diff --git a/kaitai/expr.rkt b/kaitai/expr.rkt
index 0b1eac6..67a05a3 100644
--- a/kaitai/expr.rkt
+++ b/kaitai/expr.rkt
@@ -1,12 +1,12 @@
 #lang racket/base
 
-(require racket/function racket/match racket/set
+(require racket/function racket/list racket/match racket/set
          parser-tools/lex
          (prefix-in : parser-tools/lex-sre)
          parser-tools/yacc)
 
 (define-tokens kaitai-expr [boolean number string identifier])
-(define-empty-tokens kaitai-empty [eof + - * / % < <= > >= == != << >> & pipe ^ not and or ? :
+(define-empty-tokens kaitai-sym [eof + - * / % < <= > >= == != << >> & pipe ^ not and or ? :
                                    lparen rparen lbracket comma dot rbracket])
 
 (define (kaitai-numstr->number str)
@@ -18,7 +18,6 @@
 
 (define (kaitai-subst-string str)
   ;; racket's built in string translation works fine
-  (printf "uwu ~s\n" str)
   (read (open-input-string
           (string-append "\"" (substring str 1 (sub1 (string-length str))) "\""))))
 
@@ -66,11 +65,61 @@
     ["]" (token-rbracket)]
     [(:: (:+ (:or alphabetic "_"))
          (:* (:or alphabetic numeric "_" "::")))
-     (token-identifier lexeme)]
+     (token-identifier (string->symbol lexeme))]
     [(eof) (token-eof)]))
 
-(let ([input (open-input-string "_root._io.size.to_i & 0x08000000 != 'abc\\'c' 0 + code == block_type::int32 ? 4 : 8")])
-  (let loop ()
-    (match (kaitai-lexer input)
-      [(? (curry equal? (token-eof))) (void)]
-      [x (printf "~v\n" x) (loop)])))
+(define kaitai-parser
+  (parser
+    [start exp]
+    [end eof]
+    [error (lambda (tok-ok? tok-name tok-value)
+             (error "parser error" tok-ok? tok-name tok-value))]
+    [tokens kaitai-expr kaitai-sym]
+    [precs (left comma)
+           (right ? :)
+           (left and or)
+           (left & pipe ^)
+           (left < <= > >= != ==)
+           (left << >>)
+           (left + -)
+           (left * / %)
+           (right not)
+           (left dot lparen rparen lbracket rbracket)]
+    [grammar
+      (exp [(number) $1]
+           [(string) $1]
+           [(boolean) $1]
+           [(identifier) $1]
+           [(lbracket apply-args rbracket) (cons 'array $2)]
+           [(exp dot identifier) (list 'get $1 $3)]
+           [(exp lparen apply-args rparen) `(apply ,$1 ,@$3)]
+           [(exp * exp) (list '* $1 $3)]
+           [(exp / exp) (list '/ $1 $3)]
+           [(exp % exp) (list '% $1 $3)]
+           [(exp + exp) (list '+ $1 $3)]
+           [(exp - exp) (list '- $1 $3)]
+           [(exp < exp) (list '< $1 $3)]
+           [(exp <= exp) (list '<= $1 $3)]
+           [(exp > exp) (list '> $1 $3)]
+           [(exp >= exp) (list '>= $1 $3)]
+           [(exp != exp) (list '!= $1 $3)]
+           [(exp == exp) (list '== $1 $3)]
+           [(exp >> exp) (list '>> $1 $3)]
+           [(exp << exp) (list '<< $1 $3)]
+           [(exp & exp) (list '& $1 $3)]
+           [(exp pipe exp) (list 'pipe $1 $3)]
+           [(exp ^ exp) (list '^ $1 $3)]
+           [(exp and exp) (list 'and $1 $3)]
+           [(exp or exp) (list 'or $1 $3)]
+           [(not exp) (list 'not $2)]
+           [(exp ? exp : exp) (list 'if $1 $3 $5)]
+           [(lparen exp rparen) $2])
+      (apply-args
+        [(exp) (list $1)]
+        [(exp comma apply-args) (cons $1 $3)])
+      ]))
+
+(define test2 "true and 'a' != 'b' ? 1 : ('hello' + 'world').substring(2, 3)")
+
+(let ([input (open-input-string test2)])
+  (kaitai-parser (lambda () (kaitai-lexer input))))