diff options
Diffstat (limited to 'lib/pure/base64.nim')
| -rw-r--r-- | lib/pure/base64.nim | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/lib/pure/base64.nim b/lib/pure/base64.nim index 9b7af88ef..bc01a9164 100644 --- a/lib/pure/base64.nim +++ b/lib/pure/base64.nim @@ -180,7 +180,7 @@ proc encode*(s: string, safe = false): string = assert encode("Hello World") == "SGVsbG8gV29ybGQ=" encodeImpl() -proc encodeMime*(s: string, lineLen = 75, newLine = "\r\n"): string = +proc encodeMime*(s: string, lineLen = 75.Positive, newLine = "\r\n"): string = ## Encodes `s` into base64 representation as lines. ## Used in email MIME format, use `lineLen` and `newline`. ## @@ -191,11 +191,25 @@ proc encodeMime*(s: string, lineLen = 75, newLine = "\r\n"): string = ## * `decode proc<#decode,string>`_ for decoding a string runnableExamples: assert encodeMime("Hello World", 4, "\n") == "SGVs\nbG8g\nV29y\nbGQ=" - result = newStringOfCap(encodeSize(s.len)) - for i, c in encode(s): - if i != 0 and (i mod lineLen == 0): - result.add(newLine) - result.add(c) + template cpy(l, src, idx) = + b = l + while i < b: + result[i] = src[idx] + inc i + inc idx + + if s.len == 0: return + let e = encode(s) + if e.len <= lineLen or newLine.len == 0: + return e + result = newString(e.len + newLine.len * ((e.len div lineLen) - int(e.len mod lineLen == 0))) + var i, j, k, b: int + let nd = e.len - lineLen + while j < nd: + cpy(i + lineLen, e, j) + cpy(i + newLine.len, newLine, k) + k = 0 + cpy(result.len, e, j) proc initDecodeTable*(): array[256, char] = # computes a decode table at compile time |