[mod] Rename "middleware" -> "transform" (xfn)

Users caught by this change should receive a clear compile-time error.

Apologies for the nuissance!! This change is part of a final review
of names before the release of v1 final.

Motivations:

  - "xfn" is a lot shorter than "middleware", making it more
    convenient to use at signal calls, compare:

    (log! {:middleware my-fn} "msg")
    (log! {:xfn my-fn} "msg"}

  - "middleware" was originally chosen to match Timbre's terminology,
    but actually carries some misleading connotations that in hindsight
    are probably better avoided while we still have the chance to change
    this.

README.md

@@ -113,15 +113,14 @@ It enables you to write code that is **information-verbose by default**.
 ;; Set minimum level for `event!` signals for particular ns pattern
 (t/set-min-level! :event "taoensso.sente.*" :warn)
 
-;; Use middleware to:
+;; Use transforms (xfns) to filter and/or arbitrarily modify signals
-;;   - Transform signals
+;; by signal data/content/etc.
-;;   - Filter    signals by arb conditions (incl. data/content)
 
-(t/set-middleware!
+(t/set-xfn!
   (fn [signal]
     (if (-> signal :data :skip-me?)
       nil ; Filter signal (don't handle)
-      (assoc signal :passed-through-middleware? true))))
+      (assoc signal :transformed? true))))
 
 (t/with-signal (t/event! ::my-id {:data {:skip-me? true}}))  ; => nil
 (t/with-signal (t/event! ::my-id {:data {:skip-me? false}})) ; => {...}
@@ -251,7 +250,7 @@ Detailed help is available without leaving your IDE:
 | :---------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------------------------------------- |
 | [`help:signal-creators`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-creators)                   | Creating signals                                                         |
 | [`help:signal-options`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-options)                     | Options when creating signals                                            |
-| [`help:signal-content`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content)                     | Signal content (map given to middleware/handlers)                        |
+| [`help:signal-content`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content)                     | Signal content (map given to transforms/handlers)                        |
 | [`help:filters`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:filters)                                   | Signal filtering and transformation                                      |
 | [`help:handlers`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handlers)                                 | Signal handler management                                                |
 | [`help:handler-dispatch-options`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handler-dispatch-options) | Signal handler dispatch options                                          |
@@ -314,7 +313,7 @@ You can also easily [write your own handlers](../../wiki/4-Handlers#writing-hand
 
 ## Community
 
-My plan for Telemere is to offer a **stable core of limited scope**, then to focus on making it as easy for the **community** to write additional stuff like handlers, middleware, and utils.
+My plan for Telemere is to offer a **stable core of limited scope**, then to focus on making it as easy for the **community** to write additional stuff like handlers, transforms, and utils.
 
 See [here](../../wiki/8-Community) for community resources.
 

examples.cljc

@@ -59,15 +59,14 @@
 ;; Set minimum level for `event!` signals for particular ns pattern
 (t/set-min-level! :event "taoensso.sente.*" :warn)
 
-;; Use middleware to:
+;; Use transforms (xfns) to filter and/or arbitrarily modify signals
-;;   - Transform signals
+;; by signal data/content/etc.
-;;   - Filter    signals by arb conditions (incl. data/content)
 
-(t/set-middleware!
+(t/set-xfn!
   (fn [signal]
     (if (-> signal :data :skip-me?)
       nil ; Filter signal (don't handle)
-      (assoc signal :passed-through-middleware? true))))
+      (assoc signal :transformed? true))))
 
 (t/with-signal (t/event! ::my-id {:data {:skip-me? true}}))  ; => nil
 (t/with-signal (t/event! ::my-id {:data {:skip-me? false}})) ; => {...}
@@ -333,16 +332,16 @@
 
 (t/with-signal
   (t/event! ::my-id
-    {:my-middleware-data "foo"
+    {:my-data-for-xfn     "foo"
-     :my-handler-data    "bar"}))
+     :my-data-for-handler "bar"}))
 
 ;; %>
 ;; {;; App-level kvs included inline (assoc'd to signal root)
-;;  :my-middleware-data "foo"
+;;  :my-data-for-xfn     "foo"
-;;  :my-handler-data    "bar"
+;;  :my-data-for-handler "bar"
 ;;  :kvs ; And also collected together under ":kvs" key
-;;  {:my-middleware-data "foo"
+;;  {:my-data-for-xfn     "foo"
-;;   :my-handler-data    "bar"}
+;;   :my-data-for-handler "bar"}
 ;;  ... }
 
 ;;;; Misc extra examples

main/resources/signal-docstrings/signal-content.txt

@@ -1,5 +1,5 @@
 Signals are maps with {:keys [inst id ns level data msg_ ...]}, though they
-can be modified by signal and/or handler middleware.
+can be modified by call and/or handler transform (xfns).
 
