blob: 7028101fb517b0aff8d13d9d02ad9a9e6d219ec2 [file] [log] [blame]
// 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.
package lsp
import (
"context"
"fmt"
"sort"
"strings"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/span"
)
func (s *Server) completion(ctx context.Context, params *protocol.CompletionParams) (*protocol.CompletionList, error) {
uri := span.NewURI(params.TextDocument.URI)
view := s.findView(ctx, uri)
f, m, err := newColumnMap(ctx, view, uri)
if err != nil {
return nil, err
}
spn, err := m.PointSpan(params.Position)
if err != nil {
return nil, err
}
rng, err := spn.Range(m.Converter)
if err != nil {
return nil, err
}
items, prefix, err := source.Completion(ctx, f, rng.Start)
if err != nil {
s.log.Infof(ctx, "no completions found for %s:%v:%v: %v", uri, int(params.Position.Line), int(params.Position.Character), err)
items = []source.CompletionItem{}
}
return &protocol.CompletionList{
IsIncomplete: false,
Items: toProtocolCompletionItems(items, prefix, params.Position, s.insertTextFormat, s.usePlaceholders),
}, nil
}
func toProtocolCompletionItems(candidates []source.CompletionItem, prefix string, pos protocol.Position, insertTextFormat protocol.InsertTextFormat, usePlaceholders bool) []protocol.CompletionItem {
sort.SliceStable(candidates, func(i, j int) bool {
return candidates[i].Score > candidates[j].Score
})
items := []protocol.CompletionItem{}
for i, candidate := range candidates {
// Match against the label.
if !strings.HasPrefix(candidate.Label, prefix) {
continue
}
insertText := candidate.InsertText
if insertTextFormat == protocol.SnippetTextFormat {
if usePlaceholders && candidate.PlaceholderSnippet != nil {
insertText = candidate.PlaceholderSnippet.String()
} else if candidate.Snippet != nil {
insertText = candidate.Snippet.String()
}
}
// If the user has already typed some part of the completion candidate,
// don't insert that portion of the text.
if strings.HasPrefix(insertText, prefix) {
insertText = insertText[len(prefix):]
}
// Don't filter on text that might have snippets in it.
filterText := candidate.InsertText
if strings.HasPrefix(filterText, prefix) {
filterText = filterText[len(prefix):]
}
item := protocol.CompletionItem{
Label: candidate.Label,
Detail: candidate.Detail,
Kind: toProtocolCompletionItemKind(candidate.Kind),
TextEdit: &protocol.TextEdit{
NewText: insertText,
Range: protocol.Range{
Start: pos,
End: pos,
},
},
InsertTextFormat: insertTextFormat,
// This is a hack so that the client sorts completion results in the order
// according to their score. This can be removed upon the resolution of
// https://github.com/Microsoft/language-server-protocol/issues/348.
SortText: fmt.Sprintf("%05d", i),
FilterText: filterText,
Preselect: i == 0,
}
// Trigger signature help for any function or method completion.
// This is helpful even if a function does not have parameters,
// since we show return types as well.
switch item.Kind {
case protocol.FunctionCompletion, protocol.MethodCompletion:
item.Command = &protocol.Command{
Command: "editor.action.triggerParameterHints",
}
}
items = append(items, item)
}
return items
}
func toProtocolCompletionItemKind(kind source.CompletionItemKind) protocol.CompletionItemKind {
switch kind {
case source.InterfaceCompletionItem:
return protocol.InterfaceCompletion
case source.StructCompletionItem:
return protocol.StructCompletion
case source.TypeCompletionItem:
return protocol.TypeParameterCompletion // ??
case source.ConstantCompletionItem:
return protocol.ConstantCompletion
case source.FieldCompletionItem:
return protocol.FieldCompletion
case source.ParameterCompletionItem, source.VariableCompletionItem:
return protocol.VariableCompletion
case source.FunctionCompletionItem:
return protocol.FunctionCompletion
case source.MethodCompletionItem:
return protocol.MethodCompletion
case source.PackageCompletionItem:
return protocol.ModuleCompletion // ??
default:
return protocol.TextCompletion
}
}