8000 repl: line editing with history and completion · go-python/gpython@5775015 · GitHub
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repl: line editing with history and completion
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‎notes.txt

Lines changed: 43 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -8,6 +8,49 @@ IDEA replace all .(cast) with CheckExactString or whatever python calls it...
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Then can use CheckString later...
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Instead of using TypeCall etc, just implement all the __methods__ for
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Type. Then there is one and only one way of calling the __methods__.
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How subclass a builtin type? Methods etc should work fine, but want
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CheckString to return the "string" out of the superclass.
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Things to do before release
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===========================
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* Line numbers
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* compile single
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* interactive interpreter
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* Subclass builtins
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* pygen
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FIXME recursive types for __repr__ in list, dict, tuple
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>>> L=[0]
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>>> L[0]=L
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>>> L
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[[...]]
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interactive interpreter
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calls compile(..."single) until doesn't get "SyntaxError: unexpected EOF while parsing" ?
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see pythonrun.c
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PyRun_InteractiveOneObject(FILE *fp, PyObject *filename, PyCompilerFlags *flags)
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...
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mod = PyParser_ASTFromFileObject(fp, filename, enc,
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Py_single_input, ps1, ps2,
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flags, &errcode, arena);
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Py_XDECREF(v);
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Py_XDECREF(w);
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Py_XDECREF(oenc);
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if (mod == NULL) {
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PyArena_Free(arena);
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if (errcode == E_EOF) {
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PyErr_Clear();
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return E_EOF;
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}
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PyErr_Print();
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return -1;
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}
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Limitations & Missing parts
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===========================
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* string keys only in dictionaries

‎repl/repl.go

Lines changed: 129 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -2,36 +2,151 @@
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package repl
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import (
5-
"bufio"
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"fmt"
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"io"
8-
"log"
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"os"
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"os/user"
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"path/filepath"
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"sort"
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"strings"
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"github.com/ncw/gpython/compile"
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"github.com/ncw/gpython/py"
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"github.com/ncw/gpython/vm"
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"github.com/peterh/liner"
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)
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const HistoryFileName = ".gpyhistory"
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// homeDirectory finds the home directory or returns ""
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func homeDirectory() string {
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usr, err := user.Current()
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if err == nil {
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return usr.HomeDir
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}
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// Fall back to reading $HOME - work around user.Current() not
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// working for cross compiled binaries on OSX.
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// https://github.com/golang/go/issues/6376
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return os.Getenv("HOME")
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}
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// Holds state for readline services
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type readline struct {
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*liner.State
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historyFile string
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module *py.Module
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}
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// newReadline creates a new instance of readline
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func newReadline(module *py.Module) *readline {
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rl := &readline{
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State: liner.NewLiner(),
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module: module,
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}
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home := homeDirectory()
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if home != "" {
F438 48+
rl.historyFile = filepath.Join(home, HistoryFileName)
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}
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rl.SetTabCompletionStyle(liner.TabPrints)
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rl.SetWordCompleter(rl.Completer)
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return rl
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}
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// readHistory reads the history into the term
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func (rl *readline) ReadHistory() error {
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f, err := os.Open(rl.historyFile)
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if err != nil {
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return err
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}
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defer f.Close()
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_, err = rl.State.ReadHistory(f)
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if err != nil {
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return err
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}
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return nil
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}
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// writeHistory writes the history from the term
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func (rl *readline) WriteHistory() error {
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f, err := os.OpenFile(rl.historyFile, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0666)
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if err != nil {
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return err
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}
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defer f.Close()
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_, err = rl.State.WriteHistory(f)
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if err != nil {
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return err
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}
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return nil
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}
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// Close the readline and write history
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func (rl *readline) Close() error {
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err := rl.State.Close()
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if err != nil {
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return err
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}
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if rl.historyFile != "" {
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err := rl.WriteHistory()
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if err != nil {
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return err
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}
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}
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return nil
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}
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// WordCompleter takes the currently edited line with the cursor
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// position and returns the completion candidates for the partial word
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// to be completed. If the line is "Hello, wo!!!" and the cursor is
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// before the first '!', ("Hello, wo!!!", 9) is passed to the
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// completer which may returns ("Hello, ", {"world", "Word"}, "!!!")
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// to have "Hello, world!!!".
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func (rl *readline) Completer(line string, pos int) (head string, completions []string, tail string) {
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head = line[:pos]
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tail = line[pos:]
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lastSpace := strings.LastIndex(head, " ")
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head, partial := line[:lastSpace+1], line[lastSpace+1:]
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// log.Printf("head = %q, partial = %q, tail = %q", head, partial, tail)
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found := make(map[string]struct{})
111+
match := func(d py.StringDict) {
112+
for k := range d {
113+
if strings.HasPrefix(k, partial) {
114+
if _, ok := found[k]; !ok {
115+
completions = append(completions, k)
116+
found[k] = struct{}{}
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}
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}
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}
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}
121+
match(rl.module.Globals)
122+
match(py.Builtins.Globals)
123+
sort.Strings(completions)
124+
return head, completions, tail
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}
126+
16127
func Run() {
17-
fmt.Printf("Gpython 3.4.0\n")
18-
bio := bufio.NewReader(os.Stdin)
19128
module := py.NewModule("__main__", "", nil, nil)
129+
rl := newReadline(module)
130+
defer rl.Close()
131+
err := rl.ReadHistory()
132+
if err != nil {
133+
fmt.Printf("Failed to open history: %v\n", err)
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}
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136+
fmt.Printf("Gpython 3.4.0\n")
20137
prog := "<stdin>"
21138
module.Globals["__file__"] = py.String(prog)
22139
for {
23-
fmt.Printf(">>> ")
24-
line, hasMoreInLine, err := bio.ReadLine()
25-
if err == io.EOF {
26-
break
27-
}
140+
line, err := rl.Prompt(">>> ")
28141
if err != nil {
29-
log.Printf("Error: %v", err)
30-
break
31-
}
32-
if hasMoreInLine {
33-
log.Printf("Line truncated")
142+
if err == io.EOF {
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fmt.Printf("\n")
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break
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}
146+
fmt.Printf("Problem reading line: %v\n", err)
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continue
34148
}
149+
rl.AppendHistory(line)
35150
// FIXME need +"\n" because "single" is broken
36151
obj, err := compile.Compile(string(line)+"\n", prog, "single", 0, true)
37152
if err != nil {

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