internal/typeparams: remove examples in favor of x/exp/typeparams
The internal/typeparams directory contains an initial draft of the
documentation later published under the golang.org/x/exp/typeparams
module. Remove this draft to avoid confusion.
Change-Id: I1f40468f99c0d2885e8fc380c75669f654ba971e
Reviewed-on: https://go-review.googlesource.com/c/tools/+/405260
Reviewed-by: Alan Donovan <adonovan@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>
diff --git a/internal/typeparams/common.go b/internal/typeparams/common.go
index f7678d3..25a1426 100644
--- a/internal/typeparams/common.go
+++ b/internal/typeparams/common.go
@@ -16,11 +16,10 @@
// Additionally, this package contains common utilities for working with the
// new generic constructs, to supplement the standard library APIs. Notably,
// the StructuralTerms API computes a minimal representation of the structural
-// restrictions on a type parameter. In the future, this API may be available
-// from go/types.
+// restrictions on a type parameter.
//
-// See the example/README.md for a more detailed guide on how to update tools
-// to support generics.
+// An external version of these APIs is available in the
+// golang.org/x/exp/typeparams module.
package typeparams
import (
diff --git a/internal/typeparams/example/README.md b/internal/typeparams/example/README.md
deleted file mode 100644
index 9877735..0000000
--- a/internal/typeparams/example/README.md
+++ /dev/null
@@ -1,328 +0,0 @@
-<!-- Autogenerated by weave; DO NOT EDIT -->
-<!-- To regenerate the readme, run: -->
-<!-- go run golang.org/x/example/gotypes@latest generic-go-types.md -->
-
-# Updating tools to support type parameters.
-
-This guide is maintained by Rob Findley (`rfindley@google.com`).
-
-**status**: this document is currently a work-in-progress. See
-[golang/go#50447](https://go.dev/issues/50447) for more details.
-
-1. [Introduction](#introduction)
-1. [Summary of new language features and their APIs](#summary-of-new-language-features-and-their-apis)
-1. [Examples](#examples)
- 1. [Generic types](#generic-types)
- 1. [Constraint Interfaces](#constraint-interfaces)
- 1. [Instantiation](#instantiation)
-1. [Updating tools while building at older Go versions](#updating-tools-while-building-at-older-go-versions)
-1. [Further help](#further-help)
-
-# Introduction
-
-With Go 1.18, Go now supports generic programming via type parameters. This
-document is intended to serve as a guide for tool authors that want to update
-their tools to support the new language constructs introduced for generic Go.
-
-This guide assumes some knowledge of the language changes to support generics.
-See the following references for more information:
-
-- The [original proposal](https://go.dev/issue/43651) for type parameters.
-- The [addendum for type sets](https://go.dev/issue/45346).
-- The [latest language specfication](https://tip.golang.org/ref/spec) (still in-progress as of 2021-01-11).
-- The proposals for new APIs in
- [go/token and go/ast](https://go.dev/issue/47781), and in
- [go/types](https://go.dev/issue/47916).
-
-It also assumes existing knowledge of `go/ast` and `go/types`. If you're just
-getting started,
-[x/example/gotypes](https://github.com/golang/example/tree/master/gotypes) is
-a great introduction (and was the inspiration for this guide).
-
-# Summary of new language features and their APIs
-
-While generic Go programming is a large change to the language, at a high level
-it introduces only a few new concepts. Specifically, we can break down our
-discussion into the following three broad categories. In each category, the
-relevant new APIs are listed (some constructors and getters/setters may be
-elided where they are trivial).
-
-**Generic types**. Types and functions may be _generic_, meaning their
-declaration has a non-empty _type parameter list_: as in `type List[T any]
-...` or `func f[T1, T2 any]() { ... }`. Type parameter lists define placeholder
-types (_type parameters_), scoped to the declaration, which may be substituted
-by any type satisfying their corresponding _constraint interface_ to
-_instantiate_ a new type or function.
-
-Generic types may have methods, which declare `receiver type parameters` via
-their receiver type expression: `func (r T[P1, ..., PN]) method(...) (...)
-{...}`.
-
-_New APIs_:
- - The field `ast.TypeSpec.TypeParams` holds the type parameter list syntax for
- type declarations.
- - The field `ast.FuncType.TypeParams` holds the type parameter list syntax for
- function declarations.
- - The type `types.TypeParam` is a `types.Type` representing a type parameter.
