monkey/evaluator/stdlib_math.go at master · skx/monkey · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
package evaluator

import (
	"math"
	"math/rand"
	"time"

	"github.com/skx/monkey/object"
)

func mathAbs(args ...object.Object) object.Object {
	if len(args) != 1 {
		return newError("wrong number of arguments. got=%d, want=1",
			len(args))
	}
	switch arg := args[0].(type) {
	case *object.Integer:
		v := arg.Value
		if v < 0 {
			v = v * -1
		}
		return &object.Integer{Value: v}
	case *object.Float:
		v := arg.Value
		if v < 0 {
			v = v * -1
		}
		return &object.Float{Value: v}
	default:
		return newError("argument to `math.abs` not supported, got=%s",
			args[0].Type())
	}

}

// val = math.random()
func mathRandom(args ...object.Object) object.Object {
	return &object.Float{Value: rand.Float64()}
}

// val = math.sqrt(int);
func mathSqrt(args ...object.Object) object.Object {
	if len(args) != 1 {
		return newError("wrong number of arguments. got=%d, want=1",
			len(args))
	}
	switch arg := args[0].(type) {
	case *object.Integer:
		v := arg.Value
		return &object.Float{Value: math.Sqrt(float64(v))}
	case *object.Float:
		v := arg.Value
		return &object.Float{Value: math.Sqrt(v)}
	default:
		return newError("argument to `math.sqrt` not supported, got=%s",
			args[0].Type())
	}

}

func init() {
	//
	// Setup our random seed.
	//
	rand.Seed(time.Now().UnixNano())
	RegisterBuiltin("math.abs",
		func(env *object.Environment, args ...object.Object) object.Object {
			return (mathAbs(args...))
		})
	RegisterBuiltin("math.random",
		func(env *object.Environment, args ...object.Object) object.Object {
			return (mathRandom(args...))
		})
	RegisterBuiltin("math.sqrt",
		func(env *object.Environment, args ...object.Object) object.Object {
			return (mathSqrt(args...))
		})
}