lsp: local autocompletion #30

Author: vknabel

CHANGELOG.md

@@ -8,6 +8,7 @@
 - compiler: `import root` imports the current package (imports `src` if folder exists)
 - lsp: improved autocompletion and hover information
 - lsp: autocompletion and hover information across module and file boundaries
+- lsp: local autocompletion #30
 
 ## v0.0.15
 

README.md

@@ -26,7 +26,7 @@ Currently Lithia is an early proof of concept. Basic language features exist, bu
 - [x] Creating a custom language server
 - [x] ... with diagnostics
 - [x] ... with syntax highlighting
-- [ ] ... with auto completion _proof of concept_
+- [x] ... with auto completion _basic_
 - [ ] ... with highlights
 - [ ] ... with refactorings
 - [ ] ... with formatter
@@ -264,9 +264,26 @@ As shown, a common use case is to pass the module itself instead of multiple wit
 
 ### Module resolution
 
-Lithia will search for a folder containing source files at the following locations:
+To create your own package of modules, you can create a `Potfile`. Every module defined by the package is a directory next to the Potfile, with `.lithia` files in it.
+
+Though there are a few special cases:
+
+- the `cmd`-folder is typically used for individual files rather than a module. You execute them with `$ lithia cmd/<file>`.
+- the `src`-folder represents the `root` of the package.
+- if the `src`-folder is missing, the package `root` is next to the Potfile.
+
+```
+.
+├── Potfile
+├── cmd
+│   ├── main.lithia
+│   └── test.lithia
+└── src
+    └── greet.lithia
+```
+
+If there aren't any matching local modules, Lithia will search for a package containing source files at the following locations:
 
-- when executing a file, relative to it
 - when in REPL, inside the current working directory
 - at `$LITHIA_LOCALS` if set
 - at `$LITHIA_PACKAGES` if set

ast/context-file.go

@@ -48,3 +48,12 @@ func (sf *SourceFile) ExportedDeclarations() []Decl {
 	}
 	return decls
 }
+
+func (sf SourceFile) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	for _, decl := range sf.Declarations {
+		decl.EnumerateNestedDecls(enumerate)
+	}
+	for _, stmt := range sf.Statements {
+		stmt.EnumerateNestedDecls(enumerate)
+	}
+}

ast/decl-constant.go

@@ -40,3 +40,7 @@ func MakeDeclConstant(name Identifier, value Expr, source *Source) *DeclConstant
 func (e DeclConstant) ProvidedDocs() *Docs {
 	return e.Docs
 }
+
+func (e DeclConstant) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Value.EnumerateNestedDecls(enumerate)
+}

ast/decl-data.go

@@ -57,3 +57,7 @@ func (e *DeclData) AddField(field DeclField) {
 func (decl DeclData) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclData) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-enum-case.go

@@ -31,3 +31,7 @@ func MakeDeclEnumCase(name Identifier) *DeclEnumCase {
 func (decl DeclEnumCase) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclEnumCase) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-enum.go

@@ -69,3 +69,7 @@ func (e DeclEnum) String() string {
 func (decl DeclEnum) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (decl DeclEnum) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls - will be handled by the parser
+}

ast/decl-extern-func.go

@@ -50,3 +50,7 @@ func MakeDeclExternFunc(name Identifier, params []DeclParameter, source *Source)
 func (decl DeclExternFunc) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclExternFunc) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-extern-type.go

@@ -55,3 +55,7 @@ func (e *DeclExternType) AddField(decl DeclField) {
 func (decl DeclExternType) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclExternType) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-field.go

@@ -53,3 +53,7 @@ func MakeDeclField(name Identifier, params []DeclParameter, source *Source) *Dec
 func (decl DeclField) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclField) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-func.go

@@ -52,3 +52,7 @@ func MakeDeclFunc(name Identifier, impl *ExprFunc, source *Source) *DeclFunc {
 func (decl DeclFunc) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (decl DeclFunc) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	decl.Impl.EnumerateNestedDecls(enumerate)
+}

ast/decl-import-member.go

@@ -35,3 +35,7 @@ func MakeDeclImportMember(moduleName ModuleName, name Identifier, source *Source
 		MetaInfo:   &MetaDecl{source},
 	}
 }
+
+func (DeclImportMember) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-import.go

@@ -43,3 +43,7 @@ func MakeDeclImport(name ModuleName, source *Source) *DeclImport {
 		MetaInfo:   &MetaDecl{source},
 	}
 }
+
+func (DeclImport) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-module.go

@@ -35,3 +35,7 @@ func MakeDeclModule(internalName Identifier, source *Source) *DeclModule {
 func (decl DeclModule) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclModule) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl-parameter.go