- On this type, the `Constraint` and `SetConstraint` methods allow
- getting/setting the constraint, the `Index` method returns the index of the
- type parameter in the type parameter list that declares it, and the `Obj`
- method returns the object declared in the declaration scope for the type
- parameter (a `types.TypeName`).
- - The type `types.TypeParamList` holds a list of type parameters.
- - The method `types.Named.TypeParams` returns the type parameters for a type
- declaration.
- - The method `types.Named.SetTypeParams` sets type parameters on a defined
- type.
- - The function `types.NewSignatureType` creates a new (possibly generic)
- signature type.
- - The method `types.Signature.RecvTypeParams` returns the receiver type
- parameters for a method.
- - The method `types.Signature.TypeParams` returns the type parameters for
- a function.
-
-**Constraint Interfaces**: type parameter constraints are interfaces, expressed
-via an interface type expression. Interfaces that are only used in constraint
-position are permitted new embedded elements composed of tilde expressions
-(`~T`) and unions (`A | B | ~C`). The new builtin interface type `comparable`
-is implemented by types for which `==` and `!=` are valid. As a special case,
-the `interface` keyword may be omitted from constraint expressions if it may be
-implied (in which case we say the interface is _implicit_).
-
-_New APIs_:
- - The constant `token.TILDE` is used to represent tilde expressions as an
- `ast.UnaryExpr`.
- - Union expressions are represented as an `ast.BinaryExpr` using `|`. This
- means that `ast.BinaryExpr` may now be both a type and value expression.
- - The method `types.Interface.IsImplicit` reports whether the `interface`
- keyword was elided from this interface.
- - The method `types.Interface.MarkImplicit` marks an interface as being
- implicit.
- - The method `types.Interface.IsComparable` reports whether every type in an
- interface's type set is comparable.
- - The method `types.Interface.IsMethodSet` reports whether an interface is
- defined entirely by its methods (has no _specific types_).
- - The type `types.Union` is a type that represents an embedded union
- expression in an interface. May only appear as an embedded element in
- interfaces.
- - The type `types.Term` represents a (possibly tilde) term of a union.
-
-**Instantiation**: generic types and functions may be _instantiated_ to create
-non-generic types and functions by providing _type arguments_ (`var x T[int]`).
-Function type arguments may be _inferred_ via function arguments, or via
-type parameter constraints.
-
-_New APIs_:
- - The type `ast.IndexListExpr` holds index expressions with multiple indices,
- as occurs in instantiation expressions with multiple type arguments, or in
- receivers with multiple type parameters.
- - The function `types.Instantiate` instantiates a generic type with type arguments.
- - The type `types.Context` is an opaque instantiation context that may be
- shared to reduce duplicate instances.
- - The field `types.Config.Context` holds a shared `Context` to use for
- instantiation while type-checking.
- - The type `types.TypeList` holds a list of types.
- - The type `types.ArgumentError` holds an error associated with a specific
- argument index. Used to represent instantiation errors.
- - The field `types.Info.Instances` maps instantiated identifiers to information
- about the resulting type instance.
- - The type `types.Instance` holds information about a type or function
- instance.
- - The method `types.Named.TypeArgs` reports the type arguments used to
- instantiate a named type.
-
-# Examples
-
-The following examples demonstrate the new APIs above, and discuss their
-properties. All examples are runnable, contained in subdirectories of the
-directory holding this README.
-
-## Generic types
-
-### Type parameter lists
-
-Suppose we want to understand the generic library below, which defines a generic
-`Pair`, a constraint interface `Constraint`, and a generic function `MakePair`.
-
-```
-package main
-
-type Constraint interface {
- Value() interface{}
-}
-
-type Pair[L, R any] struct {
- left L
- right R
-}
-
-func MakePair[L, R Constraint](l L, r R) Pair[L, R] {
- return Pair[L, R]{l, r}
-}
-```
-
-We can use the new `TypeParams` fields in `ast.TypeSpec` and `ast.FuncType` to
-access the syntax of the type parameter list. From there, we can access type
-parameter types in at least three ways:
- - by looking up type parameter definitions in `types.Info`
- - by calling `TypeParams()` on `types.Named` or `types.Signature`
- - by looking up type parameter objects in the declaration scope. Note that
- there now may be a scope associated with an `ast.TypeSpec` node.
-
-```
-func PrintTypeParams(fset *token.FileSet, file *ast.File) error {
- conf := types.Config{Importer: importer.Default()}
- info := &types.Info{
- Scopes: make(map[ast.Node]*types.Scope),
- Defs: make(map[*ast.Ident]types.Object),
- }
- _, err := conf.Check("hello", fset, []*ast.File{file}, info)
- if err != nil {
- return err
- }
-
- // For convenience, we can use ast.Inspect to find the nodes we want to
- // investigate.
