XPos

// IsKnown reports whether the position p is known.
// XPos.IsKnown() matches Pos.IsKnown() for corresponding
// positions.
func (p XPos) IsKnown() bool {