Initial commit

1 files changed, 444 insertions, 0 deletions

diff --git a/src/glum.lua b/src/glum.lua
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index 0000000..ff05953
--- /dev/null
+++ b/src/glum.lua
@@ -0,0 +1,444 @@
+--[[
+This moudle allows you to minify gLua code
+    Use:
+        local x = require("glum.lua")
+        local str ="
+        --Here is some code to be minified!\n
+        for a=1,10,2 do\n
+            print(a)\n
+        end
+        "
+        print(x.minify(str))
+    Dependencies:
+        lua-parser
+]]
+local parser = dofile("../src/parser.lua")
+local lpeg = require("lpeg")
+lpeg.locale(lpeg)
+
+local glum = {}
+
+--- Creates a deep copy of a table.
+-- Creates a deep copy, will even copy metamethods.
+-- @tab orig the original table to copy
+-- @return a copy of the table
+local function deepcopy(orig) end   --Creates a deep copy of a table
+
+local function getnextvarname(latname) end --generates the next valid variable name from the last valid variable name.
+
+local function printtable(tbl) end --A debugging function, a replacement for glua PrintTable
+
+local function stringfor(ast,tbl) end --Returns the string for the given abstract syntax tree, within the scope of tbl
+
+local function removespaces(string) end --Removes extra spaces and semicolons in string
+
+
+--Creates a deep copy of a table
+local function deepcopy(orig)
+    local orig_type = type(orig)
+    local copy
+    if orig_type == "table" then
+        copy = {}
+        for orig_key, orig_value in next, orig, nil do
+            copy[deepcopy(orig_key)] = deepcopy(orig_value)
+        end
+        setmetatable(copy, deepcopy(getmetatable(orig)))
+    else -- number, string, boolean, etc
+        copy = orig
+    end
+    return copy
+end
+
+--A list of reserved words that cannot be used as variable names
+local nonames = {"if","for","end","do","local","then","else","elseif","return","goto","function","nil","false","true","repeat","return","break","and","or","not","in","repeat","until","while","continue"}
+local reservednames = {}
+for k,v in ipairs(nonames) do
+    reservednames[v] = true
+end
+
+--A function that generates the next valid variable name from the last valid variable name.
+local varchars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXY"
+local function getnextvarname(lname)
+    local place = string.find(lname,"[" .. varchars .. "]")
+    local length = string.len(lname)
+    if place == nil then
+        return string.rep("a", length + 1)
+    else
+        local lbyte = string.byte(lname,place)
+        local newchar = string.char(lbyte + (lbyte < 122 and 1 or -57))
+        local after = string.sub(lname, place + 1, length)
+        local before = string.rep("a", place-1)
+        local output = before .. newchar .. after
+        while reservednames[output] or _G[output] do
+            output = getnextvarname(output)
+        end
+        return output
+    end
+end
+
+--A debugging function, a replacement for glua PrintTable
+local function printtable(tbl, tabset)
+    tabset = tabset or 0
+    for k,v in pairs(tbl) do
+        for i = 0,tabset do io.write("\t") end
+        io.write(k .. ":")
+        if type(v) == "table" then
+            io.write("\n")
+            printtable(v, tabset + 1)
+        else
+            io.write(tostring(v) .. "\n")
+        end
+    end
+end
+
+--Abandon all hope, ye who enter here
+--Refer to the comments at the top of parser.lua for what each function should do.
+--If willox ever decides to add new language features, they need to be added to BOTH parser.lua and here.
