feat(examples): add package cford32, add method seqid.ID.String

examples/gno.land/p/demo/cford32/LICENSE

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+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

examples/gno.land/p/demo/cford32/README.md

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+# cford32
+
+```
+package cford32 // import "gno.land/p/demo/cford32"
+
+Package cford32 implements a base32-like encoding/decoding package, with the
+encoding scheme specified by Douglas Crockford.
+
+From the website, the requirements of said encoding scheme are to:
+
+  - Be human readable and machine readable.
+  - Be compact. Humans have difficulty in manipulating long strings of arbitrary
+    symbols.
+  - Be error resistant. Entering the symbols must not require keyboarding
+    gymnastics.
+  - Be pronounceable. Humans should be able to accurately transmit the symbols
+    to other humans using a telephone.
+
+This is slightly different from a simple difference in encoding table from
+the Go's stdlib `encoding/base32`, as when decoding the characters i I l L are
+parsed as 1, and o O is parsed as 0.
+
+This package additionally provides ways to encode uint64's efficiently, as well
+as efficient encoding to a lowercase variation of the encoding. The encodings
+never use paddings.
+
+# Uint64 Encoding
+
+Aside from lower/uppercase encoding, there is a compact encoding, allowing to
+encode all values in [0,2^34), and the full encoding, allowing all values in
+[0,2^64). The compact encoding uses 7 characters, and the full encoding uses 13
+characters. Both are parsed unambiguously by the Uint64 decoder.
+
+The compact encodings have the first character between ['0','f'], while the
+full encoding's first character ranges between ['g','z']. Practically, in your
+usage of the package, you should consider which one to use and stick with it,
+while considering that the compact encoding, once it reaches 2^34, automatically
+switches to the full encoding. The properties of the generated strings are still
+maintained: for instance, any two encoded uint64s x,y consistently generated
+with the compact encoding, if the numeric value is x < y, will also be x < y in
+lexical ordering. However, values [0,2^34) have a "double encoding", which if
+mixed together lose the lexical ordering property.
+
+The Uint64 encoding is most useful for generating string versions of Uint64 IDs.
+Practically, it allows you to retain sleek and compact IDs for your applcation
+for the first 2^34 (>17 billion) entities, while seamlessly rolling over to the
+full encoding should you exceed that. You are encouraged to use it unless you
+have a requirement or preferences for IDs consistently being always the same
+size.
+
+To use the cford32 encoding for IDs, you may want to consider using package
+gno.land/p/demo/seqid.
+
+[specified by Douglas Crockford]: https://www.crockford.com/base32.html
+
+func AppendCompact(id uint64, b []byte) []byte
+func AppendDecode(dst, src []byte) ([]byte, error)
+func AppendEncode(dst, src []byte) []byte
+func AppendEncodeLower(dst, src []byte) []byte
+func Decode(dst, src []byte) (n int, err error)
+func DecodeString(s string) ([]byte, error)
+func DecodedLen(n int) int
+func Encode(dst, src []byte)
+func EncodeLower(dst, src []byte)
+func EncodeToString(src []byte) string
+func EncodeToStringLower(src []byte) string
+func EncodedLen(n int) int
+func NewDecoder(r io.Reader) io.Reader
+func NewEncoder(w io.Writer) io.WriteCloser
+func NewEncoderLower(w io.Writer) io.WriteCloser
+func PutCompact(id uint64) []byte
+func PutUint64(id uint64) [13]byte
+func PutUint64Lower(id uint64) [13]byte
+func Uint64(b []byte) (uint64, error)
+type CorruptInputError int64
+```