Accept char iterator as input

[tmfink]

Work-in-progress to handle #3.

Please let me know your thoughts on this style. I just worked on katakana_to_hiragana(). Once we figure out how the best way to do this, I will work on the other modules.

Add iterator input APIs to

• is_hiragana
  • is_hiragana()
• is_japanese
  • is_japanese()
• is_kana
  • is_kana()
• is_kanji
  • contains_kanji()
  • is_kanji()
• is_katakana
  • is_katakana()
• is_mixed
  • is_mixed()
  • is_mixed_pass_kanji()
• is_romaji
  • is_romaji()
• to_hiragana
  • to_hiragana()
  • to_hiragana_with_opt()
• to_kana
  • to_kana()
  • to_kana_with_opt()
• to_katakana
  • to_katakana()
  • to_katakana_with_opt()
• to_romaji
  • to_romaji()
  • to_romaji_with_opt()
• tokenize
  • tokenize()
  • tokenize_detailed()
  • tokenize_with_opt()
• trim_okurigana
  • is_invalid_matcher()
  • is_leading_without_initial_kana()
  • is_trailing_without_final_kana()
  • trim_okurigana()
  • trim_okurigana_with_opt()
• utils
  • hiragana_to_katakana()
  • katakana_to_hiragana()
  • romaji_to_hiragana()

[PSeitz]

There is a place where the next char is peeked:

wana_kana_rust/src/to_hiragana.rs

Lines 29 to 31 in c45ebcd

	} else if is_romaji(input) || input.chars().next().map(|c| is_char_english_punctuation(c)).unwrap_or(false) {
	// TODO: is it correct to check only the first char (see src\utils\isCharEnglishPunctuation.js)
	romaji_to_hiragana(input, config)

So it would require a peekable iterator I think
https://doc.rust-lang.org/std/iter/struct.Peekable.html

There may be other similar cases.

[PSeitz]

On second thought, we could always just use the minimal api instead of a uniform one, which would not require Peekable here. What do you think?

[tmfink]

On second thought, we could always just use the minimal api instead of a uniform one, which would not require Peekable here. What do you think?

@PSeitz What do you mean by minimal vs. uniform API?

In some cases, we can get away with avoiding the "direct indexing" approach. For katakana_iter_to_hiragana_with_opt(), I added a previous_char variable to track the previous character (instead of indexing into the previous index).

[PSeitz]

@PSeitz What do you mean by minimal vs. uniform API?

I mean defining a single iterator api which is used by all methods, vs minimal api everywhere.