From b5021411a84822cb3f1e3aeffad9550dd15bdeb6 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Sun, 16 Sep 2018 12:54:24 +0300
Subject: rename all things

---
 crates/ra_editor/src/line_index.rs | 62 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 crates/ra_editor/src/line_index.rs

(limited to 'crates/ra_editor/src/line_index.rs')

diff --git a/crates/ra_editor/src/line_index.rs b/crates/ra_editor/src/line_index.rs
new file mode 100644
index 000000000..9cd8da3a8
--- /dev/null
+++ b/crates/ra_editor/src/line_index.rs
@@ -0,0 +1,62 @@
+use superslice::Ext;
+use ::TextUnit;
+
+#[derive(Clone, Debug, Hash)]
+pub struct LineIndex {
+    newlines: Vec<TextUnit>,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub struct LineCol {
+    pub line: u32,
+    pub col: TextUnit,
+}
+
+impl LineIndex {
+    pub fn new(text: &str) -> LineIndex {
+        let mut newlines = vec![0.into()];
+        let mut curr = 0.into();
+        for c in text.chars() {
+            curr += TextUnit::of_char(c);
+            if c == '\n' {
+                newlines.push(curr);
+            }
+        }
+        LineIndex { newlines }
+    }
+
+    pub fn line_col(&self, offset: TextUnit) -> LineCol {
+        let line = self.newlines.upper_bound(&offset) - 1;
+        let line_start_offset = self.newlines[line];
+        let col = offset - line_start_offset;
+        return LineCol { line: line as u32, col };
+    }
+
+    pub fn offset(&self, line_col: LineCol) -> TextUnit {
+        //TODO: return Result
+        self.newlines[line_col.line as usize] + line_col.col
+    }
+}
+
+#[test]
+fn test_line_index() {
+    let text = "hello\nworld";
+    let index = LineIndex::new(text);
+    assert_eq!(index.line_col(0.into()), LineCol { line: 0, col: 0.into() });
+    assert_eq!(index.line_col(1.into()), LineCol { line: 0, col: 1.into() });
+    assert_eq!(index.line_col(5.into()), LineCol { line: 0, col: 5.into() });
+    assert_eq!(index.line_col(6.into()), LineCol { line: 1, col: 0.into() });
+    assert_eq!(index.line_col(7.into()), LineCol { line: 1, col: 1.into() });
+    assert_eq!(index.line_col(8.into()), LineCol { line: 1, col: 2.into() });
+    assert_eq!(index.line_col(10.into()), LineCol { line: 1, col: 4.into() });
+    assert_eq!(index.line_col(11.into()), LineCol { line: 1, col: 5.into() });
+    assert_eq!(index.line_col(12.into()), LineCol { line: 1, col: 6.into() });
+
+    let text = "\nhello\nworld";
+    let index = LineIndex::new(text);
+    assert_eq!(index.line_col(0.into()), LineCol { line: 0, col: 0.into() });
+    assert_eq!(index.line_col(1.into()), LineCol { line: 1, col: 0.into() });
+    assert_eq!(index.line_col(2.into()), LineCol { line: 1, col: 1.into() });
+    assert_eq!(index.line_col(6.into()), LineCol { line: 1, col: 5.into() });
+    assert_eq!(index.line_col(7.into()), LineCol { line: 2, col: 0.into() });
+}
-- 
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