 Default signal keys:
 
@@ -33,7 +33,7 @@ Default signal keys:
 
 <kvs> ---------- Other arb app-level ?kvs given to signal creator. Typically NOT included
                  in handler output, so a great way to provide custom data/opts for use
-                 (only) by custom middleware/handlers.
+                 (only) by custom transforms/handlers.
 
 If anything is unclear, please ping me (@ptaoussanis) so that I can improve these docs!
 

main/resources/signal-docstrings/signal-options.txt

@@ -25,17 +25,18 @@ All options are available for all signal creator calls:
 `:coords` ------ Custom ?[line column] to override auto signal callsite info
 
 `:elidable?` --- Should signal be subject to compile-time elision? (Default: true)
+`:trace?` ------ Should tracing be enabled for `:run` form?
+
 `:sample-rate` - ?rate ∈ℝ[0,1] for signal sampling (0.75 => allow 75% of signals, nil => allow all)
 `:when` -------- Arb ?form; when present, form must return truthy to allow signal
 `:rate-limit` -- ?spec as given to `taoensso.telemere/rate-limiter`, see its docstring for details
 `:rate-limit-by` When present, rate limits will be enforced independently for each id (any Clojure value!)
-`:middleware` -- Optional (fn [signal]) => ?modified-signal to apply when signal is created, as per `with-middleware`
+`:xfn` --------- Optional       transform (fn [signal]) => ?modified-signal to apply when signal is created, as per `with-xfn`
-`:middleware+` - Optional (fn [signal]) => ?modified-signal to apply when signal is created, as per `with-middleware+`
+`:xfn+` -------- Optional extra transform (fn [signal]) => ?modified-signal to apply when signal is created, as per `with-xfn+`
-`:trace?` ------ Should tracing be enabled for `:run` form?
 
 <kvs> ---------- Other arb app-level ?kvs to incl. in signal. Typically NOT included in
                  handler output, so a great way to provide custom data/opts for use
-                 (only) by custom middleware/handlers.
+                 (only) by custom transforms/handlers.
 
 If anything is unclear, please ping me (@ptaoussanis) so that I can improve these docs!
 

main/src/taoensso/telemere.cljc

@@ -25,7 +25,7 @@
         ;; Via `sigs/def-api`
         without-filters with-kind-filter with-ns-filter with-id-filter
         with-min-level with-handler with-handler+
-        with-ctx with-ctx+ with-middleware with-middleware+]])))
+        with-ctx with-ctx+ with-xfn with-xfn+]])))
 
 (comment
   (remove-ns (symbol (str *ns*)))
@@ -50,7 +50,7 @@
   add-handler! remove-handler! stop-handlers!
 
   ^:dynamic *ctx* set-ctx! #?(:clj with-ctx) #?(:clj with-ctx+)
-  ^:dynamic *middleware* set-middleware! #?(:clj with-middleware) #?(:clj with-middleware+))
+  ^:dynamic *xfn* set-xfn! #?(:clj with-xfn) #?(:clj with-xfn+))
 
 (sigs/def-api
   {:sf-arity 4
@@ -73,7 +73,7 @@
   enc/chance
   enc/rate-limiter
   enc/newline
-  enc/comp-middleware
+  sigs/comp-xfn
   sigs/default-handler-dispatch-opts
   #?(:clj truss/keep-callsite)
 

main/src/taoensso/telemere/impl.cljc

@@ -18,7 +18,7 @@
 #?(:clj
    (enc/declare-remote
      ^:dynamic taoensso.telemere/*ctx*
-     ^:dynamic taoensso.telemere/*middleware*
+     ^:dynamic taoensso.telemere/*xfn*
      ^:dynamic taoensso.telemere/*uid-fn*
      ^:dynamic taoensso.telemere/*otel-tracer*))
 
