utf8 support

evaluator/evaluator_test.go

@@ -330,7 +330,7 @@ func TestStringConcatenation(t *testing.T) {
 	}
 }
 
-func TestBuiltinFunction(t *testing.T) {
+func TestBuiltinFunctions(t *testing.T) {
 	tests := []struct {
 		input    string
 		expected interface{}
@@ -340,6 +340,20 @@ func TestBuiltinFunction(t *testing.T) {
 		{`len("hello world")`, 11},
 		{`len(1)`, "argument to `len` not supported, got INTEGER"},
 		{`len("one", "two")`, "wrong number of arguments. got=2, want=1"},
+		{`len("∑")`, 1},
+		{`len([1, 2, 3])`, 3},
+		{`len([])`, 0},
+		{`first([1, 2, 3])`, 1},
+		{`first([])`, nil},
+		{`first(1)`, "argument to `first` must be ARRAY, got INTEGER"},
+		{`last([1, 2, 3])`, 3},
+		{`last([])`, nil},
+		{`last(1)`, "argument to `last` must be ARRAY, got INTEGER"},
+		{`rest([1, 2, 3])`, []int{2, 3}},
+		{`rest([])`, nil},
+		{`push([], 1)`, []int{1}},
+		{`push(1, 1)`, "argument to `push` must be ARRAY, got INTEGER"},
+		{`puts("Hello World")`, nil},
 	}
 
 	for _, tt := range tests {
@@ -351,11 +365,13 @@ func TestBuiltinFunction(t *testing.T) {
 		case string:
 			errObj, ok := evaluated.(*object.Error)
 			if !ok {
-				t.Errorf("object is not Error. got=%T (%+v)", evaluated, evaluated)
+				t.Errorf("object is not Error. got=%T (%+v)",
+					evaluated, evaluated)
 				continue
 			}
 			if errObj.Message != expected {
-				t.Errorf("wrong error message. expected=%q, got=%q", expected, errObj.Message)
+				t.Errorf("wrong error message. expected=%q, got=%q",
+					expected, errObj.Message)
 			}
 		}
 	}