Optimizations and cleanup

src/byte_string.rs

@@ -349,6 +349,173 @@ pub(crate) fn translate_with_style_lower_and_upper_suffixes (
         return;
     }
 
+    let mut global_index: usize = 0;
+    loop {
+        //Copies characters in-between words
+        //TODO this could probably be optimized with vector instructions
+        {
+            let mut start_of_in_between_words_index: usize = global_index;//Inclusive
+            loop {
+                if english[global_index].is_ascii_alphabetic() {//Start of a word
+                    break;
+                }
+
+                global_index += 1;
+                if global_index == english.len() {
+                    //Copy all of the characters so far (all that remain) and return
+                    let remaining_characters_slice = &english[start_of_in_between_words_index..];
+                    pig_latin_string.extend_from_slice(remaining_characters_slice);
+                    return;
+                }
+            }
+            //Copy the characters in-between words as-is
+            let in_between_words_characters_slice = &english[start_of_in_between_words_index..global_index];
+            pig_latin_string.extend_from_slice(in_between_words_characters_slice);
+
+            //At this point, global_index contains the index to the start of the word to translate
+        }
+
+        //Translates the current word
+        {
+            let word_start_index = global_index;
+            let first_letter = english[word_start_index];
+            global_index += 1;
+
+            if (global_index == english.len()) || (!english[global_index].is_ascii_alphabetic()) {//The word is only one letter long (special case)
+                //Push the letter and add the lowercase special suffix (even if the letter is uppercase)
+                pig_latin_string.push(first_letter);
+                pig_latin_string.extend_from_slice(special_case_suffix_lower);
+            } else if is_vowel(first_letter) {//The word is longer than a letter and starts with a vowel (special case)
+                //As a heuristic, we consider Y to be a vowel when it is not at the start of the word
+
+                //Get the slice containing the whole word
+                let slice_to_search_for_end = &english[global_index..];
+                let word_slice: &[u8];
+                if let Some(found_end_of_word_index) = slice_to_search_for_end.iter().position(|&x| !x.is_ascii_alphabetic()) {//We found a non-letter that ends the word
+                    global_index += found_end_of_word_index;
+                    word_slice = &english[word_start_index..global_index];
+                } else {//The string ended
+                    global_index = english.len();
+                    word_slice = slice_to_search_for_end;
+                }
+
+                //Translate the word and push it
+                pig_latin_string.extend_from_slice(word_slice);
+                if fast_is_ascii_uppercase(english[word_start_index + 1]) {//As a heuristic, we consider the word to be uppercase if the second letter is
+                    pig_latin_string.extend_from_slice(special_case_suffix_upper);
+                } else {//Word is entirely lowercase, or its first letter is uppercase only
+                    pig_latin_string.extend_from_slice(special_case_suffix_lower);
+                }
+            } else {//The word is longer than a letter and doesn't start with a vowel
+                //Find the first vowel; we assume the word actually has a vowel in it
+                let first_vowel_index: usize;
+                let slice_to_search_for_vowel = &english[global_index..];
+                if let Some(first_vowel_of_word_index) = slice_to_search_for_vowel.iter().position(|&x| { is_vowel(x) || is_y(x) }) {//As a heuristic, we consider Y to be a vowel when it is not at the start of the word
+                    global_index += first_vowel_of_word_index;
+                } else {//This string ended and we never found a vowel
+                    return;//Just give up
+                }
+                first_vowel_index = global_index;
+
+                //Find the end of the word
+                let word_end_index: usize;
+                let slice_to_search_for_end = &english[global_index..];
+                if let Some(end_of_word_index) = slice_to_search_for_end.iter().position(|&x| !x.is_ascii_alphabetic()) {//We found a non-letter that ends the word
+                    global_index += end_of_word_index;
+                } else {//The string ended
+                    global_index = english.len();
+                }
+                word_end_index = global_index;
+
+                //Translate the word
+                //TODO improve code reuse here
