Experiment to improve performance

src/clj_commons/ansi.clj

@@ -172,26 +172,25 @@
           {:keys [font width pad] :as span-decl} (extract-span-decl first-element)]
       (if width
         (let [;; Transform this span and everything below it into easily managed span vectors, starting
-              ;; with a reduced version of the span decl.
+              ;; with a version of this span decl.
               span-decl' (dissoc span-decl :width :pad)
               *length (volatile! 0)
               inputs' (into [span-decl'] (normalize-markup inputs *length))
               spaces (padding (- width @*length))
-              ;; Added the padding in the desired position; this ensures that the logic that generates
+              ;; Add the padding in the desired position; this ensures that the logic that generates
               ;; ANSI escape codes occurs correctly, with the added spaces getting the font for this span.
               padded (if (= :right pad)
                        (conj inputs' spaces)
                        ;; An "insert-at" for vectors would be nice
                        (into [(first inputs') spaces] (next inputs')))]
           (recur state padded))
         ;; Normal (no width tracking)
-        (let [{:keys [current]} state
-              state' (reduce collect-markup
-                             (-> state
-                                 (update :current update-font-data-from-font-def font)
-                                 (update :stack conj current))
-                             inputs)]
-          (-> state'
+        (let [{:keys [current]} state]
+          (-> (reduce collect-markup
+                      (-> state
+                          (update :current update-font-data-from-font-def font)
+                          (update :stack conj current))
+                      inputs)
               (assoc :current current
                      :tracking-width? false)
               (update :stack pop)))))
@@ -226,6 +225,7 @@
   Nested vectors represent _spans_, a sequence of values with a specific visual representation.
   The first element in a span vector declares the visual properties of the span: the color (including
   other characteristics such as bold or underline), and the width and padding (described later).
+  Spans may be nested.
 
   The declaration is usually a keyword, to define just the font.
   The font def contains one or more terms, separated by periods.
@@ -248,7 +248,7 @@
   => ...
   ```
 
-  The order of the terms does not matter. Behavior for conflicting terms (`:blue.green.black`)
+  The order of the terms does not matter. Behavior for conflicting terms (e.g., `:blue.green.black`)
   is not defined.
 
 
@@ -263,8 +263,8 @@
 
   The core colors are `black`, `red`, `green`, `yellow`, `blue`, `magenta`, `cyan`, and `white`.
 
-  When [[*color-enabled*]] is false, then any font defs are validated, then ignored (no ANSI codes
-  will be included).
+  When [[*color-enabled*]] is false, then any font defs are validated, but otherwise ignored (no ANSI codes
+  will be included in the composed string).
 
   The span's font declaration may also be a map with the following keys:
 
@@ -292,7 +292,9 @@
       [{:font :red
         :width 20} message]
 
-  This will output the value of `message` in red text, padded with spaces on the left to be 20 characters."
+  This will output the value of `message` in red text, padded with spaces on the left to be 20 characters.
+
+  compose does not truncate a span to a width, it only pads if the span in too short."
   {:added "1.4.0"}
   [& inputs]
   (let [initial-font {:foreground "39"

src/clj_commons/format/exceptions.clj

@@ -560,10 +560,7 @@
     "nil"
     x))
 
-(defn format-exception*
-  "Contains the main logic for [[format-exception]], which simply expands
-  the exception (via [[analyze-exception]]) before invoking this function."
-  {:added "0.1.21"}
+(defn- render-exception
   [exception-stack options]
   (let [{show-properties? :properties
          :or {show-properties? true}} options
@@ -601,7 +598,7 @@
                      (map exception-f (?reverse modern? exception-stack))
                      "\n")
         root-stack-trace (-> exception-stack last :stack-trace)]
-    (compose
+    (list
       (when *traditional*
         exceptions)
 
@@ -611,6 +608,14 @@
       (when modern?
         exceptions))))
 
+(defn format-exception*
+  "Contains the main logic for [[format-exception]], which simply expands
+  the exception (via [[analyze-exception]]) before invoking this function."
+  {:added "0.1.21"}
+  [exception-stack options]
+  (compose
+    (render-exception exception-stack options)))
+
 (defn format-exception
   "Formats an exception, returning a single large string.
 

test/demo.clj

@@ -104,6 +104,16 @@
   (let [e (make-ex-info)]
     (c/bench (e/format-exception e)))
 
+
+  ;; 27 Jun 2023 -  767 µs                  - Clojure 1.11.1, Corretto 17.0.7, M1
+  (let [e (make-ex-info)
+        composed (#'e/render-exception (e/analyze-exception e nil) nil)]
+    (c/bench (compose composed)))
+
+  ;; 27 Jun 2023 - 182 µs                   - Clojure 1.11.1, Corretto 17.0.7, M1
+  (let [e (make-ex-info)]
+    (c/bench (#'e/render-exception (e/analyze-exception e nil) nil)))
+
   ;; 11 Feb 2016 - 213 µs (4 µs std dev) - Clojure 1.8
   ;; 28 Sep 2018 - 237 µs (8 µs std dev) - Clojure 1.9