gopls/internal/span: simplify Span
This change moves span.Range to safetoken.Range, since it's in
the token domain. The span package now doesn't care about
the token domain (except for one testing-related hook).
Spans are now just a set of optional offset, line, and column,
any subset of which may be populated. All conversions between
these forms, or to other forms such as protocol or token,
are done by ColumnMapper. The With{Position,Offset,All} methods
and their redundant implementations of the conversion logic
(and the necessary workarounds) are gone.
Also:
- rename pgf.RangeToSpanRange to RangeToSpanRange.
- add ColumnMapper.PosLocation method
- typeErrorDiagnostics uses it, avoiding last call to span.FileSpan.
- delete span.FileSpan
- delete Span.Range method
- update TestFormat now that there is no "filling in" of
Spans based on a token.File.
Change-Id: I04000a1666d9e5333070dbbfac397f88bba23e11
Reviewed-on: https://go-review.googlesource.com/c/tools/+/460936
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Alan Donovan <adonovan@google.com>
Reviewed-by: Robert Findley <rfindley@google.com>
Auto-Submit: Alan Donovan <adonovan@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
diff --git a/gopls/internal/span/span.go b/gopls/internal/span/span.go
index 9687bbb..65c6e20 100644
--- a/gopls/internal/span/span.go
+++ b/gopls/internal/span/span.go
@@ -17,7 +17,17 @@
"golang.org/x/tools/gopls/internal/lsp/safetoken"
)
-// Span represents a source code range in standardized form.
+// A Span represents a range of text within a source file. The start
+// and end points of a valid span may be hold either its byte offset,
+// or its (line, column) pair, or both. Columns are measured in bytes.
+//
+// Spans are appropriate in user interfaces (e.g. command-line tools)
+// and tests where a position is notated without access to the content
+// of the file.
+//
+// Use protocol.ColumnMapper to convert between Span and other
+// representations, such as go/token (also UTF-8) or the LSP protocol
+// (UTF-16). The latter requires access to file contents.
type Span struct {
v span
}
@@ -29,6 +39,12 @@
v point
}
+// The private span/point types have public fields to support JSON
+// encoding, but the public Span/Point types hide these fields by
+// defining methods that shadow them. (This is used by a few of the
+// command-line tool subcommands, which emit spans and have a -json
+// flag.)
+
type span struct {
URI URI `json:"uri"`
Start point `json:"start"`
@@ -224,75 +240,6 @@
}
}
-// (Currently unused, but we gain little yet by deleting it.)
-func (s Span) withPosition(tf *token.File) (Span, error) {
- if err := s.update(tf, true, false); err != nil {
- return Span{}, err
- }
- return s, nil
-}
-
-func (s Span) withOffset(tf *token.File) (Span, error) {
- if err := s.update(tf, false, true); err != nil {
- return Span{}, err
- }
- return s, nil
-}
-
-// (Currently unused except by test.)
-func (s Span) WithAll(tf *token.File) (Span, error) {
- if err := s.update(tf, true, true); err != nil {
- return Span{}, err
- }
- return s, nil
-}
-
-func (s *Span) update(tf *token.File, withPos, withOffset bool) error {
- if !s.IsValid() {
- return fmt.Errorf("cannot add information to an invalid span")
- }
- if withPos && !s.HasPosition() {
- if err := s.v.Start.updatePosition(tf); err != nil {
- return err
- }
- if s.v.End.Offset == s.v.Start.Offset {
- s.v.End = s.v.Start
- } else if err := s.v.End.updatePosition(tf); err != nil {
- return err
- }
- }
- if withOffset && (!s.HasOffset() || (s.v.End.hasPosition() && !s.v.End.hasOffset())) {
- if err := s.v.Start.updateOffset(tf); err != nil {
- return err
- }
- if s.v.End.Line == s.v.Start.Line && s.v.End.Column == s.v.Start.Column {
- s.v.End.Offset = s.v.Start.Offset
- } else if err := s.v.End.updateOffset(tf); err != nil {
- return err
- }
- }
- return nil
-}
-
-func (p *point) updatePosition(tf *token.File) error {
- line, col8, err := offsetToLineCol8(tf, p.Offset)
- if err != nil {
- return err
- }
- p.Line = line
- p.Column = col8
- return nil
-}
-
-func (p *point) updateOffset(tf *token.File) error {
- offset, err := toOffset(tf, p.Line, p.Column)
- if err != nil {
- return err
- }
- p.Offset = offset
- return nil
-}
-
// SetRange implements packagestest.rangeSetter, allowing
// gopls' test suites to use Spans instead of Range in parameters.
func (span *Span) SetRange(file *token.File, start, end token.Pos) {
