func stripParens(x ast.Expr) ast.Expr {
if px, strip := x.(*ast.ParenExpr); strip {
// parentheses must not be stripped if there are any
// unparenthesized composite literals starting with
// a type name
ast.Inspect(px.X, func(node ast.Node) bool {
switch x := node.(type) {
case *ast.ParenExpr:
// parentheses protect enclosed composite literals
return false
case *ast.CompositeLit:
if isTypeName(x.Type) {
strip = false // do not strip parentheses
}
return false
}
// in all other cases, keep inspecting
return true
})
if strip {
return stripParens(px.X)
}
}
return x
}
// index all the spec definitions for inputs and outputs to element
func (p *compiler) indexParams(d []ast.Decl) {
for i := range d {
switch decl := d[i].(type) {
case *ast.GenDecl:
switch decl.Tok {
case token.PARAMETERS, token.INPUTS:
for j := range decl.Specs {
tmp := decl.Specs[j].(*ast.ValueSpec)
p.params = append(p.params, tmp)
for k := range tmp.Names {
//param := strings.Title(tmp.Names[k].String()) //TODO check input data cannot be lowercase
param := tmp.Names[k].String()
p.paramTypes[param] = p.getTypeString(tmp.Type)
p.paramMap[param] = "p." + param
}
}
case token.OUTPUTS, token.DATA:
for j := range decl.Specs {
tmp := decl.Specs[j].(*ast.ValueSpec)
p.results = append(p.results, tmp)
for k := range tmp.Names {
if string(tmp.Names[k].String()[0]) == strings.ToUpper(string(tmp.Names[k].String()[0])) {
result := tmp.Names[k].String()
p.paramTypes[result] = p.getTypeString(tmp.Type)
p.resultMap[result] = "r." + result //assign to resultblock, later staged
} else { //lowercase, assign to resultblock
result := tmp.Names[k].String()
p.paramTypes[result] = p.getTypeString(tmp.Type)
p.resultMap[result] = "r." + result
}
}
}
}
case *ast.AnthaDecl:
var ref ast.AnthaDecl
ref = *decl
tok := ref.Tok
ast.Inspect(ref.Body, func(n ast.Node) bool {
switch n.(type) {
case *ast.Ident:
if _, is := p.resultMap[n.(*ast.Ident).Name]; is {
varName := n.(*ast.Ident).Name
if _, ok := p.reuseMap[tok]; !ok {
p.reuseMap[tok] = make(map[string]bool)
}
p.reuseMap[tok][varName] = true
}
}
return true
})
default:
continue
}
}
}
func TestObjects(t *testing.T) {
const src = `
package p
import fmt "fmt"
const pi = 3.14
type T struct{}
var x int
func f() { L: }
`
f, err := ParseFile(fset, "", src, 0)
if err != nil {
t.Fatal(err)
}
objects := map[string]ast.ObjKind{
"p": ast.Bad, // not in a scope
"fmt": ast.Bad, // not resolved yet
"pi": ast.Con,
"T": ast.Typ,
"x": ast.Var,
"int": ast.Bad, // not resolved yet
"f": ast.Fun,
"L": ast.Lbl,
}
ast.Inspect(f, func(n ast.Node) bool {
if ident, ok := n.(*ast.Ident); ok {
obj := ident.Obj
if obj == nil {
if objects[ident.Name] != ast.Bad {
t.Errorf("no object for %s", ident.Name)
}
return true
}
if obj.Name != ident.Name {
t.Errorf("names don't match: obj.Name = %s, ident.Name = %s", obj.Name, ident.Name)
}
kind := objects[ident.Name]
if obj.Kind != kind {
t.Errorf("%s: obj.Kind = %s; want %s", ident.Name, obj.Kind, kind)
}
}
return true
})
}
// Replace bare antha function names with go qualified names
func (p *compiler) sugarForIntrinsics(root ast.Node) {
ast.Inspect(root, func(n ast.Node) bool {
switch node := n.(type) {
case nil:
return false
case *ast.Ident:
// sugar the name if it is a known param
if sugar, ok := p.intrinsicMap[node.Name]; ok {
node.Name = sugar
}
// test if the left hand side of an assignment is to a results variable
// if so, sugar it by replacing the = with a channel operation
default:
}
return true
})
}
// Replace bare antha identifiers with go qualified names
func (p *compiler) sugarForParams(body *ast.BlockStmt) {
list := body.List
for i := range list {
ast.Inspect(list[i], func(n ast.Node) bool {
switch node := n.(type) {
case nil:
return false
case *ast.Ident:
// sugar the name if it is a known param
if sugar, ok := p.paramMap[node.Name]; ok {
node.Name = sugar
} else if sugar, ok := p.resultMap[node.Name]; ok {
node.Name = sugar
}
// test if the left hand side of an assignment is to a results variable
// if so, sugar it by replacing the = with a channel operation
case *ast.AssignStmt:
// test if a result is being assigned to.
fix_assign := false
for j := range node.Lhs {
if ident, ok := node.Lhs[j].(*ast.Ident); ok {
isUpper := string(ident.Name[0]) == strings.ToUpper(string(ident.Name[0]))
if sugar, fixme := p.resultMap[ident.Name]; fixme && isUpper {
//fix_assign = true
ident.Name = sugar
}
}
}
//TODO: generate multiple stmts if needed
if fix_assign {
if len(node.Rhs) > 1 {
// currently undefined so panic
panic("too many right hand exprs")
}
list[i] = &ast.SendStmt{node.Lhs[0], node.TokPos, p.wrapParamExpr(node.Rhs[0])}
}
default:
}
return true
})
}
}
// This example demonstrates how to inspect the AST of a Go/Antha program.
