Movement fixes, refactor and unit test suite (#217)

* Add convenience/clarity wrapper for Range initialization

* Test horizontal moves

* Add column jumping tests

* Add failing movement conditions for multi-word moves

* Refactor skip_over_next

* Add complex forward movement unit tests

* Add strict whitespace checks and edge case tests

* Restore formatting

* Remove unused function

* Add empty test case for deletion and fix nth_prev_word_boundary

* Add tests for backward motion

* Refactor word movement

* Address review comments and finish refactoring backwards move

* Finish unit test suite

* Fmt pass

* Fix lint erors

* Clean up diff restoring bad 'cargo fmt' actions

* Simplify movement closures (thanks Pickfire)

* Fmt pass

* Replace index-based movement with iterator based movement, ensuring that each move incurs a single call to the RopeSlice API

* Break down tuple function

* Extract common logic to all movement functions

* Split iterator helpers away into their own module

* WIP reducing clones

* Operate on spans

* WIP simplifying iterators

* Simplify motion helpers

* Fix iterator

* Fix all unit tests

* Refactor and simplify

* Simplify fold

1 files changed, 0 insertions, 68 deletions

diff --git a/helix-core/src/words.rs b/helix-core/src/words.rs
deleted file mode 100644
index 7ecdacba..00000000
--- a/helix-core/src/words.rs
+++ /dev/null
@@ -1,68 +0,0 @@
-use crate::movement::{categorize, is_punctuation, is_word, skip_over_prev};
-use ropey::RopeSlice;
-
-#[must_use]
-pub fn nth_prev_word_boundary(slice: RopeSlice, mut char_idx: usize, count: usize) -> usize {
-    let mut with_end = false;
-
-    for _ in 0..count {
-        if char_idx == 0 {
-            break;
-        }
-
-        // return if not skip while?
-        skip_over_prev(slice, &mut char_idx, |ch| ch == '\n');
-
-        with_end = skip_over_prev(slice, &mut char_idx, char::is_whitespace);
-
-        // refetch
-        let ch = slice.char(char_idx);
-
-        if is_word(ch) {
-            with_end = skip_over_prev(slice, &mut char_idx, is_word);
-        } else if is_punctuation(ch) {
-            with_end = skip_over_prev(slice, &mut char_idx, is_punctuation);
-        }
-    }
-
-    if with_end || char_idx == 0 {
-        char_idx
-    } else {
-        char_idx + 1
-    }
-}
-
-#[test]
-fn different_prev_word_boundary() {
-    use ropey::Rope;
-    let t = |x, y| {
-        let text = Rope::from(x);
-        let out = nth_prev_word_boundary(text.slice(..), text.len_chars().saturating_sub(1), 1);
-        assert_eq!(text.slice(..out), y, r#"from "{}""#, x);
-    };
-    t("abcd\nefg\nwrs", "abcd\nefg\n");
-    t("abcd\nefg\n", "abcd\n");
-    t("abcd\n", "");
-    t("hello, world!", "hello, world");
-    t("hello, world", "hello, ");
-    t("hello, ", "hello");
-    t("hello", "");
-    t(",", "");
-    t("こんにちは、世界！", "こんにちは、世界");
-    t("こんにちは、世界", "こんにちは、");
-    t("こんにちは、", "こんにちは");
-    t("こんにちは", "");
-    t("この世界。", "この世界");
-    t("この世界", "");
-    t("お前はもう死んでいる", "");
-    t("その300円です", ""); // TODO: should stop at 300
-    t("唱k", ""); // TODO: should stop at 唱
-    t("，", "");
-    t("1 + 1 = 2", "1 + 1 = ");
-    t("1 + 1 =", "1 + 1 ");
-    t("1 + 1", "1 + ");
-    t("1 + ", "1 ");
-    t("1 ", "");
-    t("1+1=2", "1+1=");
-    t("", "");
-}