fix: make transpiler experimental

NOTES.md

@@ -66,7 +66,7 @@ Check out the new [sysinfo.ena](./example/sysinfo.ena) program that shows variou
 The design choices remain consistent with the principles discussed in the lectures and exercises,
 adhering to established best practices and prioritizing simplicity in the syntax of common programming languages.
 
-An additional feature is the transpiler option, which allows for the conversion of Ena code into Lua code.
+An additional feature is the transpiler option (for testing only, functionality is not fully developed and may be inconsistent.), which allows for the conversion of Ena code into Lua code.
 This enables users to visualize how the Ena code would appear in widely recognized programming languages.
 Additionally, the Lua code can be further transpiled into languages such as Python, Typescript, and more.
 
@@ -97,7 +97,7 @@ options are:
 | --trace | -t | Trace the program. |
 | --result | -r | Show the result. |
 | --pegdebug | -p | Run the PEG debugger. |
-| --transpile | -tp | Transpile to Lua. |
+| --transpile | -tp | Transpile to Lua. (experimental) |
 | --translate | -tr | Translate messages to Georgian. |
 
 For example:
@@ -150,7 +150,7 @@ Check out the [Issues](https://github.com/pgagnidze/ena/issues) for more details
 - Added the CI/CD for the tests to ensure stability and quality.
 - Developed a CLI (Command-Line Interface) tool that offers convenient options for users to interact with the project.
 - Created a syntax highlighter specifically for Visual Studio Code, enhancing the code editing experience for users working with the project.
-- Implemented the transpiler option, allowing the conversion of Ena code into Lua code, which enables users to evaluate and utilize the code in a more established programming language.
+- Implemented the transpiler option (experimental), allowing the conversion of Ena code into Lua code, which enables users to evaluate and utilize the code in a more established programming language.
 
 ## References
 

README.md

@@ -35,7 +35,7 @@ options-ები მოიცავს:
 | --trace | -t | მიჰყევით პროგრამის მსვლელობას. |
 | --result | -r | აჩვენეთ შედეგი. |
 | --pegdebug | -p | გაუშვით PEG დებაგერი. |
-| --transpile | -tp | ტრანსპილაცია Lua-ში. |
+| --transpile | -tp | ტრანსპილაცია Lua-ში. (ექსპერიმენტული) |
 | --translate | -tr | თარგმნეთ წერილები ქართულ ენაზე. |
 
 მაგალითისთვის:

ena.lua

@@ -160,12 +160,12 @@ if show.result then
     io.stdout:write((show.translate and translator.success.showResult or "Result") .. ":\n", tostring(result), "\n\n")
 end
 
--- transpile --
+-- transpile: experimental --
 if show.transpile then
     local transpiledCode = transpiler.transpile(ast)
     io.stdout:write(
-        (show.transpile and translator.success.showTranspile or "Transpiled") .. ":\n",
+        (show.translate and translator.success.showTranspile or "Transpiled") .. ":\n",
         tostring(transpiledCode),
-        "\n\n"
+        "\n"
     )
 end

