internal/lsp: add basic support for hover
This change adds a very simple implementation of hovering. It doesn't
show any documentation, just the object string for the given object.
Also, this change sets the prefix for composite literals, making sure we
don't insert duplicate text.
Change-Id: Ib706ec821a9e459a6c61c10f5dd28d1798944fa3
Reviewed-on: https://go-review.googlesource.com/c/152599
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/internal/lsp/server.go b/internal/lsp/server.go
index b8b0952..30c7417 100644
--- a/internal/lsp/server.go
+++ b/internal/lsp/server.go
@@ -57,6 +57,7 @@
DefinitionProvider: true,
DocumentFormattingProvider: true,
DocumentRangeFormattingProvider: true,
+ HoverProvider: true,
SignatureHelpProvider: protocol.SignatureHelpOptions{
TriggerCharacters: []string{"(", ","},
},
@@ -184,8 +185,24 @@
return nil, notImplemented("CompletionResolve")
}
-func (s *server) Hover(context.Context, *protocol.TextDocumentPositionParams) (*protocol.Hover, error) {
- return nil, notImplemented("Hover")
+func (s *server) Hover(ctx context.Context, params *protocol.TextDocumentPositionParams) (*protocol.Hover, error) {
+ f := s.view.GetFile(source.URI(params.TextDocument.URI))
+ tok, err := f.GetToken()
+ if err != nil {
+ return nil, err
+ }
+ pos := fromProtocolPosition(tok, params.Position)
+ contents, rng, err := source.Hover(ctx, f, pos)
+ if err != nil {
+ return nil, err
+ }
+ return &protocol.Hover{
+ Contents: protocol.MarkupContent{
+ Kind: protocol.Markdown,
+ Value: contents,
+ },
+ Range: toProtocolRange(tok, rng),
+ }, nil
}
func (s *server) SignatureHelp(ctx context.Context, params *protocol.TextDocumentPositionParams) (*protocol.SignatureHelp, error) {
diff --git a/internal/lsp/source/completion.go b/internal/lsp/source/completion.go
index 5f8e3d8..5524de2 100644
--- a/internal/lsp/source/completion.go
+++ b/internal/lsp/source/completion.go
@@ -101,8 +101,8 @@
}
// The position is within a composite literal.
- if items, ok := complit(path, pos, pkg, info, found); ok {
- return items, "", nil
+ if items, prefix, ok := complit(path, pos, pkg, info, found); ok {
+ return items, prefix, nil
}
switch n := path[0].(type) {
case *ast.Ident:
@@ -250,7 +250,7 @@
// complit finds completions for field names inside a composite literal.
// It reports whether the node was handled as part of a composite literal.
-func complit(path []ast.Node, pos token.Pos, pkg *types.Package, info *types.Info, found finder) (items []CompletionItem, ok bool) {
+func complit(path []ast.Node, pos token.Pos, pkg *types.Package, info *types.Info, found finder) (items []CompletionItem, prefix string, ok bool) {
var lit *ast.CompositeLit
// First, determine if the pos is within a composite literal.
@@ -286,6 +286,8 @@
}
}
case *ast.Ident:
+ prefix = n.Name[:pos-n.Pos()]
+
// If the enclosing node is an identifier, it can either be an identifier that is
// part of a composite literal (e.g. &x{fo<>}), or it can be an identifier that is
// part of a key-value expression, which is part of a composite literal (e.g. &x{foo: ba<>).
@@ -311,7 +313,7 @@
}
// We are not in a composite literal.
if lit == nil {
- return nil, false
+ return nil, prefix, false
}
// Mark fields of the composite literal that have already been set,
// except for the current field.
@@ -351,10 +353,10 @@
if !hasKeys && structPkg == pkg {
items = append(items, lexical(path, pos, pkg, info, found)...)
}
- return items, true
+ return items, prefix, true
}
}
- return items, false
+ return items, prefix, false
}
// formatCompletion creates a completion item for a given types.Object.
diff --git a/internal/lsp/source/definition.go b/internal/lsp/source/definition.go
index b4f05f4..7990325 100644
--- a/internal/lsp/source/definition.go
+++ b/internal/lsp/source/definition.go
@@ -30,7 +30,7 @@
return Range{}, err
}
if i.ident == nil {
- return Range{}, fmt.Errorf("definition was not a valid identifier")
+ return Range{}, fmt.Errorf("not a valid identifier")
}
obj := pkg.TypesInfo.ObjectOf(i.ident)
if obj == nil {
diff --git a/internal/lsp/source/hover.go b/internal/lsp/source/hover.go
new file mode 100644
index 0000000..2c04a88
--- /dev/null
+++ b/internal/lsp/source/hover.go
@@ -0,0 +1,50 @@
+// 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 source
+
+import (
+ "context"
+ "fmt"
+ "go/token"
+ "go/types"
+)
+
+func Hover(ctx context.Context, f *File, pos token.Pos) (string, Range, error) {
+ fAST, err := f.GetAST()
+ if err != nil {
+ return "", Range{}, err
+ }
+ pkg, err := f.GetPackage()
+ if err != nil {
+ return "", Range{}, err
+ }
+ i, err := findIdentifier(fAST, pos)
+ if err != nil {
+ return "", Range{}, err
+ }
+ if i.ident == nil {
+ return "", Range{}, fmt.Errorf("not a valid identifier")
+ }
+ obj := pkg.TypesInfo.ObjectOf(i.ident)
+ if obj == nil {
+ return "", Range{}, fmt.Errorf("no object")
+ }
+ if i.wasEmbeddedField {
+ // the original position was on the embedded field declaration
+ // so we try to dig out the type and jump to that instead
+ if v, ok := obj.(*types.Var); ok {
+ if n, ok := v.Type().(*types.Named); ok {
+ obj = n.Obj()
+ }
+ }
+ }
+ // TODO(rstambler): Add documentation and improve quality of object string.
+ content := types.ObjectString(obj, qualifier(fAST, pkg.Types, pkg.TypesInfo))
+ markdown := "```go\n" + content + "\n```"
+ return markdown, Range{
+ Start: i.ident.Pos(),
+ End: i.ident.End(),
+ }, nil
+}
