issue-1: added add, sub, mup, div, and mod

ucl/builtins.go

@@ -53,6 +53,120 @@ func addBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 	return intObject(n), nil
 }
 
+func subBuiltin(ctx context.Context, args invocationArgs) (object, error) {
+	if len(args.args) == 0 {
+		return intObject(0), nil
+	}
+
+	n := 0
+	for i, a := range args.args {
+		var p int
+		switch t := a.(type) {
+		case intObject:
+			p = int(t)
+		case strObject:
+			v, err := strconv.Atoi(string(t))
+			if err != nil {
+				return nil, fmt.Errorf("arg %v of 'sub' not convertable to an int", i)
+			}
+			p = v
+		default:
+			return nil, fmt.Errorf("arg %v of 'sub' not convertable to an int", i)
+		}
+		if i == 0 {
+			n = p
+		} else {
+			n -= p
+		}
+	}
+
+	return intObject(n), nil
+}
+
+func mupBuiltin(ctx context.Context, args invocationArgs) (object, error) {
+	if len(args.args) == 0 {
+		return intObject(1), nil
+	}
+
+	n := 1
+	for i, a := range args.args {
+		switch t := a.(type) {
+		case intObject:
+			n *= int(t)
+		case strObject:
+			v, err := strconv.Atoi(string(t))
+			if err != nil {
+				return nil, fmt.Errorf("arg %v of 'mup' not convertable to an int", i)
+			}
+			n *= v
+		default:
+			return nil, fmt.Errorf("arg %v of 'mup' not convertable to an int", i)
+		}
+	}
+
+	return intObject(n), nil
+}
+
+func divBuiltin(ctx context.Context, args invocationArgs) (object, error) {
+	if len(args.args) == 0 {
+		return intObject(1), nil
+	}
+
+	n := 1
+	for i, a := range args.args {
+		var p int
+		switch t := a.(type) {
+		case intObject:
+			p = int(t)
+		case strObject:
+			v, err := strconv.Atoi(string(t))
+			if err != nil {
+				return nil, fmt.Errorf("arg %v of 'div' not convertable to an int", i)
+			}
+			p = v
+		default:
+			return nil, fmt.Errorf("arg %v of 'div' not convertable to an int", i)
+		}
+		if i == 0 {
+			n = p
+		} else {
+			n /= p
+		}
+	}
+
+	return intObject(n), nil
+}
+
+func modBuiltin(ctx context.Context, args invocationArgs) (object, error) {
+	if len(args.args) == 0 {
+		return intObject(0), nil
+	}
+
+	n := 0
+	for i, a := range args.args {
+		var p int
+		switch t := a.(type) {
+		case intObject:
+			p = int(t)
+		case strObject:
+			v, err := strconv.Atoi(string(t))
+			if err != nil {
+				return nil, fmt.Errorf("arg %v of 'mod' not convertable to an int", i)
+			}
+			p = v
+		default:
+			return nil, fmt.Errorf("arg %v of 'mod' not convertable to an int", i)
+		}
+		if i == 0 {
+			n = p
+		} else {
+			n %= p
+		}
+	}
+
+	return intObject(n), nil
+}
+
 func setBuiltin(ctx context.Context, args invocationArgs) (object, error) {
 	if err := args.expectArgn(2); err != nil {
 		return nil, err

ucl/inst.go

@@ -71,6 +71,10 @@ func New(opts ...InstOption) *Inst {
 	rootEC.addCmd("int", invokableFunc(intBuiltin))
 
 	rootEC.addCmd("add", invokableFunc(addBuiltin))
+	rootEC.addCmd("sub", invokableFunc(subBuiltin))
+	rootEC.addCmd("mup", invokableFunc(mupBuiltin))
+	rootEC.addCmd("div", invokableFunc(divBuiltin))
+	rootEC.addCmd("mod", invokableFunc(modBuiltin))
 
 	rootEC.addCmd("cat", invokableFunc(concatBuiltin))
 	rootEC.addCmd("break", invokableFunc(breakBuiltin))

ucl/testbuiltins_test.go

@@ -1093,3 +1093,59 @@ func TestBuiltins_Int(t *testing.T) {
 		})
 	}
 }
+
+func TestBuiltins_AddSubMupDivMod(t *testing.T) {
+	tests := []struct {
+		desc    string
+		expr    string
+		want    int
+		wantErr bool
+	}{
+		{desc: "add 1", expr: `add 1 2`, want: 3},
+		{desc: "add 2", expr: `add "3" 5`, want: 8},
+		{desc: "add 3", expr: `add 1 "2" 8`, want: 11},
+		{desc: "add 4", expr: `add 1`, want: 1},
+		{desc: "add 5", expr: `add`, want: 0},
+		{desc: "sub 1", expr: `sub 9 3`, want: 6},
+		{desc: "sub 2", expr: `sub 2 "5"`, want: -3},
+		{desc: "sub 3", expr: `sub 8 1 8`, want: -1},
+		{desc: "sub 4", expr: `sub 4`, want: 4},
+		{desc: "sub 5", expr: `sub`, want: 0},
+		{desc: "mup 1", expr: `mup 2 4`, want: 8},
+		{desc: "mup 2", expr: `mup 3 "4" 5`, want: 60},
+		{desc: "mup 3", expr: `mup 7`, want: 7},
+		{desc: "mup 4", expr: `mup`, want: 1},
+		{desc: "div 1", expr: `div 8 4`, want: 2},
+		{desc: "div 2", expr: `div "7" 4`, want: 1},
+		{desc: "div 3", expr: `div 7`, want: 7},
+		{desc: "div 4", expr: `div`, want: 1},
+		{desc: "mod 1", expr: `mod 2 3`, want: 2},
+		{desc: "mod 2", expr: `mod "7" 4`, want: 3},
+		{desc: "mod 3", expr: `mod 8 4`, want: 0},
+		{desc: "mod 4", expr: `mod 3`, want: 3},
+		{desc: "mod 5", expr: `mod`, want: 0},
+
+		{desc: "add err", expr: `add [] [:]`, wantErr: true},
+		{desc: "sub err", expr: `sub [] [:]`, wantErr: true},
+		{desc: "mup err", expr: `mup [] [:]`, wantErr: true},
+		{desc: "div err", expr: `div [] [:]`, wantErr: true},
+		{desc: "mod err", expr: `mod [] [:]`, wantErr: true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.desc, func(t *testing.T) {
+			ctx := context.Background()
+			outW := bytes.NewBuffer(nil)
+
+			inst := New(WithOut(outW), WithTestBuiltin())
+
+			eqRes, err := inst.Eval(ctx, tt.expr)
+			if tt.wantErr {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, tt.want, eqRes)
+			}
+		})
+	}
+}