diff --git a/README.md b/README.md
index 2b8a16c2..b95d10af 100644
--- a/README.md
+++ b/README.md
@@ -37,13 +37,23 @@ You may also download a binary from [Github](https://github.com/borkdude/babashk
 ## Usage
 
 The first argument to `bb` is the form to be executed. There is one special
-variable, `*in*`.
+variable, `*in*` which is EDN that is piped from stdin.
 
 If the first argument is `--version`, then `bb` will print the version and exit.
+If the first argument is `--raw`, then `bb` will interpret stdin as string input.
 
 Examples:
 
 ``` shellsession
+$ ls | bb --raw '*in*'
+["LICENSE" "README.md" "bb" "doc" "pom.xml" "project.clj" "reflection.json" "resources" "script" "src" "target" "test"]
+
+$ ls | bb --raw '*in*' | bb '(count *in*)'
+11
+
+$ ls | bb --raw '*in*' | bb '(count *in*)'
+11
+
 $ echo 1 | bb '(inc *in*)'
 2
 
@@ -60,6 +70,17 @@ $ echo '"babashka"' | bb '(re-find (re-pattern "b.b.*") *in*)'
 "babashka"
 ```
 
+Functions are written using the reader tag `#bb/fn`. Currently up to three
+arguments are supported.
+
+``` shellsession
+$ echo '' | bb '(#bb/fn (+ %1 %2) 1 2)'
+3
+
+$ ls | bb --raw '*in*' | bb '(filterv #bb/fn (re-find (re-pattern "reflection") %) *in*)'
+["reflection.json"]
+```
+
 ## Test
 
 Test the JVM version:
diff --git a/src/babashka/interpreter.clj b/src/babashka/interpreter.clj
index 5e61f821..aa3a18de 100644
--- a/src/babashka/interpreter.clj
+++ b/src/babashka/interpreter.clj
@@ -1,6 +1,7 @@
 (ns babashka.interpreter
   {:no-doc true}
-  (:refer-clojure :exclude [comparator]))
+  (:refer-clojure :exclude [comparator])
+  (:require [clojure.walk :refer [postwalk]]))
 
 (defn safe-nth [x n]
   (try (nth x n)
@@ -8,7 +9,7 @@
          nil)))
 
 (def syms '(= < <= >= + +' - * /
-              aget alength assoc assoc-in
+              aget alength apply assoc assoc-in
               bit-set bit-shift-left bit-shift-right bit-xor boolean boolean? booleans boolean-array butlast
               char char? conj cons contains? count
               dec dec' decimal? dedupe dissoc distinct disj drop
@@ -17,15 +18,15 @@
               first float? floats fnil
               identity inc int-array iterate
               juxt
-              filter find
+              filter filterv find
               last line-seq
               keep keep-indexed keys
               map map-indexed mapcat merge merge-with munge
-              newline not= num
+              name newline not= num
               neg? nth nthrest
               peek pos?
               re-seq re-find re-pattern rest reverse
-              safe-nth set? sequential? some?
+              safe-nth set? sequential? some? str
               take take-last take-nth tree-seq type
               unchecked-inc-int unchecked-long unchecked-negate unchecked-remainder-int
               unchecked-subtract-int unsigned-bit-shift-right unchecked-float
@@ -37,7 +38,7 @@
 #_(def all-syms
   '#{when-first while if-not when-let inc' cat StackTraceElement->vec flush take-while vary-meta <= alter -' if-some conj! repeatedly zipmap reset-vals! alter-var-root biginteger remove * re-pattern min pop! chunk-append prn-str with-precision format reversible? shutdown-agents conj bound? transduce lazy-seq *print-length* *file* compare-and-set! *use-context-classloader* await1 let ref-set pop-thread-bindings interleave printf map? -> defstruct *err* assert-same-protocol get doto identity into areduce long double volatile? definline nfirst meta find-protocol-impl bit-and-not *default-data-reader-fn* var? method-sig unchecked-add-int unquote-splicing hash-ordered-coll future reset-meta! Vec cycle fn seque empty? short definterface add-tap filterv hash quot ns-aliases read unchecked-double key longs not= string? uri? aset-double unchecked-multiply-int chunk-rest pcalls *allow-unresolved-vars* remove-all-methods ns-resolve as-> aset-boolean trampoline double? when-not *1 vec *print-meta* when int map-entry? ns-refers rand second vector-of hash-combine > replace int? associative? unchecked-int set-error-handler! inst-ms* keyword? force bound-fn* namespace-munge group-by prn extend unchecked-multiply some->> default-data-readers ->VecSeq even? unchecked-dec Inst tagged-literal? double-array in-ns create-ns re-matcher defn ref bigint extends? promise aset-char rseq ex-cause construct-proxy agent-errors *compile-files* ex-message *math-context* float pr-str concat aset-short set-agent-send-off-executor! ns symbol to-array-2d mod amap pop use VecNode unquote declare dissoc! reductions aset-byte indexed? ref-history-count - assoc! hash-set reduce-kv or cast reset! name ffirst sorted-set counted? byte-array IVecImpl tagged-literal println extend-type macroexpand-1 assoc-in char-name-string bit-test defmethod requiring-resolve EMPTY-NODE time memoize alter-meta! future? zero? simple-keyword? require unchecked-dec-int persistent! nnext add-watch not-every? class? rem agent-error some future-cancelled? memfn neg-int? struct-map drop *data-readers* nth sorted? nil? extend-protocol split-at *e load-reader random-sample cond-> dotimes select-keys bit-and bounded-count update list* reify update-in prefer-method aset-int *clojure-version* ensure-reduced *' instance? with-open mix-collection-hash re-find run! val defonce unchecked-add loaded-libs ->Vec bytes? not with-meta unreduced the-ns record? type identical? unchecked-divide-int ns-name max-key *unchecked-math* defn- *out* file-seq agent ns-map set-validator! ident? defprotocol swap! vals unchecked-subtract tap> *warn-on-reflection* sorted-set-by sync qualified-ident? assert *compile-path* true? release-pending-sends print empty remove-method *in* print-ctor letfn volatile! / read-line reader-conditional? bit-or clear-agent-errors vector proxy-super >= drop-last not-empty distinct partition loop add-classpath bit-flip long-array descendants merge accessor integer? mapv partition-all partition-by numerator object-array with-out-str condp derive load-string special-symbol? ancestors subseq error-handler gensym cond ratio? delay? intern print-simple flatten doubles halt-when with-in-str remove-watch ex-info ifn? some-> nat-int? proxy-name ns-interns all-ns find-protocol-method subvec for binding partial chunked-seq? find-keyword replicate min-key reduced char-escape-string re-matches array-map unchecked-byte with-local-vars ns-imports send-off defmacro every-pred keys rationalize load-file distinct? pos-int? extenders unchecked-short methods odd? ->ArrayChunk float-array *3 alias frequencies read-string proxy rsubseq inc get-method with-redefs uuid? bit-clear filter locking list + split-with aset ->VecNode keyword *ns* destructure *assert* defmulti chars str next hash-map if-let underive ref-max-history Throwable->map false? *print-readably* ints class some-fn case *flush-on-newline* to-array bigdec list? simple-ident? bit-not io! xml-seq VecSeq byte max == *agent* lazy-cat comment parents count supers *fn-loader* ArrayChunk sorted-map-by apply interpose deref assoc rational? transient clojure-version chunk-cons comparator sorted-map send drop-while proxy-call-with-super realized? char-array resolve compare complement *compiler-options* *print-dup* defrecord with-redefs-fn sequence constantly get-proxy-class make-array shorts completing update-proxy unchecked-negate-int hash-unordered-coll repeat unchecked-inc nthnext and create-struct get-validator number? await-for chunk-next print-str not-any? into-array qualified-symbol? init-proxy chunk-buffer seqable? symbol? when-some unchecked-char ->> future-cancel var-get commute coll? get-in fnext denominator bytes gen-and-load-class refer-clojure})
 