@@ -393,7 +393,7 @@
        '(   [& opts-kvs]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id, ; Undocumented
-            elidable? coords #_inst #_uid #_middleware #_middleware+,
+            elidable? coords #_inst #_uid #_xfn #_xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             #_ctx #_ctx+ #_parent #_root #_trace?, #_do #_let #_data #_msg #_error #_run #_& #_kvs]}])
 
@@ -401,7 +401,7 @@
        '(   [& opts-kvs]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id, ; Undocumented
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error run & kvs]}])
 
@@ -410,7 +410,7 @@
          [level   msg]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error #_run & kvs]}
           msg])
@@ -421,7 +421,7 @@
          [id
           {:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error #_run & kvs]}])
 
@@ -430,7 +430,7 @@
          [id      run]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error run & kvs]}
           run])
@@ -440,7 +440,7 @@
          [level   run]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error run & kvs]}
           run])
@@ -450,7 +450,7 @@
          [id      error]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error #_run & kvs]}
           error])
@@ -460,7 +460,7 @@
          [id      run]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id, catch-val,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error #_run & kvs]}
           run])
@@ -470,7 +470,7 @@
          [opts-or-id]
          [{:as opts-map :keys
            [#_elide? #_allow? #_callsite-id,
-            elidable? coords inst uid middleware middleware+,
+            elidable? coords inst uid xfn xfn+,
             sample-rate kind ns id level when rate-limit rate-limit-by,
             ctx ctx+ parent root trace?, do let data msg error #_run & kvs]}])
 
@@ -618,15 +618,15 @@
                         `(taoensso.encore.signals/update-ctx taoensso.telemere/*ctx* ~ctx+)
                         (get opts :ctx                      `taoensso.telemere/*ctx*))
 
-                      middleware-form
+                      xfn-form
-                      (if-let [middleware+ (get opts :middleware+)]
+                      (if-let [xfn+ (get opts :xfn+)]
-                        `(taoensso.encore/comp-middleware taoensso.telemere/*middleware* ~middleware+)
+                        `(taoensso.encore.signals/comp-xfn taoensso.telemere/*xfn* ~xfn+)
-                        (get opts :middleware            `taoensso.telemere/*middleware*))
+                        (get opts :xfn                    `taoensso.telemere/*xfn*))
 
                       kvs-form
                       (not-empty
                         (dissoc opts
-                          :elidable? :coords :inst :uid :middleware :middleware+,
+                          :elidable? :coords :inst :uid :xfn :xfn+,
                           :sample-rate :ns :kind :id :level :filter :when #_:rate-limit #_:rate-limit-by,
                           :ctx :ctx+ :parent #_:trace?, :do :let :data :msg :error,
                           :run :run-form :run-val, :elide? :allow? #_:callsite-id :otel/context))
@@ -677,14 +677,14 @@
 
                   `(enc/bound-delay
                      ;; Delay (cache) shared by all handlers, incl. `:let` eval,
-                     ;; signal construction, middleware, etc. Throws caught by handler.
+                     ;; signal construction, transform (xfn), etc. Throws caught by handler.
                      ~do-form
                      (let [~@let-form ; Allow to throw, eval BEFORE data, msg, etc.
                            signal# ~signal-form]
 
                        ;; Final unwrapped signal value visible to users/handler-fns, allow to throw
-                       (if-let [sig-middleware# ~middleware-form]
+                       (if-let [xfn# ~xfn-form]
-                         (sig-middleware# signal#) ; Apply signal middleware, can throw
+                         (xfn# signal#) ; Apply call transform, can throw
                          (do   signal#)))))
 
                 ;; Trade-off: avoid double `run-form` expansion

main/src/taoensso/telemere/utils.cljc

@@ -1,5 +1,5 @@
 (ns taoensso.telemere.utils
-  "Misc utils useful for Telemere handlers, middleware, etc."
+  "Misc utils useful for Telemere handlers, transforms, etc."
   (:refer-clojure :exclude [newline])
   (:require
    [clojure.string          :as str]

main/test/taoensso/telemere_tests.cljc

@@ -250,35 +250,35 @@
                  (with-sig (sig! {:level :info, :ctx+ {:baz :qux}})))]
         (is (sm? sv {:ctx {:foo :bar, :baz :qux}}) "`*ctx*` can be updated via call opt"))])
 