- ast.Inspect(file, func(n ast.Node) bool {
- var name *ast.Ident // the name of the generic object, or nil
- var tparamSyntax *ast.FieldList // the list of type parameter fields
- var tparamTypes *types.TypeParamList // the list of type parameter types
- var scopeNode ast.Node // the node associated with the declaration scope
-
- switch n := n.(type) {
- case *ast.TypeSpec:
- name = n.Name
- tparamSyntax = n.TypeParams
- tparamTypes = info.Defs[name].Type().(*types.Named).TypeParams()
- name = n.Name
- scopeNode = n
- case *ast.FuncDecl:
- name = n.Name
- tparamSyntax = n.Type.TypeParams
- tparamTypes = info.Defs[name].Type().(*types.Signature).TypeParams()
- scopeNode = n.Type
- }
-
- if name == nil {
- return true // not a generic object
- }
-
- // Option 1: find type parameters by looking at their declaring field list.
- if tparamSyntax != nil {
- fmt.Printf("%s has a type parameter field list with %d fields\n", name.Name, tparamSyntax.NumFields())
- for _, field := range tparamSyntax.List {
- for _, name := range field.Names {
- tparam := info.Defs[name]
- fmt.Printf(" field %s defines an object %q\n", name.Name, tparam)
- }
- }
- } else {
- fmt.Printf("%s does not have a type parameter list\n", name.Name)
- }
-
- // Option 2: find type parameters via the TypeParams() method on the
- // generic type.
- fmt.Printf("%s has %d type parameters:\n", name.Name, tparamTypes.Len())
- for i := 0; i < tparamTypes.Len(); i++ {
- tparam := tparamTypes.At(i)
- fmt.Printf(" %s has constraint %s\n", tparam, tparam.Constraint())
- }
-
- // Option 3: find type parameters by looking in the declaration scope.
- scope, ok := info.Scopes[scopeNode]
- if ok {
- fmt.Printf("%s has a scope with %d objects:\n", name.Name, scope.Len())
- for _, name := range scope.Names() {
- fmt.Printf(" %s is a %T\n", name, scope.Lookup(name))
- }
- } else {
- fmt.Printf("%s does not have a scope\n", name.Name)
- }
-
- return true
- })
- return nil
-}
-```
-
-This program produces the following output. Note that not every type spec has
-a scope.
-
-```
-> go run golang.org/x/tools/internal/typeparams/example/findtypeparams
-Constraint does not have a type parameter list
-Constraint has 0 type parameters:
-Constraint does not have a scope
-Pair has a type parameter field list with 2 fields
- field L defines an object "type parameter L any"
- field R defines an object "type parameter R any"
-Pair has 2 type parameters:
- L has constraint any
- R has constraint any
-Pair has a scope with 2 objects:
- L is a *types.TypeName
- R is a *types.TypeName
-MakePair has a type parameter field list with 2 fields
- field L defines an object "type parameter L hello.Constraint"
- field R defines an object "type parameter R hello.Constraint"
-MakePair has 2 type parameters:
- L has constraint hello.Constraint
- R has constraint hello.Constraint
-MakePair has a scope with 4 objects:
- L is a *types.TypeName
- R is a *types.TypeName
- l is a *types.Var
- r is a *types.Var
-```
-
-### Methods on generic types
-
-**TODO**
-
-## Constraint Interfaces
-
-### New interface elements
-
-**TODO**
-
-### Implicit interfaces
-
-**TODO**
-
-### Type sets
-
-**TODO**
-
-## Instantiation
-
-### Finding instantiated types
-
-**TODO**
-
-### Creating new instantiated types
-
-**TODO**
-
-### Using a shared context
-
-**TODO**
-
-# Updating tools while building at older Go versions
-
-In the examples above, we can see how a lot of the new APIs integrate with
-existing usage of `go/ast` or `go/types`. However, most tools still need to
-build at older Go versions, and handling the new language constructs in-line
-will break builds at older Go versions.
-
-For this purpose, the `x/exp/typeparams` package provides functions and types
-that proxy the new APIs (with stub implementations at older Go versions).
-**NOTE**: does not yet exist -- see
-[golang/go#50447](https://go.dev/issues/50447) for more information.
-
-# Further help
-
-If you're working on updating a tool to support generics, and need help, please
-feel free to reach out for help in any of the following ways:
- - Via the [golang-tools](https://groups.google.com/g/golang-tools) mailing list.