-(declare var-lookup)
+(declare var-lookup apply-fn)
 
 (defmacro define-lookup []
   `(defn ~'var-lookup [sym#]
@@ -53,17 +54,33 @@
   [expr in]
   (cond
     (= '*in* expr) in
+    (symbol? expr) (var-lookup expr)
     (list? expr)
     (if-let [f (first expr)]
-      (if-let [v (or (var-lookup f))]
-        (apply v (map #(interpret % in) (rest expr)))
-        (if (or (symbol? f) (keyword? f))
-          (get in f)
+      (if-let [v (var-lookup f)]
+        (apply-fn v in (rest expr))
+        (if (ifn? f)
+          (apply-fn f in (rest expr))
           nil))
       expr)
     :else
     expr))
 
+(defn read-fn [form]
+  ^:bb/fn
+  (fn [& [x y z]]
+    (postwalk (fn [elt]
+                (case elt
+                  % x
+                  %1 x
+                  %2 y
+                  %3 z
+                  (interpret elt x))) form)))
+
+(defn apply-fn [f in args]
+  (let [args (map #(interpret % in) args)]
+    (apply f args)))
+
 ;;;; Scratch
 
 (comment
diff --git a/src/babashka/main.clj b/src/babashka/main.clj
index 5324b919..a51ec6ca 100644
--- a/src/babashka/main.clj
+++ b/src/babashka/main.clj
@@ -9,6 +9,11 @@
 
 (set! *warn-on-reflection* true)
 
+(defn read-edn [s]
+  (edn/read-string
+   {:readers *data-readers*}
+   s))
+
 (defn- parse-opts [options]
   (let [opts (loop [options options
                     opts-map {}
@@ -22,19 +27,25 @@
                           (update opts-map current-opt conj opt)
                           current-opt))
                  opts-map))
-        version (boolean (get opts "--version"))]
-    {:version version}))
+        version (boolean (get opts "--version"))
+        raw (boolean (get opts "--raw"))]
+    {:version version
+     :raw raw}))
 
 (defn -main
   [& args]
-  (let [{:keys [:version]} (parse-opts args)]
+  (let [{:keys [:version :raw]} (parse-opts args)]
     (cond version
       (println (str/trim (slurp (io/resource "BABASHKA_VERSION"))))
       :else
-      (let [expr (edn/read-string (first args))
+      (let [expr (if raw (second args) (first args))
+            expr (read-edn expr)
             in (slurp *in*)
-            edn (edn/read-string in)]
-        (prn (i/interpret expr edn))))))
+            in (if raw
+                 (str/split in #"\s")
+                 (read-edn (format "[%s]" in)))
+            in (if (= 1 (count in)) (first in) in)]
+        (prn (i/interpret expr in))))))
 
 ;;;; Scratch
 
diff --git a/src/data_readers.clj b/src/data_readers.clj
new file mode 100644
index 00000000..65dead1b
--- /dev/null
+++ b/src/data_readers.clj
@@ -0,0 +1 @@
+{bb/fn babashka.interpreter/read-fn}