WIP STUFF

.gitignore

@@ -30,4 +30,4 @@ lytlang-*.tar
 *.swp
 
 # Ignore compiled Erlang files
-/src/lytlang.erl
+/src/*.erl

README.md

@@ -1,8 +1,6 @@
 # Lytlang
 
-Lytlang's goal is to enable you to write Elixir code more tersely and is itself
-written in Elixir. Its syntax is a terrible merging of Elm, CoffeeScript,
-Elixir, a sprinkling of Rust, and some made-up crap. Here's a rough preview:
+Lytlang is an opinionated way to write more readable Elixir code.
 
 ```
 !module Leetcode

lib/lytlang.ex

@@ -1,31 +1,83 @@
 defmodule Lytlang do
-  @moduledoc """
-  Documentation for Lytlang.
-  """
+  def eval(string) do
+    {value, _} =
+      string
+      |> from_lytlang()
+      |> IO.inspect()
+      |> Code.eval_quoted()
+      |> IO.inspect()
 
-  @doc """
-  Hello world.
-
-  ## Examples
-
-      iex> Lytlang.hello()
-      :world
-
-  """
-  def hello do
-    :world
+    value
   end
 
-  @doc """
-  Echo.
-
-  ## Examples
-
-      iex> Lytlang.echo("world")
-      "world"
-
-  """
-  def echo(s) do
-    s
+  def from_lytlang(string, binding \\ [], opts \\ []) do
+    string |> String.to_charlist() |> tokenize() |> parse() |> transform(binding, opts)
   end
+
+  def tokenize(string) do
+    {:ok, tokens, _} =
+      :lytlang_lexer.string(string)
+      |> IO.inspect()
+
+    tokens
+  end
+
+  def parse(tokens) do
+    {:ok, tree} =
+      :lytlang_parser.parse(tokens)
+      |> IO.inspect()
+
+    tree
+  end
+
+  def transform(ast, binding \\ [], opts \\ [])
+
+  def transform([] = _expr_list, _binding, _opts), do: []
+
+  def transform([expr | rest] = _expr_list, binding, opts) do
+    [transform(expr, binding, opts) | transform(rest, binding, opts)]
+  end
+
+  def transform({:binary_op, _line, op, left, right}, binding, _) do
+    {op, binding, [transform(left), transform(right)]}
+  end
+
+  def transform({:unary_op, line, op, left}, _, _) do
+    {:op, line, op, transform(left)}
+  end
+
+  def transform({:integer, _, n} = _expr, _, _), do: n
 end
+
+"""
+-module(elixir).
+-export([eval/1, from_elixir/1, from_erlang/1]).
+
+eval(String) ->
+  {value, Value, _} = erl_eval:expr(from_elixir(String), []),
+  Value.
+
+% Temporary to aid debugging
+from_elixir(String) ->
+  transform(parse(String)).
+
+% Temporary to aid debugging
+from_erlang(String) ->
+  {ok, Tokens, _} = erl_scan:string(String),
+  {ok, [Form]} = erl_parse:parse_exprs(Tokens),
+  Form.
+
+parse(String) ->
+        {ok, Tokens, _} = elixir_lexer:string(String),
+        {ok, ParseTree} = elixir_parser:parse(Tokens),
+        ParseTree.
+
+transform({ binary_op, Line, Op, Left, Right }) ->
+  {op, Line, Op, transform(Left), transform(Right)};
+
+transform({ unary_op, Line, Op, Right }) ->
+  {op, Line, Op, transform(Right)};
+
+
+transform({ integer, _, _ } = Expr) -> Expr.
+"""

lib/parser.ex

@@ -1,10 +0,0 @@
-defmodule Lytlang.Parser do
-  @doc """
-  Attempts to tokenize an input string to start_tag, end_tag, and char
-  """
-  @spec parse(binary) :: list
-  def parse(input) do
-    {:ok, tokens, _} = input |> to_char_list |> :lytlang.string()
-    tokens
-  end
-end

lib/transpiler.ex

@@ -1,95 +0,0 @@
-defmodule Lytlang.Transpiler do
-  @moduledoc """
-  Documentation for Lytlang.
-  """
-
-  @spec transpile_file(String.t()) :: String.t()
-  def transpile_file(file_path) do
-    file_path
-    |> File.read!()
-    |> transpile_block()
-  end
-
-  @doc """
-  Transpiler!
-
-  ## Examples
-
-      iex> Lytlang.Transpiler.transpile_block("!mod EmptyModule")
-      "defmodule EmptyModule do\\nend"