- - Directly to me via email (`rfindley@google.com`).
- - For bugs, you can [file an issue](https://github.com/golang/go/issues/new/choose).
diff --git a/internal/typeparams/example/findtypeparams/main.go b/internal/typeparams/example/findtypeparams/main.go
deleted file mode 100644
index b3f10c0..0000000
--- a/internal/typeparams/example/findtypeparams/main.go
+++ /dev/null
@@ -1,155 +0,0 @@
-// Copyright 2021 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.
-
-//go:build go1.18
-// +build go1.18
-
-package main
-
-import (
- "fmt"
- "go/ast"
- "go/importer"
- "go/parser"
- "go/token"
- "go/types"
- "log"
-)
-
-const hello = `
-//!+input
-package main
-
-type Constraint interface {
- Value() interface{}
-}
-
-type Pair[L, R any] struct {
- left L
- right R
-}
-
-func MakePair[L, R Constraint](l L, r R) Pair[L, R] {
- return Pair[L, R]{l, r}
-}
-//!-input
-`
-
-// !+print
-func PrintTypeParams(fset *token.FileSet, file *ast.File) error {
- conf := types.Config{Importer: importer.Default()}
- info := &types.Info{
- Scopes: make(map[ast.Node]*types.Scope),
- Defs: make(map[*ast.Ident]types.Object),
- }
- _, err := conf.Check("hello", fset, []*ast.File{file}, info)
- if err != nil {
- return err
- }
-
- // For convenience, we can use ast.Inspect to find the nodes we want to
- // investigate.
- ast.Inspect(file, func(n ast.Node) bool {
- var name *ast.Ident // the name of the generic object, or nil
- var tparamSyntax *ast.FieldList // the list of type parameter fields
- var tparamTypes *types.TypeParamList // the list of type parameter types
- var scopeNode ast.Node // the node associated with the declaration scope
-
- switch n := n.(type) {
- case *ast.TypeSpec:
- name = n.Name
- tparamSyntax = n.TypeParams
- tparamTypes = info.Defs[name].Type().(*types.Named).TypeParams()
- name = n.Name
- scopeNode = n
- case *ast.FuncDecl:
- name = n.Name
- tparamSyntax = n.Type.TypeParams
- tparamTypes = info.Defs[name].Type().(*types.Signature).TypeParams()
- scopeNode = n.Type
- }
-
- if name == nil {
- return true // not a generic object
- }
-
- // Option 1: find type parameters by looking at their declaring field list.
- if tparamSyntax != nil {
- fmt.Printf("%s has a type parameter field list with %d fields\n", name.Name, tparamSyntax.NumFields())
- for _, field := range tparamSyntax.List {
- for _, name := range field.Names {
- tparam := info.Defs[name]
- fmt.Printf(" field %s defines an object %q\n", name.Name, tparam)
- }
- }
- } else {
- fmt.Printf("%s does not have a type parameter list\n", name.Name)
- }
-
- // Option 2: find type parameters via the TypeParams() method on the
- // generic type.
- fmt.Printf("%s has %d type parameters:\n", name.Name, tparamTypes.Len())
- for i := 0; i < tparamTypes.Len(); i++ {
- tparam := tparamTypes.At(i)
- fmt.Printf(" %s has constraint %s\n", tparam, tparam.Constraint())
- }
-
- // Option 3: find type parameters by looking in the declaration scope.
- scope, ok := info.Scopes[scopeNode]
- if ok {
- fmt.Printf("%s has a scope with %d objects:\n", name.Name, scope.Len())
- for _, name := range scope.Names() {
- fmt.Printf(" %s is a %T\n", name, scope.Lookup(name))
- }
- } else {
- fmt.Printf("%s does not have a scope\n", name.Name)
- }
-
- return true
- })
- return nil
-}
-
-//!-print
-
-/*
-//!+output
-> go run golang.org/x/tools/internal/typeparams/example/findtypeparams
-Constraint does not have a type parameter list
-Constraint has 0 type parameters:
-Constraint does not have a scope
-Pair has a type parameter field list with 2 fields
- field L defines an object "type parameter L any"
- field R defines an object "type parameter R any"
-Pair has 2 type parameters:
- L has constraint any
- R has constraint any
-Pair has a scope with 2 objects:
- L is a *types.TypeName
- R is a *types.TypeName
-MakePair has a type parameter field list with 2 fields
- field L defines an object "type parameter L hello.Constraint"
- field R defines an object "type parameter R hello.Constraint"
-MakePair has 2 type parameters:
- L has constraint hello.Constraint
- R has constraint hello.Constraint
-MakePair has a scope with 4 objects:
- L is a *types.TypeName
- R is a *types.TypeName
- l is a *types.Var
- r is a *types.Var
-//!-output
-*/
-
-func main() {
- // Parse one file.