-   (testing "Middleware"
+   (testing "Transforms"
-     [(testing "Dynamic middleware (`*middleware*`)"
+     [(testing "Dynamic transforms (`*xfn*`)"
-        [(is (sm? (tel/with-middleware nil               (with-sig (sig! {:level :info                 })))               {:level :info                 }) "nil middleware ~ identity")
+        [(is (sm? (tel/with-xfn nil               (with-sig (sig! {:level :info                 })))        {:level :info                 }) "nil xfn ~ identity")
-         (is (sm? (tel/with-middleware identity          (with-sig (sig! {:level :info                 })))               {:level :info                 }) "nil middleware ~ identity")
+         (is (sm? (tel/with-xfn identity          (with-sig (sig! {:level :info                 })))        {:level :info                 }) "nil xfn ~ identity")
-         (is (sm? (tel/with-middleware #(assoc % :foo 1) (with-sig (sig! {:level :info                 })))               {:level :info, :foo 1         }))
+         (is (sm? (tel/with-xfn #(assoc % :foo 1) (with-sig (sig! {:level :info                 })))        {:level :info, :foo 1         }))
-         (is (sm? (tel/with-middleware #(assoc % :foo 1) (with-sig (sig! {:level :info, :middleware #(assoc % :foo 2)}))) {:level :info, :foo 2         }) "call > dynamic")
+         (is (sm? (tel/with-xfn #(assoc % :foo 1) (with-sig (sig! {:level :info, :xfn #(assoc % :foo 2)}))) {:level :info, :foo 2         }) "call > dynamic")
-         (is (sm? (tel/with-middleware #(assoc % :foo 1) (with-sig (sig! {:level :info, :middleware nil})))               {:level :info, :foo :submap/nx}) "call > dynamic")
+         (is (sm? (tel/with-xfn #(assoc % :foo 1) (with-sig (sig! {:level :info, :xfn nil})))               {:level :info, :foo :submap/nx}) "call > dynamic")
-         (is (=   (tel/with-middleware #(do nil)         (with-sig (sig! {:level :info                 })))               nil)                             "return nil => suppress")
+         (is (=   (tel/with-xfn #(do nil)         (with-sig (sig! {:level :info          })))               nil)                             "return nil => suppress")
-         (is (sm? (tel/with-middleware #(do nil)         (with-sig (sig! {:level :info, :middleware nil})))               {:level :info})                  "call > dynamic")])
+         (is (sm? (tel/with-xfn #(do nil)         (with-sig (sig! {:level :info, :xfn nil})))               {:level :info})                  "call > dynamic")])
 
-      (testing "Call middleware"
+      (testing "Call transforms"
         (let [c (enc/counter)
-              {rv1 :value, [sv1] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c)))}))
+              {rv1 :value, [sv1] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c)))}))
-              {rv2 :value, [sv2] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c))), :allow? false}))
+              {rv2 :value, [sv2] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c))), :allow? false}))
-              {rv3 :value, [sv3] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c)))}))
+              {rv3 :value, [sv3] :signals} (with-sigs :raw nil (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c)))}))
-              {rv4 :value, [sv4] :signals} (with-sigs :raw nil (sig! {:level :info,           :middleware (fn [_] "signal-value")}))
+              {rv4 :value, [sv4] :signals} (with-sigs :raw nil (sig! {:level :info,           :xfn (fn [_] "signal-value")}))
-              {rv5 :value, [sv5] :signals} (with-sigs :raw nil (sig! {:level :info,           :middleware (fn [_] nil)}))]
+              {rv5 :value, [sv5] :signals} (with-sigs :raw nil (sig! {:level :info,           :xfn (fn [_] nil)}))]
 
           [(is (= rv1 0))    (is (sm? sv1 {:m1 1 :m2 2}))
            (is (= rv2 3))    (is (nil?    sv2))
            (is (= rv3 4))    (is (sm? sv3 {:m1 5 :m2 6}))
            (is (= rv4 true)) (is (=       sv4 "signal-value"))
            (is (= rv5 true)) (is (nil?    sv5))
-           (is (= @c  7)     "3x run + 4x middleware")]))
+           (is (= @c  7)     "3x run + 4x xfn")]))
 