ena/transpiler.lua

@@ -1,3 +1,9 @@
+--[[
+    This transpiler is experimental. It supports the following AST nodes:
+    - function, functionCall, block, if, while, arrayElement, newArray, statementSequence, assignment, local
+    - boolean, number, string, nil, print, exec, variable, emptyStatement, binaryOp, unaryOp, return
+]]
+
 local module = {}
 local Transpiler = {}
 local translator = require "ena.lang.translator"
@@ -78,20 +84,14 @@ local handlers = {
         local index = transpiler:transpile(node.index, indentLevel)
         return array .. "[" .. index .. "]"
     end,
+    -- We use 'size' as a string expression to dynamically determine the size of the table
+    -- We use a metatable to provide a default value for all indices up to size
+    -- Note: This assumes that 'size' is a valid Lua expression and that it evaluates to a number
     ["newArray"] = function(transpiler, node, indentLevel, indent)
         local size = transpiler:transpile(node.size, indentLevel)
         local initialValue = transpiler:transpile(node.initialValue, indentLevel)
         if type(size) == "string" then
-            -- We use 'size' as a string expression to dynamically determine the size of the table
-            -- We use a metatable to provide a default value for all indices up to size
-            -- Note: This assumes that 'size' is a valid Lua expression and that it evaluates to a number
-            return "(function()\n" ..
-                indent .. "    local t = setmetatable({}, {__index = function() return " .. initialValue .. " end})\n" ..
-                indent .. "    for i = 1, " .. size .. " do\n" ..
-                indent .. "        t[i] = " .. initialValue .. "\n" ..
-                indent .. "    end\n" ..
-                indent .. "    return t\n" ..
-                indent .. "end)()"
+            return "newArray(" .. size .. ", " .. initialValue .. ")"
         end
         local arrayElements = {}
         for _ = 1, size do
@@ -130,12 +130,8 @@ local handlers = {
         return indent .. "print(" .. transpiler:transpile(node.toPrint, indentLevel) .. ")"
     end,
     ["exec"] = function(transpiler, node, indentLevel, indent)
-        return "(function()\n" ..
-            indent .. '    local command = ' .. transpiler:transpile(node.command, indentLevel) .. '\n' ..
-            indent .. '    local file = assert(io.popen(command, "r"), "failed to execute command " .. command)\n' ..
-            indent .. '    local output = file:read("*all")\n' ..
-            indent .. '    return string.gsub(output, "^%s*(.-)%s*$", "%1")\n' ..
-            indent .. "end)()"
+        local command = transpiler:transpile(node.command, indentLevel)
+        return "exec(" .. command .. ")"
     end,
     ["variable"] = function(transpiler, node, indentLevel, indent)
         return node.value
@@ -155,10 +151,20 @@ local handlers = {
             -- Check if either operand is a string or a variable
             if node.firstChild.tag == "string" or node.firstChild.tag == "variable" or
                node.secondChild.tag == "string" or node.secondChild.tag == "variable" then
-                -- Generate code that checks the type of the operands at runtime
-                return "(function() local a = " .. transpiler:transpile(node.firstChild, indentLevel) .. 
-                       "; local b = " .. transpiler:transpile(node.secondChild, indentLevel) .. 
-                       "; if type(a) == 'string' or type(b) == 'string' then return a .. b else return a + b end end)()"
+                -- Traverse the binary tree to collect all the operands of + operations
+                local args = {}
+                local stack = {node}
+                while #stack > 0 do
+                    local current = table.remove(stack)
+                    if current.tag == "binaryOp" and current.op == "+" then
+                        table.insert(stack, current.firstChild)
+                        table.insert(stack, current.secondChild)
+                    else
+                        table.insert(args, 1, transpiler:transpile(current, indentLevel))
+                    end
+                end
+                -- Join the operands together in a single call to addOrConcat
+                return "addOrConcat(" .. table.concat(args, ", ") .. ")"
             end
         end
         return transpiler:transpile(node.firstChild, indentLevel) ..
@@ -200,15 +206,52 @@ end
 function module.transpile(ast)
     local transpiler = Transpiler:new()
     local luaCodeParts = {}
+    table.insert(
+        luaCodeParts,
+        [[
+function newArray(size, initialValue)
+    local t = setmetatable({}, {__index = function() return initialValue end})
+    for i = 1, size do
+        t[i] = initialValue
+    end
+    return t
+end
+
+function exec(command)
+    local file = assert(io.popen(command, "r"), "failed to execute command " .. command)
+    local output = file:read("*all")
+    return string.gsub(output, "^%s*(.-)%s*$", "%1")
+end
+
+function addOrConcat(...)
+    local args = {...}
+    local result = args[1]
+    for i = 2, #args do
+        if type(result) == 'string' or type(args[i]) == 'string' then
+            result = result .. args[i]
+        else
+            result = result + args[i]
+        end
+    end
+    return result
+end
+
+]]
+    )
     for _, node in ipairs(ast) do
         table.insert(luaCodeParts, transpiler:transpile(node))
     end
-    table.insert(luaCodeParts, "\nmain()")
+    table.insert(luaCodeParts, [[
+
+main()
+
+-- EXPERIMENTAL: This transpiler is for testing only. Functionality is not fully developed and may be inconsistent. --
+
+]])
     local luaCode = table.concat(luaCodeParts, "")
     local georgianCharacters = replaceGeorgianCharacters(luaCode)
     local replacedMain = string.gsub(georgianCharacters, "mthavari", "main")
     return replacedMain
-
 end
 
 return module