repl wanted

[ghost]

Feature Request

repl needed to write & test script more easily

That is, each time I wanna do something, for example have a look at path.join(), I have to write a simple statement to a file then use xmake lua to run it. That's troublesome. A repl like other script languages have is good-to-use

I tried to impl it by myself but it has trouble with sandbox

[waruqi]

This is a very nice feature, I also wanted to add this feature before. I saw the implementation of luajit.c, It seems not very complicated, I will attempt to implement it in this week if everything goes well.

[ghost]

👍

[waruqi]

I have finished this feature on linux/macosx. (not yet tested it on windows)

You can fetch dev branch and run xmake lua to run interactive commands. for example:

$ xmake lua

> import("core.project.task")
> task.run("hello")
>
> print(path.join("/tmp", "xxx"))
>
> = 1+2+3 / 4
>
> a = 1
> print(a)
>
> for _, v in pairs({1, 2, 3}) do
>> print(v)
>> end

[ghost]

> 1
stdin:1: unexpected symbol near '1'
> a=1
> a
>> 

I think a single val should be printed directly

like python:

>>> 1
1
>>> a=1
>>> a
1

[ghost]

Anyway 👍

[waruqi]

@titansnow I agree with your point, but I don't know how to distinguish them better in lua.

So you need add prefix character '=' to eval expr now.

> = 1 + 3 +5
9
> = 1
1

Or you can help me improve it. interactive.c:168

[ghost]

I'd like to look into it 😃

[ghost]

I found some info on stackoverflow that might be workable

[ghost]

lua 5.3 uses pre-check to know whether a statement could return

  const char *retline = lua_pushfstring(L, "return %s;", line);
  int status = luaL_loadbuffer(L, retline, strlen(retline), "=stdin");
  if (status == LUA_OK) {
    // ...

at lua.c:334 (5.3.4)

if could return then add return otherwise not add return

[waruqi]

@titansnow I tried this way before, but this method can't handle some function calls well. for example:

> import("core.project.task")
> task.run("xxx")  <------ will failed, task not found

These function calls can also be returned, but return import("...") cannot affect the scope of the outside

[ghost]

@waruqi That's too bad 😞 I couldn't figure out why it will be so -- return break scope? Maybe lua is a magic language that makes me 🌀

[waruqi]

@titansnow And it's hard to distinguish whether you want to print the return value. Any function call that has a return value will be printed

for example:

function test()
    -- do some thing

    -- ok
    return true
end

then, we run it using return test()

> test()
true      -- maybe I don't want to see this return value

[ghost]

I think now there are two thing needed to be done:

• in multiline input, I need a cancel way. <C-C>?

• the readline library itself is common in posix system but the headers might be not. On my ubuntu, unless libreadline-dev is installed, there's no header readline/*

  there are two solutions:

  • add require of readline development files
  • do not include the header. Declare them manually:

    diff --git a/core/src/xmake/sandbox/interactive.c b/core/src/xmake/sandbox/interactive.c
    index 339ab9cc..da3c7a8e 100644
    --- a/core/src/xmake/sandbox/interactive.c
    +++ b/core/src/xmake/sandbox/interactive.c
    @@ -41,8 +41,8 @@
      */
     #include "prefix.h"
     #ifndef TB_CONFIG_OS_WINDOWS
    -#   include <readline/readline.h>
    -#   include <readline/history.h>
    +    extern char* readline   (const char*);
    +    extern void  add_history(const char*);
     #endif
    
     /* //////////////////////////////////////////////////////////////////////////////////////

[waruqi]

@titansnow It try loading return expr first now. You can try it.

> 1 + 2
3

> a = 1
> a
1

But you need assign var manually when call import now.

> task = import("core.project.task")
> task.run("hello")

[waruqi]

@titansnow

• in multiline input, I need a cancel way. ?

Use the signal to cancel multiline, this way is too much trouble and can not handle the cross-platform well.

So you can simply input q to cancel multiline input, for example:

> for _, v in ipairs({1, 2}) do
>> print(v)
>> q             <--  cancel multiline and clear previous input
> 1 + 2
3

• the readline library itself is common in posix system but the headers might be not. On my ubuntu, unless libreadline-dev is installed, there's no header readline/*

I fixed it

+    extern char* readline   (const char*);
+    extern void  add_history(const char*);

[ghost]

👍

[ghost]

A very bad message: I tested carefully again, found that although libreadline has installed, xmake couldn't build successfully even declare functions manually, libreadline-dev is required. And libreadline-dev is not one of build-essential package group. So that install scripts must be modified to add this requirement @waruqi

[waruqi]

@titansnow But it passed on ci.Can you give me some build error info? I try to fix it and detect libreadline . If this library not found, I will continue to uses fgets when building.

[ghost]

Travis CI

[ghost]

Three solutions:

• fallback to fgets (reduce user experience)
• install this library via package manager if not found (troublesome)
• bundle readline (impossible because license)

[waruqi]

ok, I will fix it in recent days.

[waruqi]

@titansnow I want to use the following two solutions:

1. Try detect libreadline.a before building, I will use fgets if readline not found. (It done)
2. Modify get.sh to install this library via package manager if not found (Can you help me modify it?)

[ghost]

👌

[waruqi]

@titansnow Thanks! 😸

[ghost]

$ xmake --version
XMake v2.1.4.201705081849, The Make-like Build Utility based on Lua
Copyright (C) 2015-2016 Ruki Wang, tboox.org, xmake.io
Copyright (C) 2005-2015 Mike Pall, luajit.org
$ xmake lua
> os.execv('git',{'--version'})
git version 2.11.0
> os.runv
function: 0xb71601e8
> os.runv('git',{'--version'})
/usr/local/share/xmake/core/base/os.lua:569: runv(git --version) failed(-1)!
stack traceback:
	[C]: in function 'error'
	/usr/local/share/xmake/core/base/os.lua:569: in function 'raise'
	/usr/local/share/xmake/core/sandbox/modules/os.lua:245: in function </usr/local/share/xmake/core/sandbox/modules/os.lua:237>
	[C]: in function 'interactive'
	...ake/core/sandbox/modules/import/core/sandbox/sandbox.lua:51: in function 'interactive'
	/usr/local/share/xmake/plugins/lua/xmake.lua:60: in function </usr/local/share/xmake/plugins/lua/xmake.lua:32>
	[C]: in function 'load'
	/usr/local/share/xmake/core/project/task.lua:423: in function 'run'
	/usr/local/share/xmake/core/main.lua:188: in function </usr/local/share/xmake/core/main.lua:151>
> 

?

[waruqi]

@titansnow I have fixed it.