std::encoding::base32: get destination slice for the Encode and Decod…

…e functions

std/encoding/base32/base32.jule

@@ -10,11 +10,11 @@ static t32 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"
 // Standard byte for padding.
 const paddingByte = '='
 
-// Encodes source bytes with standard base32 table.
+// Encodes source bytes into dest with standard base32 table.
 // Returns encoded base32 bytes if success, nil slice if not.
 // Adds padding if pad is true.
-fn Encode(src: []byte, pad: bool): []byte {
-    let mut dest: []byte = nil
+// Algorithm will call the append function to append dest.
+fn Encode(mut dest: []byte, src: []byte, pad: bool): []byte {
     let mut bits: u64 = 0
     let mut buffer: u32 = 0
     let p = &t32[0]
@@ -58,11 +58,11 @@ fn Encode(src: []byte, pad: bool): []byte {
     ret dest
 }
 
-// Decodes source bytes with standard base32 table.
+// Decodes source bytes into dest with standard base32 table.
 // Returns decoded bytes if success, nil slice if not.
 // Detects padding by default, no required padding specification.
-fn Decode(src: []byte): []byte {
-    let mut dest: []byte = nil
+// Algorithm will call the append function to append dest.
+fn Decode(mut dest: []byte, src: []byte): []byte {
     let mut buffer: u32 = 0
     let mut bits: u64 = 0
     for _, b in src {

std/encoding/base32/base32_test.jule

@@ -29,7 +29,7 @@ static encodeDecodeMap = [
 #test
 fn testEncode(t: &T) {
     for _, case in encodeDecodeMap {
-        let r = Encode(case[0], true)
+        let r = Encode(nil, case[0], true)
         let d = case[1]
         if len(r) != len(d) {
             t.Fail()
@@ -47,7 +47,7 @@ fn testEncode(t: &T) {
 #test
 fn testDecode(t: &T) {
     for _, case in encodeDecodeMap {
-        let r = Decode(case[1])
+        let r = Decode(nil, case[1])
         let d = case[0]
         if len(r) != len(d) {
             t.Fail()