-      (testing "Mixed middleware"
+      (testing "Mixed transforms"
         [(let [sv
-               (binding [tel/*middleware* #(assoc % :foo true)]
+               (binding [tel/*xfn* #(assoc % :foo true)]
-                 (with-sig (sig! {:level :info, :middleware+ #(assoc % :bar true)})))]
+                 (with-sig (sig! {:level :info, :xfn+ #(assoc % :bar true)})))]
            (is (sm? sv {:foo true, :bar true})))])])
 
    #?(:clj
@@ -293,35 +293,35 @@
 
 (deftest _handlers
   ;; Basic handler tests are in Encore
-  [(testing "Handler middleware"
+  [(testing "Handler transforms"
      (let [c      (enc/counter)
            sv-h1_ (atom nil)
            sv-h2_ (atom nil)
-           wh1    (sigs/wrap-handler :hid1 (fn [sv] (reset! sv-h1_ sv)) nil {:async nil, :middleware (tel/comp-middleware #(assoc % :hm1 (c)) #(assoc % :hm2 (c)))})
+           wh1    (sigs/wrap-handler :hid1 (fn [sv] (reset! sv-h1_ sv)) nil {:async nil, :xfn (tel/comp-xfn #(assoc % :hm1 (c)) #(assoc % :hm2 (c)))})
-           wh2    (sigs/wrap-handler :hid2 (fn [sv] (reset! sv-h2_ sv)) nil {:async nil, :middleware (tel/comp-middleware #(assoc % :hm1 (c)) #(assoc % :hm2 (c)))})]
+           wh2    (sigs/wrap-handler :hid2 (fn [sv] (reset! sv-h2_ sv)) nil {:async nil, :xfn (tel/comp-xfn #(assoc % :hm1 (c)) #(assoc % :hm2 (c)))})]
 
-       ;; Note that call middleware output is cached and shared across all handlers
+       ;; Note that call xfn output is cached and shared across all handlers
        (binding [impl/*sig-handlers* [wh1 wh2]]
-         (let [;; 1x run + 4x handler middleware + 2x call middleware = 7x
+         (let [;; 1x run + 4x handler xfn + 2x call xfn = 7x
-               rv1    (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c)))})
+               rv1    (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c)))})
                sv1-h1 @sv-h1_
                sv1-h2 @sv-h2_
                c1     @c
 
                ;; 1x run
-               rv2    (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c))), :allow? false})
+               rv2    (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c))), :allow? false})
                sv2-h1 @sv-h1_
                sv2-h2 @sv-h2_
                c2     @c ; 8
 
-               ;; 1x run + 4x handler middleware + 2x call middleware = 7x
+               ;; 1x run + 4x handler xfn + 2x call xfn = 7x
-               rv3    (sig! {:level :info, :run (c), :middleware (tel/comp-middleware #(assoc % :m1 (c)) #(assoc % :m2 (c)))})
+               rv3    (sig! {:level :info, :run (c), :xfn (tel/comp-xfn #(assoc % :m1 (c)) #(assoc % :m2 (c)))})
                sv3-h1 @sv-h1_
                sv3-h2 @sv-h2_
                c3     @c ; 15
 
-               ;; 4x handler middleware
+               ;; 4x handler xfn
-               rv4    (sig! {:level :info, :middleware (fn [_] {:my-sig-val? true})})
+               rv4    (sig! {:level :info, :xfn (fn [_] {:my-sig-val? true})})
                sv4-h1 @sv-h1_
                sv4-h2 @sv-h2_
                c4     @c]
@@ -330,10 +330,10 @@
             (is (= rv2 7))    (is (sm? sv2-h1 {:m1 1, :m2 2,      :hm1 3,  :hm2 4}))  (is (sm? sv2-h2 {:m1 1, :m2 2,      :hm1 5,  :hm2 6}))
             (is (= rv3 8))    (is (sm? sv3-h1 {:m1 9, :m2 10,     :hm1 11, :hm2 12})) (is (sm? sv3-h2 {:m1 9, :m2 10,     :hm1 13, :hm2 14}))
             (is (= rv4 true)) (is (sm? sv4-h1 {:my-sig-val? true, :hm1 15, :hm2 16})) (is (sm? sv4-h2 {:my-sig-val? true, :hm1 17, :hm2 18}))
-            (is (= c1  7)     "1x run +  4x handler middleware + 2x call middleware")
+            (is (= c1  7)     "1x run +  4x handler xfn + 2x call xfn")
-            (is (= c2  8)     "2x run +  4x handler middleware + 2x call middleware")
+            (is (= c2  8)     "2x run +  4x handler xfn + 2x call xfn")
-            (is (= c3  15)    "3x run +  8x handler middleware + 4x call middleware")
+            (is (= c3  15)    "3x run +  8x handler xfn + 4x call xfn")
-            (is (= c4  19)    "3x run + 12x handler middleware + 4x call middleware")]))))
+            (is (= c4  19)    "3x run + 12x handler xfn + 4x call xfn")]))))
 