@@ -33,3 +33,7 @@ func MakeDeclParameter(name Identifier, source *Source) *DeclParameter {
 func (decl DeclParameter) ProvidedDocs() *Docs {
 	return decl.Docs
 }
+
+func (DeclParameter) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/decl.go

@@ -4,4 +4,6 @@ type Decl interface {
 	DeclName() Identifier
 	IsExportedDecl() bool
 	Meta() *MetaDecl
+
+	EnumerateNestedDecls(enumerate func(interface{}, []Decl))
 }

ast/expr-array.go

@@ -20,3 +20,9 @@ func MakeExprArray(elements []Expr, source *Source) *ExprArray {
 		},
 	}
 }
+
+func (e ExprArray) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	for _, el := range e.Elements {
+		el.EnumerateNestedDecls(enumerate)
+	}
+}

ast/expr-float.go

@@ -11,3 +11,7 @@ type ExprFloat struct {
 func (e ExprFloat) Meta() *MetaExpr {
 	return e.MetaInfo
 }
+
+func (e ExprFloat) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/expr-func.go

@@ -32,3 +32,19 @@ func (e *ExprFunc) AddDecl(decl Decl) {
 func (e *ExprFunc) AddExpr(expr Expr) {
 	e.Expressions = append(e.Expressions, expr)
 }
+
+func (e ExprFunc) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	enumeratedDecls := make([]Decl, len(e.Parameters)+len(e.Declarations))
+	for i, param := range e.Parameters {
+		enumeratedDecls[i] = param
+	}
+	for i, decl := range e.Declarations {
+		decl.EnumerateNestedDecls(enumerate)
+		enumeratedDecls[len(e.Parameters)+i] = decl
+	}
+	enumerate(e, enumeratedDecls)
+
+	for _, expr := range e.Expressions {
+		expr.EnumerateNestedDecls(enumerate)
+	}
+}

ast/expr-group.go

@@ -18,3 +18,7 @@ func MakeExprGroup(expr Expr, source *Source) *ExprGroup {
 		MetaInfo: &MetaExpr{Source: source},
 	}
 }
+
+func (e ExprGroup) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Expr.EnumerateNestedDecls(enumerate)
+}

ast/expr-identifier.go

@@ -20,3 +20,7 @@ func MakeExprIdentifier(name Identifier, source *Source) *ExprIdentifier {
 		},
 	}
 }
+
+func (e ExprIdentifier) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/expr-int.go

@@ -20,3 +20,7 @@ func MakeExprInt(literal int64, source *Source) *ExprInt {
 		},
 	}
 }
+
+func (e ExprInt) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/expr-invocation.go

@@ -23,3 +23,11 @@ func MakeExprInvocation(function Expr, source *Source) *ExprInvocation {
 func (e *ExprInvocation) AddArgument(argument Expr) {
 	e.Arguments = append(e.Arguments, &argument)
 }
+
+func (e ExprInvocation) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Function.EnumerateNestedDecls(enumerate)
+
+	for _, arg := range e.Arguments {
+		(*arg).EnumerateNestedDecls(enumerate)
+	}
+}

ast/expr-member-access.go

@@ -22,3 +22,7 @@ func MakeExprMemberAccess(target Expr, accessPath []Identifier, source *Source)
 		},
 	}
 }
+
+func (e ExprMemberAccess) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Target.EnumerateNestedDecls(enumerate)
+}

ast/expr-operator-binary.go

@@ -24,3 +24,8 @@ func MakeExprOperatorBinary(operator OperatorBinary, left, right Expr, source *S
 		},
 	}
 }
+
+func (e ExprOperatorBinary) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Left.EnumerateNestedDecls(enumerate)
+	e.Right.EnumerateNestedDecls(enumerate)
+}

ast/expr-operator-unary.go

@@ -12,3 +12,7 @@ type ExprOperatorUnary struct {
 func (e ExprOperatorUnary) Meta() *MetaExpr {
 	return e.MetaInfo
 }
+
+func (e ExprOperatorUnary) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	(*e.Expr).EnumerateNestedDecls(enumerate)
+}

ast/expr-string.go

@@ -20,3 +20,7 @@ func MakeExprString(literal string, source *Source) *ExprString {
 		},
 	}
 }
+
+func (e ExprString) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	// no nested decls
+}

ast/expr-type-switch.go

@@ -29,3 +29,10 @@ func (e *ExprTypeSwitch) AddCase(key Identifier, value Expr) {
 	e.CaseOrder = append(e.CaseOrder, key)
 	e.Cases[key] = value
 }
+
+func (e ExprTypeSwitch) EnumerateNestedDecls(enumerate func(interface{}, []Decl)) {
+	e.Type.EnumerateNestedDecls(enumerate)
+	for _, ident := range e.CaseOrder {
+		e.Cases[ident].EnumerateNestedDecls(enumerate)
+	}
+}

