Initial state - basic lexer + parser + interpreter

lib/parser.mly

@@ -0,0 +1,34 @@
+%{
+    open Ast
+%}
+
+%token <int> INT
+%token <float> DOUBLE
+%token <string> SYM
+%token <string> STR
+%token LPAREN
+%token RPAREN
+%token QUOTE
+%token EOF
+
+%start <Ast.lisp_val option> prog
+%%
+
+prog:
+    | EOF { None }
+    | e = expr { Some e }
+    ;
+
+expr:
+    | i = INT { LInt i }
+    | d = DOUBLE {LDouble d}
+    | s = SYM { LSymbol s }
+    | s = STR { LString (String.uppercase_ascii s) }
+    | LPAREN; l = lisp_list_rest { l }
+    | QUOTE; e = expr { LQuoted e}
+    ;
+
+lisp_list_rest:
+    | RPAREN { LNil }
+    | e = expr; lr = lisp_list_rest { LCons (e, lr) }
+    ;