add examples for has-key? and has-value?

examples/has-key_63.janet

@@ -0,0 +1,22 @@
+# tables
+(has-key? @{} 0) # -> false
+(has-key? @{:key1 "foo" :key2 "bar"} :key1) # -> true
+(has-key? @{:key1 "foo" :key2 "bar"} :key3) # -> false
+
+# structs
+(has-key? {} 0) # -> false
+(has-key? {:key1 "foo" :key2 "bar"} :key1) # -> true
+(has-key? {:key1 "foo" :key2 "bar"} :key3) # -> false
+
+# buffers, tuples and arrays check for index as key
+(has-key? "" 0) # -> false
+(has-key? "a" 0) # -> true
+(has-key? "a" 1) # -> false
+
+(has-key? [] 0) # -> false
+(has-key? ["a" "b" "c"] 1) # -> true
+(has-key? ["a" "b" "c"] 4) # -> false
+
+(has-key? @[] 0) # -> false
+(has-key? @["a" "b" "c"] 1) # -> true
+(has-key? @["a" "b" "c"] 4) # -> false

examples/has-value_63.janet

@@ -0,0 +1,30 @@
+# tables
+(has-value? @{} 0) # -> false
+(has-value? @{:key1 "foo" :key2 "bar"} "foo") # -> true
+(has-value? @{:key1 "foo" :key2 "bar"} "hello") # -> false
+(has-value? @{:key1 "foo" :key2 "bar"} nil) # -> false
+
+# structs
+(has-value? {} 0) # -> false
+(has-value? {:key1 "foo" :key2 "bar"} "foo") # -> true
+(has-value? {:key1 "foo" :key2 "bar"} "hello") # -> false
+(has-value? {:key1 "foo" :key2 "bar"} nil) # -> false
+
+# buffers - individual values are bytes
+(has-value? "" 0) # -> false
+(has-value? "" nil) # -> false
+(has-value? "abc" 97) # -> true
+(has-value? "abc" "a") # -> false
+(has-value? "abc" 'a) # -> false
+
+# tuples
+(has-value? [] 0) # -> false
+(has-value? ["a" "b" "c"] "a") # -> true
+(has-value? ["a" "b" "c"] 'a) # -> false
+(has-value? ["a" "b" "c"] 97) # -> false
+
+# arrays
+(has-value? @[] 0) # -> false
+(has-value? @["a" "b" "c"] "a") # -> true
+(has-value? @["a" "b" "c"] 'a) # -> false
+(has-value? @["a" "b" "c"] 97) # -> false