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// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// this file contains protocol<->span converters
package protocol
import (
"fmt"
"go/token"
"golang.org/x/tools/internal/span"
)
// A ColumnMapper maps between UTF-8 oriented positions (e.g. token.Pos,
// span.Span) and the UTF-16 oriented positions used by the LSP.
type ColumnMapper struct {
URI span.URI
TokFile *token.File
Content []byte
}
// NewColumnMapper creates a new column mapper for the given uri and content.
func NewColumnMapper(uri span.URI, content []byte) *ColumnMapper {
tf := span.NewTokenFile(uri.Filename(), content)
return &ColumnMapper{
URI: uri,
TokFile: tf,
Content: content,
}
}
func URIFromSpanURI(uri span.URI) DocumentURI {
return DocumentURI(uri)
}
func URIFromPath(path string) DocumentURI {
return URIFromSpanURI(span.URIFromPath(path))
}
func (u DocumentURI) SpanURI() span.URI {
return span.URIFromURI(string(u))
}
func (m *ColumnMapper) Location(s span.Span) (Location, error) {
rng, err := m.Range(s)
if err != nil {
return Location{}, err
}
return Location{URI: URIFromSpanURI(s.URI()), Range: rng}, nil
}
func (m *ColumnMapper) Range(s span.Span) (Range, error) {
if span.CompareURI(m.URI, s.URI()) != 0 {
return Range{}, fmt.Errorf("column mapper is for file %q instead of %q", m.URI, s.URI())
}
s, err := s.WithAll(m.TokFile)
if err != nil {
return Range{}, err
}
start, err := m.Position(s.Start())
if err != nil {
return Range{}, err
}
end, err := m.Position(s.End())
if err != nil {
return Range{}, err
}
return Range{Start: start, End: end}, nil
}
func (m *ColumnMapper) Position(p span.Point) (Position, error) {
chr, err := span.ToUTF16Column(p, m.Content)
if err != nil {
return Position{}, err
}
return Position{
Line: uint32(p.Line() - 1),
Character: uint32(chr - 1),
}, nil
}
func (m *ColumnMapper) Span(l Location) (span.Span, error) {
return m.RangeSpan(l.Range)
}
func (m *ColumnMapper) RangeSpan(r Range) (span.Span, error) {
start, err := m.Point(r.Start)
if err != nil {
return span.Span{}, err
}
end, err := m.Point(r.End)
if err != nil {
return span.Span{}, err
}
return span.New(m.URI, start, end).WithAll(m.TokFile)
}
func (m *ColumnMapper) RangeToSpanRange(r Range) (span.Range, error) {
spn, err := m.RangeSpan(r)
if err != nil {
return span.Range{}, err
}
return spn.Range(m.TokFile)
}
// Pos returns the token.Pos of p within the mapped file.
func (m *ColumnMapper) Pos(p Position) (token.Pos, error) {
start, err := m.Point(p)
if err != nil {
return token.NoPos, err
}
// TODO: refactor the span package to avoid creating this unnecessary end position.
spn, err := span.New(m.URI, start, start).WithAll(m.TokFile)
if err != nil {
return token.NoPos, err
}
rng, err := spn.Range(m.TokFile)
if err != nil {
return token.NoPos, err
}
return rng.Start, nil
}
// Offset returns the utf-8 byte offset of p within the mapped file.
func (m *ColumnMapper) Offset(p Position) (int, error) {
start, err := m.Point(p)
if err != nil {
return 0, err
}
return start.Offset(), nil
}
// Point returns a span.Point for p within the mapped file. The resulting point
// always has an Offset.
func (m *ColumnMapper) Point(p Position) (span.Point, error) {
line := int(p.Line) + 1
offset, err := span.ToOffset(m.TokFile, line, 1)
if err != nil {
return span.Point{}, err
}
lineStart := span.NewPoint(line, 1, offset)
return span.FromUTF16Column(lineStart, int(p.Character)+1, m.Content)
}
func IsPoint(r Range) bool {
return r.Start.Line == r.End.Line && r.Start.Character == r.End.Character
}
func CompareRange(a, b Range) int {
if r := ComparePosition(a.Start, b.Start); r != 0 {
return r
}
return ComparePosition(a.End, b.End)
}
func ComparePosition(a, b Position) int {
if a.Line < b.Line {
return -1
}
if a.Line > b.Line {
return 1
}
if a.Character < b.Character {
return -1
}
if a.Character > b.Character {
return 1
}
return 0
}
func Intersect(a, b Range) bool {
if a.Start.Line > b.End.Line || a.End.Line < b.Start.Line {
return false
}
return !((a.Start.Line == b.End.Line) && a.Start.Character > b.End.Character ||
(a.End.Line == b.Start.Line) && a.End.Character < b.Start.Character)
}
func (r Range) Format(f fmt.State, _ rune) {
fmt.Fprintf(f, "%v:%v-%v:%v", r.Start.Line, r.Start.Character, r.End.Line, r.End.Character)
}