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authorBruce Hill <bruce@bruce-hill.com>2025-04-07 18:14:20 -0400
committerBruce Hill <bruce@bruce-hill.com>2025-04-07 18:14:20 -0400
commit3efd7d9cfbd330ebb45f39648ee96a3e429a06f9 (patch)
tree29acb9e2b2370bd155fed24fba79d01b553a24f3 /lib/base64/base64.tm
parent15fabfb9be3e3620e4b96983a49017116cea40e2 (diff)
Move core libraries into their own folder
Diffstat (limited to 'lib/base64/base64.tm')
-rw-r--r--lib/base64/base64.tm96
1 files changed, 96 insertions, 0 deletions
diff --git a/lib/base64/base64.tm b/lib/base64/base64.tm
new file mode 100644
index 00000000..bf512a83
--- /dev/null
+++ b/lib/base64/base64.tm
@@ -0,0 +1,96 @@
+# Base 64 encoding and decoding
+
+_enc := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".bytes()
+
+_EQUAL_BYTE := Byte(0x3D)
+
+_dec : [Byte] = [
+ 255, 255, 255, 255, 255, 255, 255, 255,
+ 255, 255, 255, 255, 255, 255, 255, 255,
+ 255, 255, 255, 255, 255, 255, 255, 255,
+ 255, 255, 255, 255, 255, 255, 255, 255,
+ 255, 255, 255, 255, 255, 255, 255, 255,
+ 255, 255, 255, 62, 255, 255, 255, 63,
+ 52, 53, 54, 55, 56, 57, 58, 59,
+ 60, 61, 255, 255, 255, 255, 255, 255,
+ 255, 0, 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, 255, 255, 255, 255, 255,
+ 255, 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, 255, 255, 255, 255, 255,
+]
+
+lang Base64
+ func parse(text:Text -> Base64?)
+ return Base64.from_bytes(text.bytes())
+
+ func from_bytes(bytes:[Byte] -> Base64?)
+ output := &[Byte(0) for _ in bytes.length * 4 / 3 + 4]
+ src := Int64(1)
+ dest := Int64(1)
+ while src + 2 <= Int64(bytes.length)
+ chunk24 := (
+ (Int32(bytes[src]) <<< 16) or (Int32(bytes[src+1]) <<< 8) or Int32(bytes[src+2])
+ )
+ src += 3
+
+ output[dest] = _enc[1 + ((chunk24 >>> 18) and 0b111111)]
+ output[dest+1] = _enc[1 + ((chunk24 >>> 12) and 0b111111)]
+ output[dest+2] = _enc[1 + ((chunk24 >>> 6) and 0b111111)]
+ output[dest+3] = _enc[1 + (chunk24 and 0b111111)]
+ dest += 4
+
+ if src + 1 == bytes.length
+ chunk16 := (
+ (Int32(bytes[src]) <<< 8) or Int32(bytes[src+1])
+ )
+ output[dest] = _enc[1 + ((chunk16 >>> 10) and 0b11111)]
+ output[dest+1] = _enc[1 + ((chunk16 >>> 4) and 0b111111)]
+ output[dest+2] = _enc[1 + ((chunk16 <<< 2)and 0b111111)]
+ output[dest+3] = _EQUAL_BYTE
+ else if src == bytes.length
+ chunk8 := Int32(bytes[src])
+ output[dest] = _enc[1 + ((chunk8 >>> 2) and 0b111111)]
+ output[dest+1] = _enc[1 + ((chunk8 <<< 4) and 0b111111)]
+ output[dest+2] = _EQUAL_BYTE
+ output[dest+3] = _EQUAL_BYTE
+
+ return Base64.from_text(Text.from_bytes(output[]) or return none)
+
+ func decode_text(b64:Base64 -> Text?)
+ return Text.from_bytes(b64.decode_bytes() or return none)
+
+ func decode_bytes(b64:Base64 -> [Byte]?)
+ bytes := b64.text.bytes()
+ output := &[Byte(0) for _ in bytes.length/4 * 3]
+ src := Int64(1)
+ dest := Int64(1)
+ while src + 3 <= Int64(bytes.length)
+ chunk24 := (
+ (Int32(_dec[1+bytes[src]]) <<< 18) or
+ (Int32(_dec[1+bytes[src+1]]) <<< 12) or
+ (Int32(_dec[1+bytes[src+2]]) <<< 6) or
+ Int32(_dec[1+bytes[src+3]])
+ )
+ src += 4
+
+ output[dest] = Byte((chunk24 >>> 16) and 0xFF)
+ output[dest+1] = Byte((chunk24 >>> 8) and 0xFF)
+ output[dest+2] = Byte(chunk24 and 0xFF)
+ dest += 3
+
+ while output[-1] == 0xFF
+ output[] = output.to(-2)
+
+ return output[]
+
+func main(input=(/dev/stdin), decode=no)
+ if decode
+ b := Base64.from_text(input.read()!)
+ say(b.decode_text()!)
+ else
+ text := input.read()!
+ say(Base64.parse(text)!.text)