+local syntax = {
+    ["Call"] = function(ast,tbl)
+        local exprname = stringfor(ast[1],tbl)
+        local argnames = {}
+        local cursor = 2
+        while ast[cursor] ~= nil do
+            argnames[cursor-1] = stringfor(ast[cursor],tbl)
+            cursor = cursor + 1
+        end
+        local argstring = table.concat(argnames,",")
+        local ostring = table.concat({exprname,"(",argstring,")"})
+        return ostring
+    end,
+    ["Invoke"] = function(ast,tbl)
+        local func = stringfor(ast[1],tbl)
+        local invargs = {}
+        for k = 3,#ast do
+            invargs[#invargs + 1] = stringfor(ast[k],tbl)
+        end
+        local output = func
+        local inv
+        --A short hand if it's a simple thing
+        if ast[2].tag == "String" and #ast[2][1] < (#func + 2) then
+            inv = ast[2][1]
+            output = output .. ":" .. inv .. "("
+        else
+            inv = stringfor(ast[2],tbl)
+            output = output .. "[" .. inv .. "](" .. func .. ","
+        end
+        output = output .. table.concat(invargs,",")
+        output = output .. ")"
+        return output
+    end,
+    ["String"] = function(ast,tbl)
+        if tbl.strings[ast[1]] == nil then
+            local nextvar = getnextvarname(tbl.lname)
+            tbl.lname = nextvar
+            tbl.strings[ast[1]] = nextvar
+            return nextvar
+        end
+        return tbl.strings[ast[1]]
+    end,
+    ["Id"] = function(ast,tbl)
+        if tbl.ids[ast[1]] == nil then
+            return ast[1]
+        end
+        return tbl.ids[ast[1]]
+    end,
+    ["Index"] = function(ast,tbl)
+        local globalvar = stringfor(ast[1],tbl)
+        if ast[2].tag == "String" then
+             return table.concat({globalvar, ".", ast[2][1]})
+        end
+        return table.concat({globalvar, "[", stringfor(ast[2],tbl), "]"})
+    end,
+    ["Paren"] = function(ast,tbl)
+        return table.concat({"(" .. stringfor(ast[1],tbl) .. ")"})
+    end,
+    ["Dots"] = function(ast,tbl)
+        return "..."
+    end,
+    ["Forin"] = function(ast,tbl)
+        local nadd = deepcopy(tbl)
+        local nl = stringfor(ast[1],nadd)
+        local el = stringfor(ast[2],nadd)
+        local code = stringfor(ast[3],nadd)
+        local output = table.concat({" for ", nl, " in ", el, " do ", code, " end "})
+        return output
+    end,
+    ["NameList"] = function(ast,tbl)
+        local outputtbl = {}
+        for k = 1,#ast do
+            if ast[k].tag ~= "Id" then
+                outputtbl[#outputtbl + 1] = stringfor(ast[k])
+            else
+                if tbl.ids[ast[k][1]] ~= nil then
+                    outputtbl[#outputtbl + 1] = tbl.ids[ast[k][1]]
+                else
+                    local newvar = getnextvarname(tbl.lname)
+                    tbl.lname = newvar
+                    tbl.ids[ast[k][1]] = newvar
+                    outputtbl[#outputtbl + 1] = newvar
+                end
+            end
+        end
+        local output = table.concat(outputtbl, ",")
+        return output
+    end,
+    ["ExpList"] = function(ast,tbl)
+        local exprs = {}
+        for k = 1,#ast do
+            exprs[#exprs + 1] = stringfor(ast[k],tbl)
+        end
+        return table.concat(exprs,",")
+    end,
+    ["Nil"] = function(ast,tbl)
+        return "nil"
+    end,
+    ["True"] = function(ast,tbl)
+        return "true"
+    end,
+    ["False"] = function(ast,tbl)
+        return "false"
+    end,
+    ["Return"] = function(ast,tbl)
+        local retargs = {}
+        for k,v in ipairs(ast) do
+            retargs[k] = stringfor(v,tbl)
+        end
+        return " return " .. table.concat(retargs,",")
+    end,
+    ["If"] = function(ast,tbl)
+
+        local expr1 = stringfor(ast[1],tbl)
+        local block1 = stringfor(ast[2],tbl)
+        local codeblocks = {}
