cmdline.md

• CommandLine Usage
  • running source
  • print AST
  • print Lua code
  • enter REPL env
  • project config

CommandLine Usage

get help with option '-h' or leave it blank

$ moocscript
Usage: [OPTIONS] SOURCE.[lua|mooc]
        '' load SOURCE and run
        -h print help
        -a print AST
        -s print Lua code
        -i enter REPL
        -p generate Lua code with project config
        -v version

running source

you can directly running .lua or .mooc

$ moocscript FILE.lua

or

$ moocscript FILE.mooc

and only support .lua or .mooc files

print AST

using option '-a' to get AST table

$ moocscript -a FILE.mooc

for example, create 'do.mooc' with content

do {
        print("Hello, world!")
}

and run as

$ moocscript -a do.mooc
{
  [1] = {
    ["body"] = {
      [1] = {
        [1] = {
          [1] = {
            ["pos"] = 14,
            ["etype"] = "var",
            ["value"] = "print"
          },
          [2] = {
            [1] = {
              ["pos"] = 20,
              ["etype"] = "const",
              ["value"] = "Hello, world!"
            },
            ["etype"] = "("
          },
          ["etype"] = "exp"
        },
        ["stype"] = "("
      }
    },
    ["stype"] = "do"
  }
}

the output can use as a Lua table directly, there is little different between using from inside, for 'etype' string value, ignore ", ', [[, but using ", that is trivial.

the AST shows details about source file

• 'stype' means statement
• 'etype' means expression
• 'pos' means position, offsets from file beginning
• 'body' for statements holds code block, another statments

and here shows part of it.

print Lua code

for example

$ moocscript -s do.mooc
do
        print("Hello, world !")
end

enter REPL env

you can play with it without an editor:

$ ./bin/moocscript -i
moocscript v0.7.20221006, Lua 5.4
> export * -- default global variable
> class Person {
	name = ''
	fn init(name) {
		self.name = name
	}
	fn intro() {
		return "My name is \(self.name)"
	}
}
> peter = Person("Peter")
> print(peter:intro())
My name is peter

project config

you can output Lua source before running, and the output Lua source will not require any MoonCake component.

project buildling requires luafilesystem (lfs)

you can take a look at 'examples/proj/proj_config.mooc' for example.

return {
    {
        name = "proj first",
        proj_export = "exp_export.mooc",
        proj_dir = "examples",
        proj_out = "out",
        fn_filter = { in_path in
            return true
        },
        fn_after = { out_path, lua_source_string in
            return lua_source_string
        }
    },
    {
        name = "proj second",
        proj_export = "exp_export.mooc",
        proj_dir = "examples",
        proj_out = "out"
    },
}

here shows two project config, or two source directory.

• name entry no meanings for MoonCake
• proj_export for export variable declared forward as global variable
• proj_dir is the input directory
• proj_out is the output directory
• fn_filter will filter in path, return false if you do not want to copy or output Lua source
• fn_after will be called after Lua code generated and before write to out path, you can modify output content here

in project mode, MoonCake will travel proj_dir recursively, translate all .mooc file to .lua into proj_out directory, the travel order will not as it running, a required calling order, maybe it will meet many global variable before declared, and it will cause error.

you should declare these global names in 'proj_export' file before.

running 'examples/proj/proj_config.mooc' for example

$ moocscript -p examples/proj/proj_config.mooc
---
proj: [proj first]
from: [examples]
 to : [out]
 on : filter
 on : after
 DIR 'out/error'
Error: defer only support function scope
File: examples/error/compile_error.mooc
Line: 1 (Pos: 0)
Source: defer {
        ^
 ERR 'out/error/compile_error.mooc':

the output is quite straight forward, 'ERR' means compile error, before it shows error details.

any error will stop project building.