func TestScoping(t *testing.T) {
env := environment.New(nil)
environment.Define(env, &types.Symbol{"begin"}, &types.Builtin{begin})
environment.Define(env, &types.Symbol{"+"}, &types.Builtin{add})
funcString := "(begin (define a 0) (define get-num ((lambda (a b) (define c 4) (lambda (b) (+ a b c))) 1 2)))"
f, err := parser.Parse(strings.NewReader(funcString))
if err != nil {
t.Error("Parsing funcString failed:", err)
}
if _, err := Eval(env, f); err != nil {
t.Error("Evaluating funcString failed:", err)
}
f, _ = parser.Parse(strings.NewReader("a"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating 'a' failed:", err)
} else if !types.Eqv(a, &types.Number{0}) {
t.Error("a != 0", a)
}
f, _ = parser.Parse(strings.NewReader("(get-num 8)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating (get-num) failed:", err)
} else if !types.Eqv(a, &types.Number{13}) {
t.Error("(get-num 8) != 13:", a)
}
}
func TestLambda(t *testing.T) {
env := environment.New(nil)
environment.Define(env, &types.Symbol{"+"}, &types.Builtin{add})
environment.Define(env, &types.Symbol{"begin"}, &types.Builtin{begin})
f, _ := parser.Parse(strings.NewReader("(lambda (n) n)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating lambda failed:", err, f)
} else if !types.IsSFunction(a) {
t.Error("Evaluating lambda didn't return an SFunction:", a)
}
f, _ = parser.Parse(strings.NewReader("(define add1 (lambda (n) (+ 1 n)))"))
if _, err := Eval(env, f); err != nil {
t.Error("Evaluating define lambda failed:", err)
}
if a, err := environment.Get(env, &types.Symbol{"add1"}); err != nil {
t.Error("'Get'ting add1 caused an error: ", err)
} else if !types.IsSFunction(a) {
t.Error("add1 is not an SFunction:", a)
}
f, _ = parser.Parse(strings.NewReader("(add1 1)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating (add1 1) failed:", err)
} else if !types.Eqv(a, &types.Number{2}) {
t.Error("(add1 1) != 2", a)
}
}
func TestEval(t *testing.T) {
env := environment.New(nil)
environment.Define(env, &types.Symbol{"everything"}, &types.Number{42})
environment.Define(env, &types.Symbol{"cows"}, &types.String{"moo"})
environment.Define(env, &types.Symbol{"sheep"}, &types.String{"baa"})
environment.Define(env, &types.Symbol{"+"}, &types.Builtin{add})
if r, _ := Eval(env, &types.Symbol{"everything"}); !types.Eqv(r, &types.Number{42}) {
t.Error("Var 'everything' != 42: ", r)
}
f, _ := parser.Parse(strings.NewReader("(+ 1 1)"))
if r, err := Eval(env, f); err != nil {
t.Error("Evaluating (+ 1 1) caused an error: ", err)
} else if !types.Eqv(r, &types.Number{2}) {
t.Error("(+ 1 1) != 2: ", r)
}
f, _ = parser.Parse(strings.NewReader("(+ 1 (+ 2 3))"))
if r, err := Eval(env, f); err != nil {
t.Error("Evaluating (+ 1 (+ 2 3)) caused an error: ", err)
} else if !types.Eqv(r, &types.Number{6}) {
t.Error("(+ 1 (+ 2 3)) != 6: ", r)
}
}
func main() {
env := evaluator.BuildEnvironment()
for {
l, err := readline.String("> ")
if err == io.EOF {
break
}
if err != nil {
fmt.Fprintln(os.Stderr, err)
break
}
f, err := parser.Parse(strings.NewReader(l))
if err != nil {
fmt.Fprintln(os.Stderr, err)
readline.AddHistory(l)
}
r, err := evaluator.Eval(env, f)
if err != nil {
fmt.Fprintln(os.Stderr, err)
} else {
fmt.Println(r)
}
readline.AddHistory(l)
}
}
func TestIf(t *testing.T) {
env := environment.New(nil)
f, _ := parser.Parse(strings.NewReader("(if #t 'yes 'no)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating (if #t 'yes 'no) failed:", err)
} else if !types.Eqv(a, &types.Symbol{"yes"}) {
t.Error("result != yes", a)
}
f, _ = parser.Parse(strings.NewReader("(if #f 'yes 'no)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating (if #f 'yes 'no) failed:", err)
} else if !types.Eqv(a, &types.Symbol{"no"}) {
t.Error("result != no", a)
}
}
func TestQuote(t *testing.T) {
env := environment.New(nil)
f, _ := parser.Parse(strings.NewReader("(quote moo)"))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating (quote moo) failed:", err)
} else if !types.Eqv(a, &types.Symbol{"moo"}) {
t.Error("(quote moo) != moo", a)
}
}
func TestDefine(t *testing.T) {
env := environment.New(nil)
f, _ := parser.Parse(strings.NewReader("(define answer 42)"))
if _, err := Eval(env, f); err != nil {
t.Error("Evaluating (define answer 42) failed:", err)
}
if a, err := environment.Get(env, &types.Symbol{"answer"}); err != nil {
t.Error("'Get'ting 'answer' caused an error: ", err)
} else if !types.Eqv(a, &types.Number{42}) {
t.Error("answer != 42", a)
}
}
func TestBegin(t *testing.T) {
env := environment.New(nil)
environment.Define(env, &types.Symbol{"cows"}, &types.String{"moo"})
environment.Define(env, &types.Symbol{"sheep"}, &types.String{"baa"})
environment.Define(env, &types.Symbol{"begin"}, &types.Builtin{begin})
f, _ := parser.Parse(strings.NewReader("(begin cows sheep)"))
if r, err := Eval(env, f); err != nil {
t.Error("Evaluating (begin cows sheep) caused an error: ", err)
} else if !types.Eqv(r, &types.String{"baa"}) {
t.Error("(begin cows sheep) != baa", r)
}
}
func TestFibonacci(t *testing.T) {
env := BuildEnvironment()
const funcString = "(define fib (lambda (a b max) (if (= 0 max) b (fib b (+ a b) (- max 1)))))"
f, err := parser.Parse(strings.NewReader(funcString))
if err != nil {
t.Error("Parsing funcString failed:", err)
}
if _, err := Eval(env, f); err != nil {
t.Error("Evaluating funcString failed:", err)
}
const funcString2 = "(fib 0 1 10)"
f, _ = parser.Parse(strings.NewReader(funcString2))
if a, err := Eval(env, f); err != nil {
t.Error("Evaluating", funcString2, "failed:", err)
} else if !types.Eqv(a, &types.Number{89}) {
t.Error(funcString2, "!= 89", a)
}
}