Re: [ANN] luaprompt 0.6

This is most excellent. The version of Lua that my package manager installs doesn't even include the basic readline support Lua ships with.

I'm having trouble loading it as a module, though, from the lua standalone repl. I installed from rocks, and luap works. But whenever I try to just directly load the module from any version of lua besides 5.2, I get error messages, which are different depending on which lua I'm using.

Thusly:

$ lua5.1 -l prompt -i

lua5.1: error loading module 'prompt' from file '/usr/local/lib/lua/5.1/prompt.so':

dlopen(/usr/local/lib/lua/5.1/prompt.so, 2): Symbol not found: _luaL_loadbufferx

Referenced from: /usr/local/lib/lua/5.1/prompt.so

Expected in: dynamic lookup

stack traceback:

[C]: ?

$ lua5.3 -l prompt -i

lua5.3: error loading module 'prompt' from file '/usr/local/lib/lua/5.3/prompt.so':

dlopen(/usr/local/lib/lua/5.3/prompt.so, 6): Symbol not found: _rl_completion_suppress_append

Referenced from: /usr/local/lib/lua/5.3/prompt.so

Expected in: dynamic lookup

stack traceback:

[C]: in ?

[C]: in function 'require'

[C]: in ?

$ luajit -l prompt -i

luajit: error loading module 'prompt' from file '/usr/local/lib/lua/5.1/prompt.so':

dlopen(/usr/local/lib/lua/5.1/prompt.so, 6): Symbol not found: _luaL_setfuncs

Referenced from: /usr/local/lib/lua/5.1/prompt.so

Expected in: dynamic lookup

stack traceback:

[C]: at 0x010001e14e

[C]: at 0x010001ddbb

[C]: at 0x0100001166

Based on what I'm seeing here, I'd guess that 5.1 (and by extension, jit) aren't supported, but you did explicitly mention that 5.3 is supported.

Under 5.3, it appears not to be loading readline; I manually passed the location to that library when I installed lauprompt (otherwise it just fails). Is this information not cached for runtime use?

On Fri, Jun 12, 2015 at 7:58 AM, Dimitris Papavasiliou <dpapavas@gmail.com> wrote:

luaprompt is both an interactive Lua prompt that can be used instead
of the official interpreter, as well as a module that provides a Lua
command prompt that can be embedded in a host application. As a
standalone interpreter it provides many conveniences that are missing
from the official Lua interpreter. As an embedded prompt, it's meant
for applications that use Lua as a configuration or interface language
and can therefore benefit from an interactive prompt for debugging or
regular use.

luaprompt features:

* Readline-based input with history and completion: In particular all
keywords, global variables and table accesses (with string or
integer keys) can be completed in addition to readline's standard
file completion. Module names are also completed, for modules
installed in the standard directories, and completed modules can
optionally be loaded.

* Persistent command history (retained across sessions).

* Proper value pretty-printing for interactive use: When an _expression_
is entered at the prompt, all returned values are printed
(prepending with an equal sign is not required). Values are printed
in a descriptive way that tries to be as readable as possible. The
formatting tries to mimic Lua code (this is done to minimize
ambiguities and no guarantees are made that it is valid code).
Additionally, each value is stored in a table for future reference.

* Color highlighting of error messages and variable printouts.

This release includes a couple of improvements:

* luaprompt is now available as a module as well as a standalone executable and can be installed via luarocks. Just type

luarocks install luaprompt

to get both the module and the standalone interpreter.

* Some completion-related improvements include the support for __index tables and better filename completion.

* luaprompt now saves the results of each command in a table, which by default is named "_". The use of the feature can most easily be explained by the following excerpt from a luap session:

> io.open "/tmp/hello"
_[1] = file (0x113b110)
> _[1]:read("*a")
_[2] = "Hello World\n"
> _[1]:close()
_[3] = true
> _
_[4] = { file (closed), "Hello World\n", true, }
>

* luaprompt also works with Lua 5.3! Well, no actual change was required to get it to work, I just thought I'd mention it.

For more information, see the README at luaprompt's GitHub page, which you can find at the URL below:

https://github.com/dpapavas/luaprompt

Brigham Toskin