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Routines for converting between different character encodings. On UNIX, this uses the iconv library, on Windows the Windows API.

The following example shows how to change character encodings.

Example:

  1. import std/encodings
  2. when defined(windows):
  3.   let
  4.     orig = "öäüß"
  5.     # convert `orig` from "UTF-8" to "CP1252"
  6.     cp1252 = convert(orig, "CP1252", "UTF-8")
  7.     # convert `cp1252` from "CP1252" to "ibm850"
  8.     ibm850 = convert(cp1252, "ibm850", "CP1252")
  9.     current = getCurrentEncoding()
  10.   assert orig == "\195\182\195\164\195\188\195\159"
  11.   assert ibm850 == "\148\132\129\225"
  12.   assert convert(ibm850, current, "ibm850") == orig

The example below uses a reuseable EncodingConverter object which is created by open with destEncoding and srcEncoding specified. You can use convert on this object multiple times.

Example:

  1. import std/encodings
  2. when defined(windows):
  3.   var fromGB2312 = open("utf-8", "gb2312")
  4.   let first = "\203\173\197\194\163\191\210\187" &
  5.       "\203\242\209\204\211\234\200\206\198\189\201\250"
  6.   assert fromGB2312.convert(first) == "谁怕？一蓑烟雨任平生"
  8.   let second = "\211\208\176\215\205\183\200\231" &
  9.       "\208\194\163\172\199\227\184\199\200\231\185\202"
  10.   assert fromGB2312.convert(second) == "有白头如新，倾盖如故"

Imports

os, parseutils, strutils

Types

  1. EncodingConverter = object

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  1. EncodingError = object of ValueError

Exception that is raised for encoding errors. Source Edit

Procs

  1. proc close(c: EncodingConverter) {....raises: [], tags: [], forbids: [].}

Frees the resources the converter c holds. Source Edit 

  1. proc codePageToName(c: CodePage): string {....raises: [], tags: [], forbids: [].}

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  1. proc convert(c: EncodingConverter; s: string): string {.
  2.     ...raises: [EncodingError, OSError], tags: [], forbids: [].}

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  1. proc convert(s: string; destEncoding = "UTF-8"; srcEncoding = "CP1252"): string {.
  2.     ...raises: [ValueError, EncodingError, EncodingError, OSError], tags: [],
  3.     forbids: [].}

Converts s to destEncoding. It assumed that s is in srcEncoding. This opens a converter, uses it and closes it again and is thus more convenient but also likely less efficient than re-using a converter.

Warning: UTF-16BE and UTF-32 conversions are not supported on Windows.

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  1. proc getCurrentEncoding(uiApp = false): string {....raises: [], tags: [],
  2.     forbids: [].}

Retrieves the current encoding. On Unix, “UTF-8” is always returned. The uiApp parameter is Windows specific. If true, the UI’s code-page is returned, if false, the Console’s code-page is returned. Source Edit 

  1. proc nameToCodePage(name: string): CodePage {....raises: [ValueError], tags: [],
  2.     forbids: [].}

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  1. proc open(destEncoding = "UTF-8"; srcEncoding = "CP1252"): EncodingConverter {.
  2.     ...raises: [ValueError, EncodingError], tags: [], forbids: [].}

Opens a converter that can convert from srcEncoding to destEncoding. Raises EncodingError if it cannot fulfill the request. Source Edit