- fset := token.NewFileSet()
- f, err := parser.ParseFile(fset, "hello.go", hello, 0)
- if err != nil {
- log.Fatal(err) // parse error
- }
- if err := PrintTypeParams(fset, f); err != nil {
- log.Fatal(err) // type error
- }
-}
diff --git a/internal/typeparams/example/generic-go-types.md b/internal/typeparams/example/generic-go-types.md
deleted file mode 100644
index 8d2f6ff..0000000
--- a/internal/typeparams/example/generic-go-types.md
+++ /dev/null
@@ -1,206 +0,0 @@
-<!-- To regenerate the readme, run: -->
-<!-- go run golang.org/x/example/gotypes@latest generic-go-types.md -->
-
-# Updating tools to support type parameters.
-
-This guide is maintained by Rob Findley (`rfindley@google.com`).
-
-**status**: this document is currently a work-in-progress. See
-[golang/go#50447](https://go.dev/issues/50447) for more details.
-
-%toc
-
-# Introduction
-
-With Go 1.18, Go now supports generic programming via type parameters. This
-document is intended to serve as a guide for tool authors that want to update
-their tools to support the new language constructs introduced for generic Go.
-
-This guide assumes some knowledge of the language changes to support generics.
-See the following references for more information:
-
-- The [original proposal](https://go.dev/issue/43651) for type parameters.
-- The [addendum for type sets](https://go.dev/issue/45346).
-- The [latest language specfication](https://tip.golang.org/ref/spec) (still in-progress as of 2021-01-11).
-- The proposals for new APIs in
- [go/token and go/ast](https://go.dev/issue/47781), and in
- [go/types](https://go.dev/issue/47916).
-
-It also assumes existing knowledge of `go/ast` and `go/types`. If you're just
-getting started,
-[x/example/gotypes](https://github.com/golang/example/tree/master/gotypes) is
-a great introduction (and was the inspiration for this guide).
-
-# Summary of new language features and their APIs
-
-While generic Go programming is a large change to the language, at a high level
-it introduces only a few new concepts. Specifically, we can break down our
-discussion into the following three broad categories. In each category, the
-relevant new APIs are listed (some constructors and getters/setters may be
-elided where they are trivial).
-
-**Generic types**. Types and functions may be _generic_, meaning their
-declaration has a non-empty _type parameter list_: as in `type List[T any]
-...` or `func f[T1, T2 any]() { ... }`. Type parameter lists define placeholder
-types (_type parameters_), scoped to the declaration, which may be substituted
-by any type satisfying their corresponding _constraint interface_ to
-_instantiate_ a new type or function.
-
-Generic types may have methods, which declare `receiver type parameters` via
-their receiver type expression: `func (r T[P1, ..., PN]) method(...) (...)
-{...}`.
-
-_New APIs_:
- - The field `ast.TypeSpec.TypeParams` holds the type parameter list syntax for
- type declarations.
- - The field `ast.FuncType.TypeParams` holds the type parameter list syntax for
- function declarations.
- - The type `types.TypeParam` is a `types.Type` representing a type parameter.
- On this type, the `Constraint` and `SetConstraint` methods allow
- getting/setting the constraint, the `Index` method returns the index of the
- type parameter in the type parameter list that declares it, and the `Obj`
- method returns the object declared in the declaration scope for the type
- parameter (a `types.TypeName`).
- - The type `types.TypeParamList` holds a list of type parameters.
- - The method `types.Named.TypeParams` returns the type parameters for a type
- declaration.
- - The method `types.Named.SetTypeParams` sets type parameters on a defined
- type.
- - The function `types.NewSignatureType` creates a new (possibly generic)
- signature type.
- - The method `types.Signature.RecvTypeParams` returns the receiver type
- parameters for a method.
- - The method `types.Signature.TypeParams` returns the type parameters for
- a function.
-
-**Constraint Interfaces**: type parameter constraints are interfaces, expressed
-via an interface type expression. Interfaces that are only used in constraint
-position are permitted new embedded elements composed of tilde expressions
-(`~T`) and unions (`A | B | ~C`). The new builtin interface type `comparable`
-is implemented by types for which `==` and `!=` are valid. As a special case,
-the `interface` keyword may be omitted from constraint expressions if it may be
-implied (in which case we say the interface is _implicit_).
