Rewrite send chains to send+

Closes #390.

default-recommendations.rkt

@@ -6,6 +6,7 @@
 
 (provide
  (all-from-out resyntax/default-recommendations/boolean-shortcuts
+               resyntax/default-recommendations/class-shortcuts
                resyntax/default-recommendations/comparison-shortcuts
                resyntax/default-recommendations/conditional-shortcuts
                resyntax/default-recommendations/console-io-suggestions
@@ -37,6 +38,7 @@
 (require rebellion/private/static-name
          resyntax/base
          resyntax/default-recommendations/boolean-shortcuts
+         resyntax/default-recommendations/class-shortcuts
          resyntax/default-recommendations/comparison-shortcuts
          resyntax/default-recommendations/conditional-shortcuts
          resyntax/default-recommendations/console-io-suggestions
@@ -68,6 +70,7 @@
 
 (define-refactoring-suite default-recommendations
   #:suites (boolean-shortcuts
+            class-shortcuts
             comparison-shortcuts
             conditional-shortcuts
             console-io-suggestions

default-recommendations/class-shortcuts-test.rkt

@@ -0,0 +1,29 @@
+#lang resyntax/test
+
+
+require: resyntax/default-recommendations class-shortcuts
+
+
+header:
+--------------------
+#lang racket/base
+(require racket/class)
+--------------------
+
+
+test: "nested send expressions refactorable to flat send+ expression"
+--------------------
+(define (f obj x y z)
+  (send (send (send obj m1 x) m2 y) m3 z))
+--------------------
+--------------------
+(define (f obj x y z)
+  (send+ obj (m1 x) (m2 y) (m3 z)))
+--------------------
+
+
+test: "two-method nested send expression not refactorable to send+"
+--------------------
+(define (f obj x y)
+  (send (send obj m1 x) m2 y))
+--------------------

default-recommendations/class-shortcuts.rkt

@@ -0,0 +1,46 @@
+#lang racket/base
+
+
+(require racket/contract/base)
+
+
+(provide
+ (contract-out
+  [class-shortcuts refactoring-suite?]))
+
+
+(require racket/class
+         resyntax/base
+         syntax/parse)
+
+
+;@----------------------------------------------------------------------------------------------------
+
+
+(define-syntax-class manual-method-chain
+  #:attributes (initial-object [method 1] [arg 2])
+  #:literals (send)
+
+  (pattern (send inner-chain:manual-method-chain last-method:id last-method-arg ...)
+    #:attr initial-object (attribute inner-chain.initial-object)
+    #:attr [method 1] (append (attribute inner-chain.method) (list #'last-method))
+    #:attr [arg 2] (append (attribute inner-chain.arg) (list (attribute last-method-arg))))
+
+  (pattern (send (~and initial-object (~not _:manual-method-chain))
+                 first-method:id
+                 first-method-arg ...)
+    #:attr [method 1] (list #'first-method)
+    #:attr [arg 2] (list (attribute first-method-arg))))
+
+
+(define-refactoring-rule send-chain-to-send+
+  #:description
+  "This method chain made of nested `send` expressions can be written more clearly as a `send+`\
+ expression."
+  chain:manual-method-chain
+  #:when (>= (length (attribute chain.method)) 3)
+  (send+ chain.initial-object (chain.method chain.arg ...) ...))
+
+
+(define-refactoring-suite class-shortcuts
+  #:rules (send-chain-to-send+))