+        codeblocks[#codeblocks + 1] = table.concat({" if ",expr1," then ",block1})
+
+        for k = 3,#ast-1,2 do
+            local expr = stringfor(ast[k],tbl)
+            local block = stringfor(ast[k + 1],tbl)
+            codeblocks[#codeblocks + 1] = table.concat({" elseif " , expr , " then " , block})
+        end
+
+        if #ast % 2 == 1 then
+            local block = stringfor(ast[#ast],tbl)
+            codeblocks[#codeblocks + 1] = " else " .. block
+        end
+        codeblocks[#codeblocks + 1] = " end "
+        return table.concat(codeblocks)
+    end,
+    ["Fornum"] = function(ast,tbl)
+        local var
+        if ast[1].tag == "Id" then
+            if tbl.ids[ast[1][1]] ~= nil then
+                var = tbl.ids[ast[1][1]]
+            else
+                local newvar = getnextvarname(tbl.lname)
+                tbl.lname = newvar
+                tbl.ids[ast[1][1]] = newvar
+                var = newvar
+            end
+        else
+            var = stringfor(ast[1],tbl)
+        end
+        local start = stringfor(ast[2],tbl)
+        local endnum = stringfor(ast[3],tbl)
+        local incrementer = 1
+        local code = ""
+        if ast[4].tag ~= "Block" then -- incrementer
+            incrementer = stringfor(ast[4],tbl)
+            code = stringfor(ast[5],tbl)
+        else
+            code = stringfor(ast[4],tbl)
+        end
+        local incstr = incrementer ~= 1 and ("," .. incrementer) or ""
+        tbl[var] = nil
+        return table.concat({" for ",var,"=",start,",",endnum,incstr," do ",code," end "})
+    end,
+    ["Op"] = function(ast,tbl)
+        local binop = {
+            ["or"] = " or ",    ["and"] = " and ",
+            ["ne"] = "~=",      ["eq"] = "==",
+            ["le"] = "<=",      ["ge"] = ">=",
+            ["lt"] = "<",       ["gt"] = ">",
+            ["bor"] = "|",      ["bxor"] = "~",
+            ["band"] = "&",     ["shl"] = "<<",
+            ["shr"] = ">>",     ["concat"] = "..",
+            ["add"] = "+",      ["sub"] = "-",
+            ["mul"] = "*",      ["div"] = "/",
+            ["mod"] = "%",      ["pow"] = "^",
+        }
+        local uniop = {
+            ["len"] = "#",      ["not"] = "not",
+            ["unm"] = "-",      ["bnot"] = "~",
+        }
+        local opname = ast[1]
+        if uniop[opname] ~= nil then
+            local rhs = stringfor(ast[2],tbl)
+            return optbl[opname] .. rhs
+        end
+        local lhs = stringfor(ast[2],tbl)
+        local rhs = stringfor(ast[3],tbl)
+        local output = table.concat(lhs,binop[opname],rhs)
+        return output
+    end,
+    ["Pair"] = function(ast,tbl)
+        local lhs = stringfor(ast[1],tbl)
+        local rhs = stringfor(ast[2],tbl)
+        return table.concat({"[",lhs,"]=",rhs})
+    end,
+    ["Table"] = function(ast,tbl)
+        local fields = {}
+        for k = 1, #ast do
+            fields[#fields + 1] = stringfor(ast[k],tbl)
+        end
+        local fieldstr = table.concat(fields,",")
+        return table.concat({"{",fieldstr,"}"})
+    end,
+    ["Number"] = function(ast,tbl)
+        return ast[1]
+    end,
+    ["Local"] = function(ast,tbl)
+        local tblcpy = tbl
+        local lhs,rhs = stringfor(ast[1],tblcpy),nil
+        if ast[2].tag ~= nil then
+            rhs = stringfor(ast[2],tblcpy)
+        end
+        local output = "local " .. lhs
+        if ast[2].tag ~= nil then
+            output = output .. "=" .. rhs .. ";"
+        end
+        return output
+    end,
+    ["VarList"] = function(ast,tbl)
+        local vars = {}
+        for k = 1,#ast do
+            vars[#vars + 1] = stringfor(ast[k],tbl)
+        end
+        return table.concat(vars,",")
+    end,
+    ["Set"] = function(ast,tbl)
+        local lhs = {}
+        for k = 1,#ast[1] do
+            lhs[#lhs + 1] = stringfor(ast[1],tbl)
+        end
+        local rhs = {}
+        for k = 1,#ast[2] do