    (testing "Handler binding conveyance"
      (let [a (atom nil)
@@ -379,7 +379,7 @@
                  (test1 64 {:async {:mode :dropping, :buffer-size 64}})
                  (test1 64 {:async {:mode :sliding,  :buffer-size 64}})]))))))])
 
-(def ^:dynamic *throwing-handler-middleware?* false)
+(def ^:dynamic *throwing-handler-xfn?* false)
 
 (deftest _throwing
   (let [sv_    (atom :nx)
@@ -393,7 +393,7 @@
     (tel/with-handler :hid1
       (fn [sv] (force (:data sv)) (reset! sv_ sv))
       {:async nil, :error-fn (fn [x] (reset! error_ x)), :rl-error nil,
-       :middleware (fn [sv] (if *throwing-handler-middleware?* (ex1!) sv))}
+       :xfn (fn [sv] (if *throwing-handler-xfn?* (ex1!) sv))}
 
       [(is (->> (sig! {:level :info, :when  (ex1!)}) (throws? :ex-info "Ex1")) "`~filterable-expansion/allow` throws at call")
        (is (->> (sig! {:level :info, :inst  (ex1!)}) (throws? :ex-info "Ex1")) "`~inst-form`                  throws at call")
@@ -409,15 +409,15 @@
              (is (= @sv_ :nx))
              (is (sm? @error_ {:handler-id :hid1, :error ex1}))])
 
-          (testing "Throwing call middleware"
+          (testing "Throwing call transform"
             (reset-state!)
-            [(is (true? (sig! {:level :info, :middleware (fn [_] (ex1!))})))
+            [(is (true? (sig! {:level :info, :xfn (fn [_] (ex1!))})))
              (is (= @sv_ :nx))
              (is (sm? @error_ {:handler-id :hid1, :error ex1}))])
 
-          (testing "Throwing handler middleware"
+          (testing "Throwing handler transform"
             (reset-state!)
-            (binding [*throwing-handler-middleware?* true]
+            (binding [*throwing-handler-xfn?* true]
               [(is (true? (sig! {:level :info})))
                (is (= @sv_ :nx))
                (is (sm? @error_ {:handler-id :hid1, :error ex1}))]))

wiki/1-Getting-started.md

@@ -175,10 +175,10 @@ A signal will be provided to a handler iff ALL of the following are true:
 	- a. Compile time: not applicable
 	- b. Runtime: sample rate, kind, ns, id, level, when fn, rate limit
 	  
-- 3. **Call middleware** `(fn [signal]) => ?modified-signal` returns non-nil
+- 3. **Call transform** `(fn [signal]) => ?modified-signal` returns non-nil
-- 4. **Handler middleware** `(fn [signal]) => ?modified-signal` returns non-nil
+- 4. **Handler transform** `(fn [signal]) => ?modified-signal` returns non-nil
 
-> Middleware provides a flexible way to modify and/or filter signals by arbitrary signal data/content conditions (return nil to skip).
+> Transform fns provides a flexible way to modify and/or filter signals by arbitrary signal data/content conditions (return nil to skip handling).
 
