more loyal "and" and "or" methods

hugodecasta · Feb 21, 2020 · 639ea57 · 639ea57
1 parent 6026c94
commit 639ea57
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Showing 2 changed files with 42 additions and 12 deletions.
diff --git a/index.js b/index.js
@@ -116,24 +116,36 @@ let methods = {
         return handle(args[0]) == handle(args[1])
     },
     'and':function(args) {
-        for(let arg of args) {
-            if(!handle(arg)) {
-                return false
-            }
+        if(args.length == 0) {
+            return true
         }
-        return true
+        let car = handle(args[0])
+        let cdr = args.slice(1)
+        if(car === false) {
+            return false
+        }
+        if(cdr.length == 0) {
+            return car
+        }
+        return handle(['and'].concat(cdr))
     },
     'or':function(args) {
-        for(let arg of args) {
-            if(handle(arg)) {
-                return true
-            }
+        if(args.length == 0) {
+            return false
+        }
+        let car = handle(args[0])
+        let cdr = args.slice(1)
+        if(car !== false) {
+            return car
         }
-        return false
+        return handle(['or'].concat(cdr))
     },
     'not':function(args) {
-        let value = handle(args[0])
-        return !value
+        let car = handle(args[0])
+        if(car !== false) {
+            return false
+        }
+        return !car
     },
     // -----------------------------------------------------
     'null?':function(args) {

diff --git a/test.js b/test.js
@@ -100,5 +100,23 @@ test('specific scheme env', t => {
     t.is(sc2.interpret("a"), 5)
     t.is(sc3.interpret("(define a 7)"), 7)
     t.is(sc3.interpret("a"), 7)
+})
+
+test('and', t => {
+    t.is(scheme('(and #t #t #f)'),false)
+    t.is(scheme('(and #f #t #t)'),false)
+    t.is(scheme('(and #t #t #t)'),true)
+    t.is(scheme('(and #t #t 5)'),5)
+    t.is(scheme('(and 5 #t 7)'),7)
+    t.is(scheme('(and 5 #f 7)'),false)
+    t.deepEqual(scheme("(and 5 #t '(a b))"),['list','a','b'])
+})
 
+test('or', t => {
+    t.is(scheme('(or #f #f #t)'),true)
+    t.is(scheme('(or #f #t #f)'),true)
+    t.is(scheme('(or #f 7 #f)'),7)
+    t.is(scheme('(or 5 7 #f)'),5)
+    t.is(scheme('(or #f #f #f)'),false)
+    t.deepEqual(scheme("(or '(a b) #f #f)"),['list','a','b'])
 })