-
-      iex> Lytlang.Transpiler.transpile_block("!mod EmptyModule\\n\\tfn hello\\n\\t\\t:world")
-      "defmodule EmptyModule\\n\\tdef hello() do\\n\\t\\t:world\\n\\tend\\nend"
-
-  """
-  @spec transpile_block(String.t(), Keyword.t()) :: String.t()
-  def transpile_block(s, _opts \\ []) do
-    s
-    |> split_lines()
-    |> Enum.map(&tokenize/1)
-    |> IO.inspect(label: "Tokens")
-    |> build_ast()
-    |> IO.inspect(label: "AST")
-    |> ast_to_elixir()
-  end
-
-  def initial_ast_state() do
-    %{
-      ast: {:__global, []}
-    }
-  end
-
-  def build_ast(token_lines, state \\ nil)
-
-  def build_ast([], state), do: state.ast |> Enum.reverse()
-
-  def build_ast([line_tokens | rest], state) do
-    state =
-      if !state do
-        initial_ast_state()
-      else
-        state
-      end
-
-    ast = state.ast
-
-    state =
-      case line_tokens do
-        ["!mod", module_name | rest] ->
-          %{state | ast: [{:module, module_name, []} | ast]}
-
-        ["fn", fn_name | rest] ->
-          %{state | ast: [{:function, fn_name, []} | ast]}
-
-        expr ->
-          expr |> IO.inspect(label: "lyt expression")
-          %{state | ast: [expr |> Enum.join(" ") | ast]}
-      end
-
-    build_ast(rest, state)
-  end
-
-  def ast_to_elixir(s, state \\ %{elixir_code: []})
-
-  def ast_to_elixir([], state),
-    do: state.elixir_code |> Enum.filter(&(String.trim(&1) != "")) |> Enum.join("\n")
-
-  def ast_to_elixir([leaf | rest], state) do
-    child = fn {head, tail}, state -> [head | ast_to_elixir(rest, state)] ++ [tail] end
-
-    case leaf do
-      :global -> child.({"", ""}, state)
-      {:module, mod, []} -> child.({"defmodule #{mod} do", "end"}, state)
-      {:fn, fname, []} -> child.({"def #{fname} do", "end"}, state)
-      expr when is_binary(expr) -> [expr]
-    end
-  end
-
-  def split_lines(s) do
-    String.split(s, "\n", trim: true)
-  end
-
-  def tokenize(s) do
-    Regex.split(~r/\s/, s)
-  end
-end

src/lytlang.xrl

@@ -1,16 +0,0 @@
-Definitions.
-
-I = \t
-MODULE_DECL = module\s[a-zA-Z][a-zA-Z0-9_]*
-FILE_LEVEL_MODULE_DECL = !module\s([a-zA-Z][a-zA-Z0-9_]*)
-NUMBER = [0-9]+
-
-Rules.
-
-%% number
-{NUMBER} : {token, { number, TokenLine, list_to_integer(TokenChars) } }.
-{MODULE_DECL} : {token, { module_decl, TokenLine, TokenChars } }.
-{FILE_LEVEL_MODULE_DECL} : {token, { file_level_module_decl, TokenLine, TokenChars } }.
-[\s\n\r\t]+ : skip_token.
-
-Erlang code.

src/lytlang_lexer.xrl

@@ -0,0 +1,44 @@
+% Lexer syntax for the Elixir language done with leex
+% Copyright (C) 2011 Jose Valim
+
+Definitions.
+
+D = [0-9]
+U = [A-Z]
+L = [a-z]
+WS = [\s]
+
+Rules.
+
+{D}+\.{D}+ : { token, { float, TokenLine, list_to_float(TokenChars) } }.
+{D}+       : { token, { integer, TokenLine, list_to_integer(TokenChars) } }.
+({L}|_)({U}{L}{D}|_)* : { token, var(TokenChars, TokenLine) }.
+
+\+    : { token, { '+', TokenLine } }.
+-     : { token, { '-', TokenLine } }.
+\*    : { token, { '*', TokenLine } }.
+/     : { token, { '/', TokenLine } }.
+\(    : { token, { '(', TokenLine } }.
+\)    : { token, { ')', TokenLine } }.
+=     : { token, { '=', TokenLine } }.
+->    : { token, { '->', TokenLine } }.
+;     : { token, { ';', TokenLine } }.
+
+{Comment} : skip_token.
+{WS}+ : skip_token.
+% ({Comment}|{Whitespace})*(\n({Comment}|{Whitespace})*)+ : { token, { eol, TokenLine } }.
+
+Erlang code.
+
+var(Chars, Line) ->
+    Atom = list_to_atom(Chars),
+    case reserved_word(Atom) of
+        true -> {Atom, Line};
