Fix match behavior for lone nil.

src/boot/boot.janet

@@ -1317,7 +1317,7 @@
       ~(if (= ,pattern ,expr) ,(onmatch) ,sentinel)
       (do
         (put seen pattern true)
-        ~(if (= nil (def ,pattern ,expr)) ,sentinel ,(onmatch))))
+        ~(do (def ,pattern ,expr) ,(onmatch))))
 
     (and (tuple? pattern) (= :parens (tuple/type pattern)))
     (if (and (= (pattern 0) '@) (symbol? (pattern 1)))
@@ -1334,12 +1334,14 @@
       (var i -1)
       (with-idemp
         $arr expr
-        ~(if (indexed? ,$arr)
-           ,((fn aux []
-               (++ i)
-               (if (= i len)
-                 (onmatch)
-                 (match-1 (in pattern i) (tuple in $arr i) aux seen))))
+        ~(if (,indexed? ,$arr)
+           (if (< (,length ,$arr) ,len)
+             ,sentinel
+             ,((fn aux []
+                 (++ i)
+                 (if (= i len)
+                   (onmatch)
+                   (match-1 (in pattern i) (tuple in $arr i) aux seen)))))
            ,sentinel)))
 
     (dictionary? pattern)
@@ -1347,12 +1349,12 @@
       (var key nil)
       (with-idemp
         $dict expr
-        ~(if (dictionary? ,$dict)
+        ~(if (,dictionary? ,$dict)
            ,((fn aux []
                (set key (next pattern key))
                (if (= key nil)
                  (onmatch)
-                 (match-1 (in pattern key) (tuple in $dict key) aux seen))))
+                 (match-1 [(in pattern key) [not= (in pattern key) nil]] [in $dict key] aux seen))))
            ,sentinel)))
 
     :else ~(if (= ,pattern ,expr) ,(onmatch) ,sentinel)))

test/suite8.janet

@@ -99,4 +99,12 @@
 
 (assert (= 10 (prompt :a (for i 0 10 (inner-loop2 i)))) "prompt 3")
 
+# Match checks
+
+(assert (= :hi (match nil nil :hi)) "match 1")
+(assert (= :hi (match {:a :hi} {:a a} a)) "match 2")
+(assert (= nil (match {:a :hi} {:a a :b b} a)) "match 3")
+(assert (= nil (match [1 2] [a b c] a)) "match 4")
+(assert (= 2 (match [1 2] [a b] b)) "match 5")
+
 (end-suite)