gotools/gopls/internal/util/safetoken/safetoken.go

// Offset returns f.Offset(pos), but first checks that the file
// contains the pos.
//
// The definition of "contains" here differs from that of token.File
// in order to work around a bug in the parser (issue #57490): during
// error recovery, the parser may create syntax nodes whose computed
// End position is 1 byte beyond EOF, which would cause
// token.File.Offset to panic. The workaround is that this function
// accepts a Pos that is exactly 1 byte beyond EOF and maps it to the
// EOF offset.
func Offset(f *token.File, pos token.Pos) (int, error) { … }

// Offsets returns Offset(start) and Offset(end).
func Offsets(f *token.File, start, end token.Pos) (int, int, error) { … }

// Pos returns f.Pos(offset), but first checks that the offset is
// non-negative and not larger than the size of the file.
func Pos(f *token.File, offset int) (token.Pos, error) { … }

// inRange reports whether file f contains position pos,
// according to the invariants of token.File.
//
// This function is not public because of the ambiguity it would
// create w.r.t. the definition of "contains". Use Offset instead.
func inRange(f *token.File, pos token.Pos) bool { … }

// Position returns the Position for the pos value in the given file.
//
// p must be NoPos, a valid Pos in the range of f, or exactly 1 byte
// beyond the end of f. (See [Offset] for explanation.)
// Any other value causes a panic.
//
// Line directives (//line comments) are ignored.
func Position(f *token.File, pos token.Pos) token.Position { … }

// Line returns the line number for the given offset in the given file.
func Line(f *token.File, pos token.Pos) int { … }

// StartPosition converts a start Pos in the FileSet into a Position.
//
// Call this function only if start represents the start of a token or
// parse tree, such as the result of Node.Pos().  If start is the end of
// an interval, such as Node.End(), call EndPosition instead, as it
// may need the correction described at [Position].
func StartPosition(fset *token.FileSet, start token.Pos) (_ token.Position) { … }

// EndPosition converts an end Pos in the FileSet into a Position.
//
// Call this function only if pos represents the end of
// a non-empty interval, such as the result of Node.End().
func EndPosition(fset *token.FileSet, end token.Pos) (_ token.Position) { … }