-
-_New APIs_:
- - The constant `token.TILDE` is used to represent tilde expressions as an
- `ast.UnaryExpr`.
- - Union expressions are represented as an `ast.BinaryExpr` using `|`. This
- means that `ast.BinaryExpr` may now be both a type and value expression.
- - The method `types.Interface.IsImplicit` reports whether the `interface`
- keyword was elided from this interface.
- - The method `types.Interface.MarkImplicit` marks an interface as being
- implicit.
- - The method `types.Interface.IsComparable` reports whether every type in an
- interface's type set is comparable.
- - The method `types.Interface.IsMethodSet` reports whether an interface is
- defined entirely by its methods (has no _specific types_).
- - The type `types.Union` is a type that represents an embedded union
- expression in an interface. May only appear as an embedded element in
- interfaces.
- - The type `types.Term` represents a (possibly tilde) term of a union.
-
-**Instantiation**: generic types and functions may be _instantiated_ to create
-non-generic types and functions by providing _type arguments_ (`var x T[int]`).
-Function type arguments may be _inferred_ via function arguments, or via
-type parameter constraints.
-
-_New APIs_:
- - The type `ast.IndexListExpr` holds index expressions with multiple indices,
- as occurs in instantiation expressions with multiple type arguments, or in
- receivers with multiple type parameters.
- - The function `types.Instantiate` instantiates a generic type with type arguments.
- - The type `types.Context` is an opaque instantiation context that may be
- shared to reduce duplicate instances.
- - The field `types.Config.Context` holds a shared `Context` to use for
- instantiation while type-checking.
- - The type `types.TypeList` holds a list of types.
- - The type `types.ArgumentError` holds an error associated with a specific
- argument index. Used to represent instantiation errors.
- - The field `types.Info.Instances` maps instantiated identifiers to information
- about the resulting type instance.
- - The type `types.Instance` holds information about a type or function
- instance.
- - The method `types.Named.TypeArgs` reports the type arguments used to
- instantiate a named type.
-
-# Examples
-
-The following examples demonstrate the new APIs above, and discuss their
-properties. All examples are runnable, contained in subdirectories of the
-directory holding this README.
-
-## Generic types
-
-### Type parameter lists
-
-Suppose we want to understand the generic library below, which defines a generic
-`Pair`, a constraint interface `Constraint`, and a generic function `MakePair`.
-
-%include findtypeparams/main.go input -
-
-We can use the new `TypeParams` fields in `ast.TypeSpec` and `ast.FuncType` to
-access the syntax of the type parameter list. From there, we can access type
-parameter types in at least three ways:
- - by looking up type parameter definitions in `types.Info`
- - by calling `TypeParams()` on `types.Named` or `types.Signature`
- - by looking up type parameter objects in the declaration scope. Note that
- there now may be a scope associated with an `ast.TypeSpec` node.
-
-%include findtypeparams/main.go print -
-
-This program produces the following output. Note that not every type spec has
-a scope.
-
-%include findtypeparams/main.go output -
-
-### Methods on generic types
-
-**TODO**
-
-## Constraint Interfaces
-
-### New interface elements
-
-**TODO**
-
-### Implicit interfaces
-
-**TODO**
-
-### Type sets
-
-**TODO**
-
-## Instantiation
-
-### Finding instantiated types
-
-**TODO**
-
-### Creating new instantiated types
-
-**TODO**
-
-### Using a shared context
-
-**TODO**
-
-# Updating tools while building at older Go versions
-
-In the examples above, we can see how a lot of the new APIs integrate with
-existing usage of `go/ast` or `go/types`. However, most tools still need to
-build at older Go versions, and handling the new language constructs in-line
-will break builds at older Go versions.
-
-For this purpose, the `x/exp/typeparams` package provides functions and types
-that proxy the new APIs (with stub implementations at older Go versions).
-**NOTE**: does not yet exist -- see
-[golang/go#50447](https://go.dev/issues/50447) for more information.
-
-# Further help
-
-If you're working on updating a tool to support generics, and need help, please
-feel free to reach out for help in any of the following ways:
- - Via the [golang-tools](https://groups.google.com/g/golang-tools) mailing list.
- - Directly to me via email (`rfindley@google.com`).
- - For bugs, you can [file an issue](https://github.com/golang/go/issues/new/choose).
