Pessimize match-conditional-to-when slightly

default-recommendations/match-shortcuts-test.rkt

@@ -230,46 +230,69 @@ no-change-test: "root-level and pattern not removed when not matching on a simpl
 ------------------------------
 
 
-test: "match patterns with if conditionals can be simplified using #:when clauses"
+test: "match patterns with long if conditionals can be simplified using #:when clauses"
 ------------------------------
 (define (f pt)
   (match pt
     [(list x y)
      (if (> x y)
-         (list y x)
+         (list y x 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo)
          pt)]
     [(list) '()]))
 ==============================
 (define (f pt)
   (match pt
     [(list x y)
      #:when (> x y)
-     (list y x)]
+     (list y x 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo)]
     [(list x y) pt]
     [(list) '()]))
 ------------------------------
 
 
-test: "match patterns with cond conditionals can be simplified using #:when clauses"
+no-change-test: "match patterns with short if conditionals won't be simplified using #:when clauses"
+------------------------------
+(define (f pt)
+  (match pt
+    [(list x y)
+     (if (> x y)
+         (list y x)
+         pt)]
+    [(list) '()]))
+------------------------------
+
+
+test: "match patterns with long cond conditionals can be simplified using #:when clauses"
 ------------------------------
 (define (f pt)
   (match pt
     [(list x y)
      (cond
-       [(> x y) (list y x)]
+       [(> x y) (list y x 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo)]
        [else pt])]
     [(list) '()]))
 ==============================
 (define (f pt)
   (match pt
     [(list x y)
      #:when (> x y)
-     (list y x)]
+     (list y x 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo 'foo)]
     [(list x y) pt]
     [(list) '()]))
 ------------------------------
 
 
+no-change-test: "match patterns with short cond conditionals won't be simplified using #:when clauses"
+------------------------------
+(define (f pt)
+  (match pt
+    [(list x y)
+     (cond
+       [(> x y) (list y x)]
+       [else pt])]
+    [(list) '()]))
+------------------------------
+
 test: "match patterns with multi-body cond conditionals can be simplified using #:when clauses"
 ------------------------------
 (define (f pt)

default-recommendations/match-shortcuts.rkt

@@ -208,6 +208,13 @@
   #:when (oneline-syntax? (attribute pattern))
   #:when (<= (syntax-span (attribute pattern)) 60)
 
+  ; Conversely, a conditional with short body expressions isn't worth duplicating the condition
+  ; expression, so we only attempt to refactor conditionals whose body expressions aren't short.
+  #:when (or (> (length (attribute conditional.then-expr)) 1)
+             (> (length (attribute conditional.else-expr)) 1)
+             (>= (syntax-span (first (attribute conditional.then-expr))) 60)
+             (>= (syntax-span (first (attribute conditional.else-expr))) 60))
+
   (match subject
     clause-before ...
     (~@ . (~splicing-replacement ([pattern #:when conditional.condition conditional.then-expr ...]