68 lines
1.5 KiB
V
68 lines
1.5 KiB
V
module rand
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import time
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// init initializes the default RNG.
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fn init() {
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default_rng = new_default()
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}
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pub fn string(len int) string {
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result := ''
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#
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#const characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
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#const charactersLength = characters.length;
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#for (let i = 0;i < len.val;i++)
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#result.str += characters.charAt(Math.random() * charactersLength);
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return result
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}
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const (
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ulid_encoding = '0123456789ABCDEFGHJKMNPQRSTVWXYZ'
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)
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// ulid generates an Unique Lexicographically sortable IDentifier.
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// See https://github.com/ulid/spec .
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// NB: ULIDs can leak timing information, if you make them public, because
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// you can infer the rate at which some resource is being created, like
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// users or business transactions.
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// (https://news.ycombinator.com/item?id=14526173)
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pub fn ulid() string {
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return ulid_at_millisecond(u64(time.utc().unix_time_milli()))
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}
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// ulid_at_millisecond does the same as `ulid` but takes a custom Unix millisecond timestamp via `unix_time_milli`.
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pub fn ulid_at_millisecond(unix_time_milli u64) string {
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mut buf := []byte{cap: 27}
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mut t := unix_time_milli
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mut i := 9
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for i >= 0 {
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buf[i] = rand.ulid_encoding[int(t & 0x1f)]
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t = t >> 5
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i--
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}
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mut x := default_rng.u64()
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i = 10
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for i < 19 {
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buf[i] = rand.ulid_encoding[int(x & 0x1f)]
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x = x >> 5
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i++
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}
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x = default_rng.u64()
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for i < 26 {
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buf[i] = rand.ulid_encoding[int(x & 0x1f)]
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x = x >> 5
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i++
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}
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res := ''
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println(buf)
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#res.str = buf.arr.arr.map(String.fromCharCode).join('')
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return res
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}
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