ast/expr.go

@@ -2,4 +2,5 @@ package ast
 
 type Expr interface {
 	Meta() *MetaExpr
+	EnumerateNestedDecls(enumerate func(interface{}, []Decl))
 }

ast/meta-decl.go

@@ -3,3 +3,7 @@ package ast
 type MetaDecl struct {
 	*Source
 }
+
+func (m MetaDecl) SourceLocation() *Source {
+	return m.Source
+}

ast/meta-expr.go

@@ -3,3 +3,7 @@ package ast
 type MetaExpr struct {
 	Source *Source
 }
+
+func (m MetaExpr) SourceLocation() *Source {
+	return m.Source
+}

ast/meta.go

@@ -0,0 +1,5 @@
+package ast
+
+type Meta interface {
+	SourceLocation() *Source
+}

examples/greeter/cmd/main.lithia

@@ -1,3 +1,3 @@
-import package
+import root
 
-package.greet "World"
+root.greet "World"

langsrv/handler-completion.go

@@ -13,16 +13,20 @@ func textDocumentCompletion(context *glsp.Context, params *protocol.CompletionPa
 	rc := NewReqContextAtPosition(&params.TextDocumentPositionParams)
 
 	completionItems := []protocol.CompletionItem{}
-	for _, imported := range rc.globalDeclarations(context) {
+	for _, imported := range rc.accessibleDeclarations(context) {
 		insertText := insertTextForImportedDecl(imported)
 		var detail string
 		if imported.decl.Meta().ModuleName != "" {
 			detail = string(imported.decl.Meta().ModuleName) +
 				"." +
 				string(imported.decl.DeclName())
 		}
+		var importPrefix string
+		if imported.importDecl != nil {
+			importPrefix = fmt.Sprintf("%s.", imported.importDecl.DeclName())
+		}
 		completionItems = append(completionItems, protocol.CompletionItem{
-			Label:         string(imported.decl.DeclName()),
+			Label:         importPrefix + string(imported.decl.DeclName()),
 			Kind:          completionItemKindForDecl(imported.decl),
 			InsertText:    &insertText,
 			Detail:        &detail,

langsrv/handler-declaration.go

@@ -13,7 +13,7 @@ func textDocumentDeclaration(context *glsp.Context, params *protocol.Declaration
 		return nil, nil
 	}
 
-	for _, imported := range rc.globalDeclarations(context) {
+	for _, imported := range rc.accessibleDeclarations(context) {
 		if string(imported.decl.DeclName()) != token || imported.decl.Meta().Source == nil {
 			continue
 		}

langsrv/handler-definition.go

@@ -13,7 +13,7 @@ func textDocumentDefinition(context *glsp.Context, params *protocol.DefinitionPa
 		return nil, nil
 	}
 
-	for _, imported := range rc.globalDeclarations(context) {
+	for _, imported := range rc.accessibleDeclarations(context) {
 		decl := imported.decl
 		if string(decl.DeclName()) != token || decl.Meta().Source == nil {
 			continue

langsrv/handler-hover.go

@@ -13,7 +13,7 @@ func textDocumentHover(context *glsp.Context, params *protocol.HoverParams) (*pr
 		return nil, nil
 	}
 
-	for _, imported := range rc.globalDeclarations(context) {
+	for _, imported := range rc.accessibleDeclarations(context) {
 		decl := imported.decl
 		if string(decl.DeclName()) != name {
 			continue

langsrv/node-position-helpers.go

@@ -3,6 +3,7 @@ package langsrv
 import (
 	sitter "github.com/smacker/go-tree-sitter"
 	protocol "github.com/tliron/glsp/protocol_3_16"
+	"github.com/vknabel/lithia/ast"
 )
 
 func NodeAtPosition(node *sitter.Node, position protocol.Position) *sitter.Node {
@@ -62,3 +63,24 @@ func includesNodePosition(node *sitter.Node, position protocol.Position) bool {
 	}
 	return false
 }
+
+func includesAstSourcePosition(source *ast.Source, position protocol.Position) bool {
+	if source == nil {
+		return false
+	}
+	startRow := uint32(source.Start.Line)
+	startCol := uint32(source.Start.Column)
+	endRow := uint32(source.End.Line)
+	endCol := uint32(source.End.Column)
+
+	if startRow <= position.Line && endRow >= position.Line {
+		if startRow == position.Line && startCol > position.Character {
+			return false
+		}
+		if endRow == position.Line && endCol < position.Character {
+			return false
+		}
+		return true
+	}
+	return false
+}