+                if fast_is_ascii_uppercase(first_letter) {//Check if the first letter is uppercase
+                    if fast_is_ascii_uppercase(english[word_start_index + 1]) {//As a heuristic, we consider the word to be uppercase if the second letter is
+                        //Push the vowel and all letters after it
+                        let vowel_to_end_slice = &english[first_vowel_index..word_end_index];
+                        pig_latin_string.extend_from_slice(vowel_to_end_slice);
+
+                        //Push the starting consonants
+                        let start_to_vowel_slice = &english[word_start_index..first_vowel_index];
+                        pig_latin_string.extend_from_slice(start_to_vowel_slice);
+
+                        //Push the normal suffix (uppercase)
+                        pig_latin_string.extend_from_slice(suffix_upper);
+                    } else {//Word starts with an uppercase letter, but is otherwise lowercase
+                        //Push the vowel, matching the starting case of the original word
+                        pig_latin_string.push(fast_to_ascii_uppercase(english[first_vowel_index]));
+
+                        //Push all letters after the vowel
+                        let after_vowel_slice = &english[(first_vowel_index + 1)..word_end_index];
+                        pig_latin_string.extend_from_slice(after_vowel_slice);
+
+                        //Push the first starting consonant, which should be lowercase now
+                        pig_latin_string.push(fast_to_ascii_lowercase(english[word_start_index]));
+
+                        //Push the remaining starting consonants
+                        let after_start_to_vowel_slice = &english[(word_start_index + 1)..first_vowel_index];
+                        pig_latin_string.extend_from_slice(after_start_to_vowel_slice);
+
+                        //Push the normal suffix
+                        pig_latin_string.extend_from_slice(suffix_lower);
+                    }
+                } else {//Word is entirely lowercase
+                    //Push the vowel and all letters after it
+                    let vowel_to_end_slice = &english[first_vowel_index..word_end_index];
+                    pig_latin_string.extend_from_slice(vowel_to_end_slice);
+
+                    //Push the starting consonants
+                    let start_to_vowel_slice = &english[word_start_index..first_vowel_index];
+                    pig_latin_string.extend_from_slice(start_to_vowel_slice);
+
+                    //Push the normal suffix (lowercase)
+                    pig_latin_string.extend_from_slice(suffix_lower);
+                }
+            }
+
+            //Don't go on if we reached the end of the string during the word
+            if global_index == english.len() {
+                return;
+            }
+
+            //At this point, global_index contains the index to the next character to check
+        }
+
+        //Copies contraction suffixes, if present
+        if english[global_index] == b'\'' {//TODO if this is true we can also skip the regular inter-word loop on the next iteration
+            let mut start_of_contraction_suffix_index: usize = global_index;//Inclusive
+            global_index += 1;//We skip over the apostrophe for the loop below, but we still want to copy it in the end
+            loop {
+                if global_index == english.len() {
+                    //Copy all of the characters so far (all that remain) and return
+                    let remaining_characters_slice = &english[start_of_contraction_suffix_index..];
+                    pig_latin_string.extend_from_slice(remaining_characters_slice);
+                    return;
+                }
+
+                if !english[global_index].is_ascii_alphabetic() {//End of the contraction suffix
+                    break;
+                }
+
+                global_index += 1;
+            }
+            //Copy the contraction suffix as-is
+            let contraction_suffix_slice = &english[start_of_contraction_suffix_index..global_index];
+            pig_latin_string.extend_from_slice(contraction_suffix_slice);
+        }
+    }
+}
+
+//Avoids the overhead of having to convert suffixes to uppercase for the standard translation functions at runtime
+pub(crate) fn translate_with_style_lower_and_upper_suffixes_old (
+    english: &[u8],
+    suffix_lower: &[u8], special_case_suffix_lower: &[u8], suffix_upper: &[u8], special_case_suffix_upper: &[u8],
+    pig_latin_string: &mut Vec::<u8>
+) {
+    if english.is_empty() {
+        return;
+    }
+
     //TODO merge the word and the generic text function into one function to allow for optimizations with certain things
     //TODO do an SSE/AVX optimized version of this