taking-the-l/lib/fennel

#!/usr/bin/env lua

local fennel_dir = arg[0]:match("(.-)[^\\/]+$")
package.path = fennel_dir .. "?.lua;" .. package.path
local fennel = require('fennel')

local help = [[
Usage: fennel [FLAG] [FILE]

  --repl          :  Launch an interactive repl session
  --compile FILES :  Compile files and write their Lua to stdout
  --help          :  Display this text

  When not given a flag, runs the file given as the first argument.]]

local options = {
    sourcemap = true,
}

local function dosafe(filename, opts, arg1)
    local ok, val = xpcall(function()
        return fennel.dofile(filename, opts, arg1)
    end, fennel.traceback)
    if not ok then
        print(val)
        os.exit(1)
    end
    return val
end

local compileOptHandlers = {
    ['--indent'] = function ()
        options.indent = table.remove(arg, 3)
        if options.indent == "false" then options.indent = false end
        table.remove(arg, 2)
    end,
    ['--sourcemap'] = function ()
        options.sourcemap = table.remove(arg, 3)
        if options.sourcemap == "false" then options.sourcemap = false end
        table.remove(arg, 2)
    end,
    ['--correlate'] = function ()
        options.correlate = true
        table.remove(arg, 2)
    end,
}

if arg[1] == "--repl" or #arg == 0 then
    local ppok, pp = pcall(fennel.dofile, fennel_dir .. "fennelview.fnl", options)
    if ppok then
        options.pp = pp
    end
    local initFilename = (os.getenv("HOME") or "") .. "/.fennelrc"
    local init = io.open(initFilename, "rb")
    if init then
        init:close()
        -- pass in options so fennerlrc can make changes to it
        dosafe(initFilename, options, options)
    end
    print("Welcome to fennel!")
    fennel.repl(options)
elseif arg[1] == "--compile" then
    -- Handle options
    while compileOptHandlers[arg[2]] do
        compileOptHandlers[arg[2]]()
    end
    for i = 2, #arg do
        local f = assert(io.open(arg[i], "rb"))
        options.filename=arg[i]
        local ok, val = xpcall(function()
            return fennel.compileString(f:read("*all"), options)
        end, fennel.traceback)
        print(val)
        if not ok then os.exit(1) end
        f:close()
    end
elseif #arg >= 1 and arg[1] ~= "--help" then
    local filename = table.remove(arg, 1) -- let the script have remaining args
    dosafe(filename)
else
    print(help)
end