+        false -> {var, Line, Atom}
+    end.
+
+reserved_word('nil') -> true;
+reserved_word('true') -> true;
+reserved_word('false') -> true;
+reserved_word('module') -> true;
+reserved_word(_) -> false.

src/lytlang_parser.yrl

@@ -0,0 +1,90 @@
+Nonterminals
+	grammar
+	expr_list
+  expr
+	assign_expr
+  add_expr
+  mult_expr
+  unary_expr
+	fun_expr
+	body
+	stabber
+  max_expr
+  number
+  unary_op
+  add_op
+  mult_op
+  .
+
+Terminals
+  var float integer eol
+  '+' '-' '*' '/' '(' ')' '=' '->'
+  .
+
+Rootsymbol grammar.
+
+grammar -> expr_list : '$1'.
+grammar -> '$empty' : [].
+
+expr_list -> eol : [].
+expr_list -> expr : ['$1'].
+expr_list -> expr eol : ['$1'].
+expr_list -> eol expr_list : '$2'.
+expr_list -> expr eol expr_list : ['$1'|'$3'].
+
+expr -> assign_expr : '$1'.
+
+assign_expr -> add_expr '=' assign_expr :
+	{ match, ?line('$2'), '$1', '$3' }.
+
+assign_expr -> add_expr : '$1'.
+
+%% Arithmetic operations
+add_expr -> add_expr add_op mult_expr :
+  { binary_op, ?line('$1'), ?op('$2'), '$1', '$3' }.
+
+add_expr -> mult_expr : '$1'.
+
+mult_expr -> mult_expr mult_op unary_expr :
+  { binary_op, ?line('$1'), ?op('$2'), '$1', '$3' }.
+
+mult_expr -> unary_expr : '$1'.
+
+unary_expr -> unary_op max_expr :
+  { unary_op, ?line('$1'), ?op('$1'), '$2' }.
+
+unary_expr -> max_expr : '$1'.
+
+fun_expr -> stabber eol body :
+	{ 'fn', ?line('$1')
+	, { clauses, [ { clause, ?line('$1'), [], [], '$3' } ] }
+	}.
+
+fun_expr -> max_expr : '$1'.
+
+%% Minimum expressions
+max_expr -> number : '$1'.
+max_expr -> '(' expr ')' : '$2'.
+
+%% Numbers
+number -> float   : '$1'.
+number -> integer : '$1'.
+
+%% Unary operator
+unary_op -> '+' : '$1'.
+unary_op -> '-' : '$1'.
+ 
+%% Addition operators
+add_op -> '+' : '$1'.
+add_op -> '-' : '$1'.
+ 
+%% Multiplication operators
+mult_op -> '*' : '$1'.
+mult_op -> '/' : '$1'.
+ 
+Erlang code.
+ 
+-define(op(Node), element(1, Node)).
+-define(line(Node), element(2, Node)).
+-define(char(Node), element(3, Node)).
+

test/fixtures/example_projects/simple_app/app.lyt

@@ -1,24 +1,28 @@
-mod SimpleApp
-entry
-	:project
-		deps:
-      {:cowboy, "~> 2.6"}
-      {:plug, "~> 1.8"}
-      {:plug_cowboy, "~> 2.0"}
-	:app
-		[extra_applications: [:logger]]
+!project SimpleApp simple_app
+	# should generate a SimpleApp.MixProject_ module
+	version: "0.1.0"
+	elixir: "~> 1.8"
+	lytl: "~> 0.1"
+	start_permanent: Mix.env() == prod
+	extra_applications: [logger]
+	deps: []
 
-import Plug.Conn
+!module
+	# uses project's name as module if not module name specified
+	import Plug.Conn
 
-fn init default_options
-	IO.puts "initializing plug"
-	default_options
+init = opts -> IO.puts "initializing plug"; opts
 
-fn call conn:Plug.Conn.t() _options = []
+call = conn _options = [] ->
 	IO.puts "calling plug"
-
 	conn
 	|> put_resp_content_type "text/plain"
 	|> send_resp 200 "Hello world"
 
+long_fn =
+	arg1
+	arg2
+	arg3
+	->
+
 # in lytx run `Plug.Adapters.Cowboy.http SimpleApp []`

test/lytlang_test.exs

@@ -1,9 +1,21 @@
 defmodule LytlangTest do
   use ExUnit.Case
   doctest Lytlang
-  doctest Lytlang.Transpiler
 
-  test "greets the world" do
-    assert Lytlang.hello() == :world
+  test "arithmetic" do
+    [
+      {"2 + 3 + 8", 13},
+      {"2 * 3 + 8", 14},
+      {"2 + 3 * 8", 26},
+      {"(2 + 3) * 8", 40},
+      {"2 * (3 + 8)", 22},
+      {"2 + (3 * 8)", 26},
+      {"8 - 3", 5},
+      {"8 / 4", 2.0},
+      {"2 + 3", 5}
+    ]
+    |> Enum.map(fn {string, val} ->
+      assert Lytlang.eval(string) == val
+    end)
   end
 end