func ExampleInspect() {
// src is the input for which we want to inspect the AST.
src := `
package p
const c = 1.0
var X = f(3.14)*2 + c
`
// Create the AST by parsing src.
fset := token.NewFileSet() // positions are relative to fset
f, err := parser.ParseFile(fset, "src.go", src, 0)
if err != nil {
panic(err)
}
// Inspect the AST and print all identifiers and literals.
ast.Inspect(f, func(n ast.Node) bool {
var s string
switch x := n.(type) {
case *ast.BasicLit:
s = x.Value
case *ast.Ident:
s = x.Name
}
if s != "" {
fmt.Printf("%s:\t%s\n", fset.Position(n.Pos()), s)
}
return true
})
// output:
// src.go:2:9: p
// src.go:3:7: c
// src.go:3:11: 1.0
// src.go:4:5: X
// src.go:4:9: f
// src.go:4:11: 3.14
// src.go:4:17: 2
// src.go:4:21: c
}
// playExample synthesizes a new *ast.File based on the provided
// file with the provided function body as the body of main.
func playExample(file *ast.File, body *ast.BlockStmt) *ast.File {
if !strings.HasSuffix(file.Name.Name, "_test") {
// We don't support examples that are part of the
// greater package (yet).
return nil
}
// Find top-level declarations in the file.
topDecls := make(map[*ast.Object]bool)
for _, decl := range file.Decls {
switch d := decl.(type) {
case *ast.FuncDecl:
topDecls[d.Name.Obj] = true
case *ast.GenDecl:
for _, spec := range d.Specs {
switch s := spec.(type) {
case *ast.TypeSpec:
topDecls[s.Name.Obj] = true
case *ast.ValueSpec:
for _, id := range s.Names {
topDecls[id.Obj] = true
}
}
}
}
}
// Find unresolved identifiers and uses of top-level declarations.
unresolved := make(map[string]bool)
usesTopDecl := false
var inspectFunc func(ast.Node) bool
inspectFunc = func(n ast.Node) bool {
// For selector expressions, only inspect the left hand side.
// (For an expression like fmt.Println, only add "fmt" to the
// set of unresolved names, not "Println".)
if e, ok := n.(*ast.SelectorExpr); ok {
ast.Inspect(e.X, inspectFunc)
return false
}
// For key value expressions, only inspect the value
// as the key should be resolved by the type of the
// composite literal.
if e, ok := n.(*ast.KeyValueExpr); ok {
ast.Inspect(e.Value, inspectFunc)
return false
}
if id, ok := n.(*ast.Ident); ok {
if id.Obj == nil {
unresolved[id.Name] = true
} else if topDecls[id.Obj] {
usesTopDecl = true
}
}
return true
}
ast.Inspect(body, inspectFunc)
if usesTopDecl {
// We don't support examples that are not self-contained (yet).
return nil
}
// Remove predeclared identifiers from unresolved list.
for n := range unresolved {
if predeclaredTypes[n] || predeclaredConstants[n] || predeclaredFuncs[n] {
delete(unresolved, n)
}
}
// Use unresolved identifiers to determine the imports used by this
// example. The heuristic assumes package names match base import
// paths for imports w/o renames (should be good enough most of the time).
namedImports := make(map[string]string) // [name]path
var blankImports []ast.Spec // _ imports
for _, s := range file.Imports {
p, err := strconv.Unquote(s.Path.Value)
if err != nil {
continue
}
n := path.Base(p)
if s.Name != nil {
n = s.Name.Name
switch n {
case "_":
blankImports = append(blankImports, s)
continue
case ".":
// We can't resolve dot imports (yet).
return nil
}
}
if unresolved[n] {
namedImports[n] = p
delete(unresolved, n)
}
}
// If there are other unresolved identifiers, give up because this
// synthesized file is not going to build.
if len(unresolved) > 0 {
return nil
}
// Include documentation belonging to blank imports.
var comments []*ast.CommentGroup
for _, s := range blankImports {
if c := s.(*ast.ImportSpec).Doc; c != nil {
comments = append(comments, c)
}
}
// Include comments that are inside the function body.
for _, c := range file.Comments {
if body.Pos() <= c.Pos() && c.End() <= body.End() {
comments = append(comments, c)
}
}
// Strip "Output:" comment and adjust body end position.
body, comments = stripOutputComment(body, comments)
// Synthesize import declaration.
importDecl := &ast.GenDecl{
Tok: token.IMPORT,
Lparen: 1, // Need non-zero Lparen and Rparen so that printer
Rparen: 1, // treats this as a factored import.
}
for n, p := range namedImports {
s := &ast.ImportSpec{Path: &ast.BasicLit{Value: strconv.Quote(p)}}
if path.Base(p) != n {
s.Name = ast.NewIdent(n)
}
importDecl.Specs = append(importDecl.Specs, s)
}
importDecl.Specs = append(importDecl.Specs, blankImports...)
// Synthesize main function.
funcDecl := &ast.FuncDecl{
Name: ast.NewIdent("main"),
Type: &ast.FuncType{Params: &ast.FieldList{}}, // FuncType.Params must be non-nil
Body: body,
}
// Synthesize file.
return &ast.File{
Name: ast.NewIdent("main"),
Decls: []ast.Decl{importDecl, funcDecl},
Comments: comments,
}
}