d8

2017/d8/main.rkt

@@ -0,0 +1,30 @@
+#lang reader "../aoc-lang.rkt"
+(provide (rename-out [#%mb #%module-begin]))
+
+(define-macro (#%mb (STARS) (TOK ...) ...)
+  #`(#%module-begin
+     (inst TOK ...) ...
+     (if (eq? 'STARS '★) (max-arg vals) max-seen)))
+
+(define vals (make-hasheq))
+(define (get-val key) (hash-ref! vals key 0))
+(define (max-arg vals) (argmax cdr (hash->list vals)))
+(define max-seen 0)
+(define (set-val! key updater)
+  (hash-update! vals key updater 0)
+  (set! max-seen (max max-seen (cdr (max-arg vals)))))
+
+(provide >= <= < > ==)
+(define-macro-cases cmp
+  [(_ ==) #'=]
+  [(_ !=) #'(negate =)]
+  [(_ OTHER) #'OTHER])
+
+(define-macro-cases updater
+  [(_ dec) #'-]
+  [(_ inc) #'+])
+
+(provide if)
+(define-macro (inst TARGET UPDATE-OP UPDATE-VAL if SRC CMP VAL)
+  #'(when ((cmp CMP) (get-val 'SRC) VAL)
+      (set-val! 'TARGET (λ (val) ((updater UPDATE-OP) val UPDATE-VAL)))))

2017/d8/test1.rkt

@@ -0,0 +1,5 @@
+#lang reader "main.rkt" ★
+b inc 5 if a > 1
+a inc 1 if b < 5
+c dec -10 if a >= 1
+c inc -20 if c == 10

2017/d8/test2.rkt

@@ -0,0 +1,5 @@
+#lang reader "main.rkt" ★★
+b inc 5 if a > 1
+a inc 1 if b < 5
+c dec -10 if a >= 1
+c inc -20 if c == 10