+            rhs[#rhs + 1] = stringfor(ast[2],tbl)
+        end
+        local ostring = table.concat(lhs,",")
+        ostring = ostring .. "=" .. table.concat(rhs,",")
+        return ostring .. ";"
+    end,
+    ["Label"] = function(ast,tbl)
+        if tbl.nids[ast[1]] == nil then
+            local nextvar = getnextvarname(tbl.lname)
+            tbl.lname = nextvar
+            tbl.nids[ast[1]] = nextvar
+        end
+        return "::" .. tbl.nids[ast[1]] .. "::"
+    end,
+    ["Goto"] = function(ast,tbl)
+        if tbl.nids[ast[1]] == nil then
+            local nextvar = getnextvarname(tbl.lname)
+            tbl.lname = nextvar
+            tbl.nids[ast[1]] = nextvar
+        end
+        return " goto " .. tbl.nids[ast[1]]
+    end,
+    ["Function"] = function(ast,tbl)
+        local funcargs = stringfor(ast[1],tbl)
+        local code = stringfor(ast[2],tbl)
+        return table.concat({" function(",funcargs,")",code," end "})
+    end,
+    ["Localrec"] = function(ast,tbl)
+        local ident
+        if tbl.ids[ast[1][1]] ~= nil then
+            ident = tbl.ids[ast[1][1]]
+        else
+            local newvar = getnextvarname(tbl.lname)
+            tbl.lname = newvar
+            tbl.ids[ast[1][1][1]] = newvar
+            ident = newvar
+        end
+        local argstr = stringfor(ast[2][1][1],tbl)
+        local expr = stringfor(ast[2][1][2],tbl)
+        return table.concat({" local function ",ident,"(",argstr,")",expr," end "})
+    end,
+    ["Continue"] = function(ast,tbl)
+        return " continue "
+    end,
+    ["While"] = function(ast,tbl)
+        local expr = stringfor(ast[1],tbl)
+        local block = stringfor(ast[2],tbl)
+        local output = table.concat(" while " , expr , " do " , block , " end ")
+        return output
+    end,
+    ["Break"] = function(ast,tbl)
+        return " break "
+    end,
+    ["Block"] = function(ast,oldtbl)
+        local tbl = deepcopy(oldtbl)
+        oldtbl.block = true
+        local codeblocks = {}
+        for k = 1,#ast do
+            codeblocks[#codeblocks + 1] = stringfor(ast[k],tbl)
+        end
+        local code = table.concat(codeblocks)
+        local lhss,rhss = {},{}
+        for k,v in pairs(tbl.strings) do
+            if oldtbl.strings[k] ~= tbl.strings[k] then
+                lhss[#lhss + 1] = v
+                rhss[#rhss + 1] = string.format("%q",k)
+            end
+        end
+        local inits = ""
+        local lhs = " local " .. table.concat(lhss,",")
+        local rhs = table.concat(rhss,",")
+        if string.len(rhs) > 0 then
+            inits = table.concat({lhs, "=", rhs, ";"})
+        end
+        return inits .. code
+    end,
+}
+
+local function stringfor(ast,tbl)
+    if syntax[ast.tag] ~= nil then
+        return syntax[ast.tag](ast,tbl)
+    else
+        error("Attempted to use unknown tag type:" .. ast.tag)
+    end
+end
+
+--Removes extra spaces and duplicated ; from a string
+local function removespaces(str)
+    local removables = {
+        {"%s*%)%s*","%)"}, --Spaces before or after )
+        {"%s*%(%s*","%("}, --Spaces before or after (
+        {"%s*;%s*",";"}, --Spaces before or after ;
+        {"%s*,%s*",","}, --Spaces before or after ,
+        {";+",";"}, --Multiple ; in a row
+        {"^%s*",""}, --Spaces at the beginning of the file
+        {"%s*$",""}, --Spaces at the end of the file
+        {"%s+"," "}, --Multiple spaces in a row
+    }
+    --Order is important
+    for k,v in ipairs(removables) do
+        str = string.gsub(str,v[1],v[2])
+    end
+    return str
+end
+
+glum.minify = function(str, name)
+    local ast, error_msg = parser.parse(str, name)
+    if not ast then
+        error(error_msg)
+    end
+    local localvar = {
+        ["strings"] = {},
+        ["ids"] = {},
+        ["lname"] = "",
+        ["nids"] = {},
+    }
+    return removespaces(stringfor(ast,localvar))
+end
+
+return glum