OpenCores
URL https://opencores.org/ocsvn/openrisc/openrisc/trunk

Subversion Repositories openrisc

[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [gcc/] [testsuite/] [go.test/] [test/] [peano.go] - Blame information for rev 700

Details | Compare with Previous | View Log

Line No. Rev Author Line
1 700 jeremybenn 
// $G $F.go && $L $F.$A && ./$A.out
2 
 
3 
// Copyright 2009 The Go Authors. All rights reserved.
4 
// Use of this source code is governed by a BSD-style
5 
// license that can be found in the LICENSE file.
6 
 
7 
package main
8 
 
9 
type Number *Number
10 
 
11 
// -------------------------------------
12 
// Peano primitives
13 
 
14 
func zero() *Number {
15 
        return nil
16 
}
17 
 
18 
func is_zero(x *Number) bool {
19 
        return x == nil
20 
}
21 
 
22 
func add1(x *Number) *Number {
23 
        e := new(Number)
24 
        *e = x
25 
        return e
26 
}
27 
 
28 
func sub1(x *Number) *Number {
29 
        return *x
30 
}
31 
 
32 
func add(x, y *Number) *Number {
33 
        if is_zero(y) {
34 
                return x
35 
        }
36 
 
37 
        return add(add1(x), sub1(y))
38 
}
39 
 
40 
func mul(x, y *Number) *Number {
41 
        if is_zero(x) || is_zero(y) {
42 
                return zero()
43 
        }
44 
 
45 
        return add(mul(x, sub1(y)), x)
46 
}
47 
 
48 
func fact(n *Number) *Number {
49 
        if is_zero(n) {
50 
                return add1(zero())
51 
        }
52 
 
53 
        return mul(fact(sub1(n)), n)
54 
}
55 
 
56 
// -------------------------------------
57 
// Helpers to generate/count Peano integers
58 
 
59 
func gen(n int) *Number {
60 
        if n > 0 {
61 
                return add1(gen(n - 1))
62 
        }
63 
 
64 
        return zero()
65 
}
66 
 
67 
func count(x *Number) int {
68 
        if is_zero(x) {
69 
                return 0
70 
        }
71 
 
72 
        return count(sub1(x)) + 1
73 
}
74 
 
75 
func check(x *Number, expected int) {
76 
        var c = count(x)
77 
        if c != expected {
78 
                print("error: found ", c, "; expected ", expected, "\n")
79 
                panic("fail")
80 
        }
81 
}
82 
 
83 
// -------------------------------------
84 
// Test basic functionality
85 
 
86 
func init() {
87 
        check(zero(), 0)
88 
        check(add1(zero()), 1)
89 
        check(gen(10), 10)
90 
 
91 
        check(add(gen(3), zero()), 3)
92 
        check(add(zero(), gen(4)), 4)
93 
        check(add(gen(3), gen(4)), 7)
94 
 
95 
        check(mul(zero(), zero()), 0)
96 
        check(mul(gen(3), zero()), 0)
97 
        check(mul(zero(), gen(4)), 0)
98 
        check(mul(gen(3), add1(zero())), 3)
99 
        check(mul(add1(zero()), gen(4)), 4)
100 
        check(mul(gen(3), gen(4)), 12)
101 
 
102 
        check(fact(zero()), 1)
103 
        check(fact(add1(zero())), 1)
104 
        check(fact(gen(5)), 120)
105 
}
106 
 
107 
// -------------------------------------
108 
// Factorial
109 
 
110 
var results = [...]int{
111 
        1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800,
112 
        39916800, 479001600,
113 
}
114 
 
115 
func main() {
116 
        for i := 0; i <= 9; i++ {
117 
                if f := count(fact(gen(i))); f != results[i] {
118 
                        println("FAIL:", i, "!:", f, "!=", results[i])
119 
                        panic(0)
120 
                }
121 
        }
122 
}

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.