feat(syntax): eval statement

4 files changed, 23 insertions, 14 deletions

diff --git a/example/input.txt b/example/input.txt
index a530f47..7233dc7 100644
--- a/example/input.txt
+++ b/example/input.txt
@@ -1,8 +1,7 @@
-:a = 7
-:b = 4
-:res = (:a + :b) * 10 / 2
+:a = 7;; :b = 4;;
+(:a + :b) * 10 / 2
 
 :x = 20
 :y = 3
 :z = 6
-:val = 10 + :z / :y * :x / 4
+10 + :z / :y * :x / 4
diff --git a/lib/elixir_math_parser.ex b/lib/elixir_math_parser.ex
index 8d5bcc9..4da4271 100644
--- a/lib/elixir_math_parser.ex
+++ b/lib/elixir_math_parser.ex
@@ -49,6 +49,13 @@ defmodule ElixirMathParser do
     end
   end
 
+  defp evaluate_tree([{:eval, expr} | tail], state) do
+    with {:ok, expr} <- reduce_to_value(expr, state) do
+      IO.puts(expr)
+      evaluate_tree(tail, state)
+    end
+  end
+
   defp evaluate_tree([], state) do
     {:ok, state}
   end
diff --git a/lib/main.ex b/lib/main.ex
index f1f0a20..ad657ca 100644
--- a/lib/main.ex
+++ b/lib/main.ex
@@ -7,9 +7,10 @@ defmodule ElixirMathParser.Main do
   def process_parse({:ok, tree}) do
     IO.puts("\nParse tree")
     IO.inspect(tree, pretty: true)
-    state = ElixirMathParser.process_tree(tree)
-    IO.puts("\nFinal state")
-    IO.inspect(state, pretty: true)
+    case ElixirMathParser.process_tree(tree) do
+      {:ok, _} -> :ok 
+      {:error, reason} -> reason
+    end
   end
 
   def main(args) do
@@ -20,9 +21,10 @@ defmodule ElixirMathParser.Main do
 
     {:ok, tokens, line} = :elixir_math_parser_lexer.string(String.to_charlist(text))
     IO.puts("Parsed #{filename}, stopped at line #{line}")
-    IO.puts("\nTokens:")
-    IO.inspect(tokens, pretty: true)
 
-    process_parse(:elixir_math_parser.parse(tokens))
+    res = process_parse(:elixir_math_parser.parse(tokens))
+    if res != :ok do
+      IO.puts(res)
+    end
   end
 end
diff --git a/src/elixir_math_parser.yrl b/src/elixir_math_parser.yrl
index 3ec4946..17b46ad 100644
--- a/src/elixir_math_parser.yrl
+++ b/src/elixir_math_parser.yrl
@@ -31,11 +31,12 @@ Left 600 '('.
 
 root -> statements : '$1'.
 
-statements -> statement : '$1'.
-statements -> statement statements : lists:merge('$1', '$2').
-statements -> statement ';;' statements : lists:merge('$1', '$3').
+statements -> statement : ['$1'].
+statements -> statement statements : ['$1'|'$2'].
+statements -> statement ';;' statements : ['$1'|'$3'].
 
-statement -> atom '=' expr : [{assign, '$1', '$3'}].
+statement -> atom '=' expr : {assign, '$1', '$3'}.
+statement -> expr : {eval, '$1'}.
 
 expr -> int : unwrap('$1').
 expr -> atom : '$1'.