fix: rework if to support nested expressions

wat/printer.rkt

@@ -121,8 +121,13 @@
         [(cons (Call f) is) (string-append (tabs ntabs) "(call $" (symbol->string f) ")\n" 
         (parse-instruction-list is ntabs))]
         [(cons (WatIf p t f) is) (string-append
+            (parse-instruction-list (seq p) ntabs)
             (tabs ntabs) "(if (result i64)\n"
-            (parse-instruction-list (seq p t f) (add1 ntabs))
+            (tabs (add1 ntabs)) "(then\n" (parse-instruction-list (seq t) (+ 2 ntabs))
+            (tabs (add1 ntabs)) ")\n"
+            (tabs (add1 ntabs)) "(else\n"
+            (parse-instruction-list (seq f) (+ 2 ntabs))
+            (tabs (add1 ntabs)) ")\n"
             (tabs ntabs) ")\n"
             (parse-instruction-list is ntabs))]
         [(cons (ConstT t n) is) (string-append
@@ -161,9 +166,20 @@
             (tabs ntabs) ")\n"
             (parse-instruction-list is ntabs)
         )]
+        [(cons (Loop e n) is) (string-append (tabs ntabs) "(loop $" (symbol->string n) "\n"
+            (parse-instruction-list (seq e) (add1 ntabs))
+            (tabs ntabs) ")\n"
+            (parse-instruction-list is ntabs)
+        )]
+        [(cons (BranchIf p n) is) (string-append (tabs ntabs) "(br_if\n"
+            (parse-instruction-list (seq p) (add1 ntabs))
+            (tabs ntabs) "$" (symbol->string n) ")\n"
+            (parse-instruction-list is ntabs)
+        )]
         [(cons (Drop) is) (string-append (tabs ntabs) "(drop)\n"
             (parse-instruction-list is ntabs)
         )]
+        [(cons (Load) is) (parse-instruction-list is ntabs)]
         [(cons x _) (parse-error "Instruction not recognized:" x)]
         [x (parse-error "Expected instruction list, got:" x)]))