1 files changed, 47 insertions, 0 deletions
diff --git a/neb/std/boolean.py b/neb/std/boolean.py
new file mode 100644
index 0000000..b851d7d
--- /dev/null
+++ b/neb/std/boolean.py
@@ -0,0 +1,47 @@
+from .. import TypeEnum, Environment, Arg, Builtin, evaluate
+from ..structs import *
+
+BOOLEAN = Environment()
+
+def interpretOr(symbol, args, env, ns):
+    # or returns true for the first expression that returns true
+    for arg in args:
+        ev = evaluate(arg, env, ns)
+        if not isinstance(ev, Bool):
+            raise InterpretPanic(symbol, "requires :bool arguments")
+        if ev.value == True:
+            return ev
+    return Bool(False)
+
+or_arg = Arg("arg", TypeEnum.BOOL, lazy=True)
+BOOLEAN.register("or", Builtin(interpretOr, [or_arg, or_arg], or_arg))
+
+def interpretAnd(symbol, args, env, ns):
+    # and returns false for the first expression that returns false
+    for arg in args:
+        ev = evaluate(arg, env, ns)
+        if not isinstance(ev, Bool):
+            raise InterpretPanic(symbol, "requires :bool arguments")
+        if ev.value == False:
+            return ev
+    return Bool(True)
+
+BOOLEAN.register("and", Builtin(interpretAnd, [or_arg, or_arg], or_arg))
+
+def interpretEq(symbol, args, env, ns):
+    # NOTE this currently only works for literals
+    # compare types because 0 != #false in neb
+    if type(args[0]) == type(args[1]) and args[0].value == args[1].value:
+        return Bool(True)
+    else:
+        return Bool(False)
+
+eq_arg = Arg("value", TypeEnum.LITERAL)
+BOOLEAN.register("eq?", Builtin(interpretEq, [eq_arg, eq_arg]))
+
+
+def interpretNot(symbol, args, env, ns):
+    return Bool(not args[0].value)
+
+not_arg = Arg("not", TypeEnum.BOOL)
+BOOLEAN.register("not", Builtin(interpretNot, [not_arg]))