func (w *World) Compile(fset *token.FileSet, text string) (Code, os.Error) {
stmts, err := parser.ParseStmtList(fset, "input", text)
if err == nil {
return w.CompileStmtList(fset, stmts)
}
// Otherwise try as DeclList.
decls, err1 := parser.ParseDeclList(fset, "input", text)
if err1 == nil {
return w.CompileDeclList(fset, decls)
}
// Have to pick an error.
// Parsing as statement list admits more forms,
// its error is more likely to be useful.
return nil, err
}
func main() {
fmt.Println("Welcome to the Go REPL!")
fmt.Println("Enter '?' for a list of commands.")
w := new(World)
w.pkgs = new(vector.StringVector)
w.defs = new(vector.StringVector)
w.code = new(vector.Vector)
buf := bufio.NewReader(os.Stdin)
unstable := false
for {
if unstable {
fmt.Print("! ")
}
fmt.Print(strings.Join(w.pkgs.Data(), " ") + "> ")
read, err := buf.ReadString('\n')
if err != nil {
println()
break
}
line := read[0 : len(read)-1]
if len(line) == 0 {
continue
}
w.exec = ""
switch line[0] {
case '?':
fmt.Println("Commands:")
fmt.Println("\t?\thelp")
fmt.Println("\t+ (pkg)\timport package")
fmt.Println("\t- (pkg)\tremove package")
fmt.Println("\t-[dpc]\tpop last (declaration|package|code)")
fmt.Println("\t~\treset")
fmt.Println("\t: (...)\tadd persistent code")
fmt.Println("\t!\tinspect source")
case '+':
w.pkgs.Push(line[2:])
unstable = true
case '-':
if len(line) > 1 && line[1] != ' ' {
switch line[1] {
case 'd':
if w.defs.Len() > 0 {
w.defs.Pop()
}
case 'p':
if w.pkgs.Len() > 0 {
w.pkgs.Pop()
}
case 'c':
if w.code.Len() > 0 {
w.code.Pop()
}
}
} else {
if len(line) > 2 && w.pkgs.Len() > 0 {
for i, v := range w.pkgs.Data() {
if v == line[2:] {
w.pkgs.Delete(i)
break
}
}
} else {
if w.code.Len() > 0 {
w.code.Pop()
}
}
}
unstable = compile(w).Len() > 0
case '~':
w.pkgs.Resize(0, 0)
w.defs.Resize(0, 0)
w.code.Resize(0, 0)
unstable = false
case '!':
fmt.Println(w.source())
case ':':
tree, err := parser.ParseStmtList("go-repl", line[2:], nil)
if err != nil {
fmt.Println("Parse error:", err)
continue
}
w.code.Push(tree[0])
unstable = compile(w).Len() > 0
default:
var tree interface{}
tree, err := parser.ParseStmtList("go-repl", line[0:], nil)
if err != nil {
tree, err = parser.ParseDeclList("go-repl", line[0:], nil)
if err != nil {
fmt.Println("Parse error:", err)
continue
}
}
changed := false
switch tree.(type) {
case []ast.Stmt:
for _, v := range tree.([]ast.Stmt) {
str := new(bytes.Buffer)
printer.Fprint(str, v)
switch v.(type) {
case *ast.AssignStmt:
w.code.Push(v)
changed = true
default:
w.exec = str.String()
}
}
case []ast.Decl:
for _, v := range tree.([]ast.Decl) {
str := new(bytes.Buffer)
printer.Fprint(str, v)
w.defs.Push(str.String())
}
changed = true
}
if err := compile(w); err.Len() > 0 {
fmt.Println("Compile error:", err)
if changed {
unstable = true
}
} else if out, err := run(); err.Len() > 0 {
fmt.Println("Runtime error:\n", err)
if changed {
unstable = true
}
} else {
fmt.Print(out)
}
}
}
}
func main() {
fmt.Println("Welcome to the Go REPL!")
fmt.Println("Enter '?' for a list of commands.")
w := new(World)
w.pkgs = &[]string{}
w.code = &[]interface{}{}
w.defs = &[]string{}
w.files = token.NewFileSet()
buf := bufio.NewReader(os.Stdin)
unstable := false
for {
if unstable {
fmt.Print("! ")
}
fmt.Print(strings.Join(*w.pkgs, " ") + "> ")
read, err := buf.ReadString('\n')
if err != nil {
println()
break
}
line := read[0 : len(read)-1]
if len(line) == 0 {
continue
}
w.exec = ""
switch line[0] {
case '?':
fmt.Println("Commands:")
fmt.Println("\t?\thelp")
fmt.Println("\t+ (pkg)\timport package")
fmt.Println("\t- (pkg)\tremove package")
fmt.Println("\t-[dpc]\tpop last (declaration|package|code)")
fmt.Println("\t~\treset")
fmt.Println("\t: (...)\tadd persistent code")
fmt.Println("\t!\tinspect source")
case '+':
*w.pkgs = append(*w.pkgs, strings.Trim(line[1:], " "))
unstable = true
case '-':
if len(line) > 1 && line[1] != ' ' {
switch line[1] {
case 'd':
if len(*w.defs) > 0 {
*w.defs = (*w.defs)[:len(*w.defs)-1]
}
case 'p':
if len(*w.pkgs) > 0 {
*w.pkgs = (*w.pkgs)[:len(*w.pkgs)-1]
}
case 'c':
if len(*w.code) > 0 {
*w.code = (*w.code)[:len(*w.code)-1]
}
}
} else {
if len(line) > 2 && len(*w.pkgs) > 0 {
for i, v := range *w.pkgs {
if v == line[2:] {
copy((*w.pkgs)[i:], (*w.pkgs)[i+1:])
*w.pkgs = (*w.pkgs)[:len(*w.pkgs)-1]
break
}
}
} else {
if len(*w.code) > 0 {
*w.code = (*w.code)[:len(*w.code)-1]
}
}
}
unstable = compile(w).Len() > 0
case '~':
*w.pkgs = (*w.pkgs)[:0]
*w.defs = (*w.pkgs)[:0]
*w.code = (*w.code)[:0]
unstable = false
case '!':
fmt.Println(w.source())
case ':':
line = line + ";"
tree, err := parser.ParseStmtList(w.files, "go-repl", strings.Trim(line[1:], " "))
if err != nil {
fmt.Println("Parse error:", err)
continue
}
*w.code = append(*w.code, tree[0])
unstable = compile(w).Len() > 0
default:
line = line + ";"
var tree interface{}
tree, err := parser.ParseStmtList(w.files, "go-repl", line[0:])
if err != nil {
tree, err = parser.ParseDeclList(w.files, "go-repl", line[0:])
if err != nil {
fmt.Println("Parse error:", err)
continue
}
}
changed := false
switch tree.(type) {
case []ast.Stmt:
for _, v := range tree.([]ast.Stmt) {
str := new(bytes.Buffer)
printer.Fprint(str, w.files, v)
switch v.(type) {
case *ast.AssignStmt:
*w.code = append(*w.code, v)
changed = true
default:
w.exec = str.String()
}
}
case []ast.Decl:
for _, v := range tree.([]ast.Decl) {
str := new(bytes.Buffer)
printer.Fprint(str, w.files, v)
*w.defs = append(*w.defs, str.String())
}
changed = true
}
if err := compile(w); err.Len() > 0 {
fmt.Println("Compile error:", err)
if changed {
unstable = true
}
} else if out, err := run(); err.Len() > 0 {
fmt.Println("Runtime error:\n", err)
if changed {
unstable = true
}
} else {
fmt.Print(out)
}
}
}
}