 Quick examples of some basic filtering:
 
@@ -206,7 +206,7 @@ Telemere includes extensive internal help docstrings:
 | :---------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------------------------------------- |
 | [`help:signal-creators`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-creators)                   | Creating signals                                                         |
 | [`help:signal-options`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-options)                     | Options when creating signals                                            |
-| [`help:signal-content`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content)                     | Signal content (map given to middleware/handlers)                        |
+| [`help:signal-content`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content)                     | Signal content (map given to transforms/handlers)                        |
 | [`help:filters`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:filters)                                   | Signal filtering and transformation                                      |
 | [`help:handlers`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handlers)                                 | Signal handler management                                                |
 | [`help:handler-dispatch-options`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handler-dispatch-options) | Signal handler dispatch options                                          |

wiki/2-Architecture.md

@@ -16,4 +16,4 @@ This flow is visualized below:
 <img src="https://raw.githubusercontent.com/taoensso/telemere/master/imgs/signal-flow.svg" alt="Telemere signal flowchart" width="640"/>
 
 - `A/sync queue` semantics are specified via [handler dispatch options](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handler-dispatch-options).
-- The shared **call middleware cache** is super useful when doing signal transformations that are expensive and/or involve side effects (like syncing with another service/db to get a unique tx id, etc.).
+- The shared **call transform** cache is super useful when doing signal transformations that are expensive and/or involve side effects (like syncing with another service/db to get a unique tx id, etc.).

wiki/3-Config.md

@@ -12,10 +12,10 @@ A signal will be provided to a handler iff ALL of the following are true:
 	- a. Compile time: not applicable
 	- b. Runtime: sample rate, kind, ns, id, level, when fn, rate limit
 	  
-- 3. **Call middleware** `(fn [signal]) => ?modified-signal` returns non-nil
+- 3. **Call transform** `(fn [signal]) => ?modified-signal` returns non-nil
-- 4. **Handler middleware** `(fn [signal]) => ?modified-signal` returns non-nil
+- 4. **Handler transform** `(fn [signal]) => ?modified-signal` returns non-nil
 
-> Middleware provides a flexible way to modify and/or filter signals by arbitrary signal data/content conditions (return nil to skip).
+> Transform fns provides a flexible way to modify and/or filter signals by arbitrary signal data/content conditions (return nil to skip handling).
 
 See [`help:filters`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:filters) for more about filtering.
 

wiki/4-Handlers.md

@@ -48,11 +48,11 @@ There's two kinds of config relevant to all signal handlers:
 
 ## Dispatch opts
 
-Handler dispatch opts includes dispatch priority (determines order in which handlers are called), handler filtering, handler middleware, a/sync queue semantics, back-pressure opts, etc.
+Handler dispatch opts includes dispatch priority (determines order in which handlers are called), handler filtering, handler transform, a/sync queue semantics, back-pressure opts, etc.
 
 See [`help:handler-dispatch-options`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:handler-dispatch-options) for full info, and [`default-handler-dispatch-opts`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#default-handler-dispatch-opts) for defaults.
 
-Note that handler middleware in particular is an easily overlooked but powerful feature, allowing you to arbitrarily transform and/or filter every [signal map](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content) before it is given to each handler.
+Note that the handler transform is an easily overlooked but powerful feature, allowing you to arbitrarily modify and/or filter every [signal map](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#help:signal-content) before it is given to each handler.
 
 ## Handler-specific opts
 
@@ -120,27 +120,27 @@ Note that when writing JSON with Clojure, you *must* provide an appropriate `pr-
 
 ### Handler-specific per-signal kvs
 
-Telemere includes a handy mechanism for including arbitrary app-level data/opts in individual signals for use by custom middleware and/or handlers.
+Telemere includes a handy mechanism for including arbitrary app-level data/opts in individual signals for use by custom transforms and/or handlers.
 
 Any *non-standard* (app-level) keys you include in your signal constructor opts will automatically be included in created signals, e.g.:
 
 ```clojure
 (t/with-signal
   (t/event! ::my-id
-    {:my-middleware-data "foo"
+    {:my-data-for-xfn     "foo"
-     :my-handler-data    "bar"}))
+     :my-data-for-handler "bar"}))
 
 ;; %>
 ;; {;; App-level kvs included inline (assoc'd to signal root)
-;;  :my-middleware-data "foo"
+;;  :my-data-for-xfn     "foo"
-;;  :my-handler-data    "bar"
+;;  :my-data-for-handler "bar"
 ;;  :kvs ; And also collected together under ":kvs" key
-;;  {:my-middleware-data "foo"
+;;  {:my-data-for-xfn     "foo"
-;;   :my-handler-data    "bar"}
+;;   :my-data-for-handler "bar"}
 ;;  ... }
 ```
 
-These app-level data/opts are typically NOT included by default in handler output, making them a great way to convey data/opts to custom middleware/handlers.
+These app-level data/opts are typically NOT included by default in handler output, making them a great way to convey data/opts to custom transforms/handlers.
 
