impl attrs detection in binding

src/dev/onionpancakes/chassis/compiler.clj

@@ -2,6 +2,10 @@
   (:refer-clojure :exclude [compile])
   (:require [dev.onionpancakes.chassis.core :as c]))
 
+;; Examine compiler binding expressions for attrs maps.
+(defprotocol AttributesCompilerExpr
+  (attrs-compiler-expr? [this] "Returns true if clojure.lang.Compiler$Expr is attrs."))
+
 (defprotocol CompilableForm
   (attrs? [this] "Returns true if form is attrs. Returns false if it might be attrs.")
   (not-attrs? [this] "Returns true if form is not attrs. Returns false if it might be attrs.")
@@ -89,6 +93,26 @@
       (attrs-type? (resolve tag-sym)))
     false))
 
+(defn attrs-binding?
+  [^clojure.lang.Compiler$LocalBinding b]
+  (attrs-compiler-expr? (.-init b)))
+
+(extend-protocol AttributesCompilerExpr
+  clojure.lang.Compiler$NilExpr
+  (attrs-compiler-expr? [_] true)
+  clojure.lang.Compiler$EmptyExpr
+  (attrs-compiler-expr? [this]
+    (attrs-type? (.getJavaClass this)))
+  clojure.lang.Compiler$ConstantExpr
+  (attrs-compiler-expr? [this]
+    ;; Class not public for some reason, can't call method.
+    #_(attrs-type? (.getJavaClass this))
+    false)
+  clojure.lang.Compiler$MapExpr
+  (attrs-compiler-expr? [this] true)
+  Object
+  (attrs-compiler-expr? [_] false))
+
 (extend-protocol CompilableForm
   dev.onionpancakes.chassis.core.OpeningTag
   (attrs? [this] false)
@@ -160,7 +184,8 @@
   (attrs? [this]
     (or (attrs-type-hinted? this)
         (if-some [entry (find *env* this)]
-          (attrs-type-hinted? (key entry))
+          (or (attrs-type-hinted? (key entry))
+              (attrs-binding? (val entry)))
           false)))
   (not-attrs? [this] false)
   (constant? [_] false)
@@ -201,7 +226,6 @@
 
 (defn attrs-present-evaluated?
   [elem]
-  {:pre [(attrs-present? elem)]}
   (evaluated? (nth elem 1)))
 
 (defn attrs-absent?

test/dev/onionpancakes/chassis/tests/test_compiler.clj

@@ -114,15 +114,26 @@
   (defmethod c/resolve-alias ::ReflectiveAttrsAlias
     [_ _ ^java.util.Map attrs content]
     (cc/compile [:div.reflective-alias-attrs attrs content]))
+  ;; Type hinted invocation
+  (cc/compile [:div ^java.util.Map (:foo {:foo {}}) "foobar"])
   ;; Vetted attrs fns
   (cc/compile [:div (assoc {} :foo "bar") "foobar"])
   (cc/compile [:div (assoc-in {} [:foo :bar] "bar") "foobar"])
   (cc/compile [:div (merge {} {:foo "bar"}) "foobar"])
   (cc/compile [:div (select-keys {} [:foo]) "foobar"])
   (cc/compile [:div (update-keys {} identity) "foobar"])
   (cc/compile [:div (update-vals {} identity) "foobar"])
-  ;; Type hinted invocation
-  (cc/compile [:div ^java.util.Map (:foo {:foo {}}) "foobar"])
+  ;; LocalBinded attrs literals
+  (let [attrs nil]
+    (cc/compile [:div attrs "foobar"]))
+  (let [attrs {}]
+    (cc/compile [:div attrs "foobar"]))
+  ;; ConstantExpr not public, can't determine constant attrs case.
+  #_
+  (let [attrs {:foo "bar"}]
+    (cc/compile [:div attrs "foobar"]))
+  (let [attrs {:foo (identity "bar")}]
+    (cc/compile [:div attrs "foobar"]))
   )
 
 (remove-tap count-ambig-attrs)