 # Managing handlers
 

wiki/7-Tips.md

@@ -80,9 +80,9 @@ Consider the [differences](https://www.youtube.com/watch?v=oyLBGkS5ICk) between
   
   This way you can see all your ids in one place, and precise info on when ids were added/removed/changed.
   
-- Use **signal call middleware** to your advantage.
+- Use **signal call transforms** to your advantage.
   
-  The result of call middleware is cached and *shared between all handlers* making it an efficient place to transform signals. For this reason - prefer signal middleware to handler middleware when possible/convenient.
+  The result of call-side signal transforms is cached and *shared between all handlers* making it an efficient place to modify signals going to >1 handler.
   
 - Signal and handler **sampling is multiplicative**.
   
@@ -94,12 +94,12 @@ Consider the [differences](https://www.youtube.com/watch?v=oyLBGkS5ICk) between
   
   So for `n` randomly sampled signals matching some criteria, you'd have seen an estimated `Σ(1.0/sample-rate_i)` such signals _without_ sampling, etc.
   
-- Middleware can return any type, but it's best to return only `nil` or a map. This ensures maximum compatibility with community middleware, handlers, and tools.
+- Transforms can technically return any type, but it's best to return only `nil` or a map. This ensures maximum compatibility with community transforms, handlers, and tools.
   
-- Middleware can be used to **filter signals** by returning `nil`.
+- Transforms can be used to **filter signals** by returning `nil`.
-- Middleware can be used to **split signals**:
+- Transforms can be used to **split signals**:
   
-  Your middleware can *call signal creators* like any other code. Return `nil` after to filter the source signal. Just be aware that new signals will re-enter your handler queue/s as would any other signal - and so may be subject to handling delay and normal handler queue back-pressure.
+  Your transforms can *call signal creators* like any other code. Return `nil` after to filter the source signal. Just be aware that new signals will re-enter your handler queue/s as would any other signal - and so may be subject to handling delay and normal handler queue back-pressure.
   
   See also the [`dispatch-signal!`](https://cljdoc.org/d/com.taoensso/telemere/CURRENT/api/taoensso.telemere#dispatch-signal!) util.
   
@@ -122,7 +122,7 @@ Consider the [differences](https://www.youtube.com/watch?v=oyLBGkS5ICk) between
   
   Note that all app-level kvs will *also* be available *together* under the signal's `:kvs` key.
   
-  App-level kvs are typically *not* included in handler output, so are a great way of providing custom data/opts for use (only) by custom middleware or handlers.
+  App-level kvs are typically *not* included in handler output, so are a great way of providing custom data/opts for use (only) by custom transforms or handlers.
   
 - Signal `kind` can be useful in advanced cases.
   

wiki/8-Community.md

@@ -1,4 +1,4 @@
-My plan for Telemere is to offer a **stable core of limited scope**, then to focus on making it as easy for the **community** to write additional stuff like handlers, middleware, and utils.
+My plan for Telemere is to offer a **stable core of limited scope**, then to focus on making it as easy for the **community** to write additional stuff like handlers, transforms, and utils.
 
 **PRs very welcome** to add links to this page!
 
@@ -20,7 +20,7 @@ Includes videos, tutorials, demo projects, etc.
 
 # Handlers and tools
 
-Includes libraries or examples for handlers (see [Writing handlers](./4-Handlers#writing-handlers)), middleware, handler utils (e.g. formatters), tools for analyzing signals, etc. [PRs](../wiki#contributions-welcome) welcome for additions!
+Includes libraries or examples for handlers (see [Writing handlers](./4-Handlers#writing-handlers)), transforms, handler utils (e.g. formatters), tools for analyzing signals, etc. [PRs](../wiki#contributions-welcome) welcome for additions!
 
 | Type | Description                                                   |
 | ---- | :------------------------------------------------------------ |