Merge pull request #107 from dermetfan/prefix

return length and width from utils::prefix(_length)

src/printer.rs

@@ -9,7 +9,7 @@ use std::rc::Rc;
 use theme::{BorderStyle, ColorStyle, Effect, Theme};
 use unicode_segmentation::UnicodeSegmentation;
 
-use utils::prefix_length;
+use utils::prefix;
 use vec::Vec2;
 
 /// Convenient interface to draw on a subset of the screen.
@@ -73,7 +73,7 @@ impl<'a> Printer<'a> {
         let room = self.size.x - p.x;
         // We want the number of CHARACTERS, not bytes.
         // (Actually we want the "width" of the string, see unicode-width)
-        let prefix_len = prefix_length(text.graphemes(true), room, "");
+        let prefix_len = prefix(text.graphemes(true), room, "").length;
         let text = &text[..prefix_len];
 
         let p = p + self.offset;

src/utils/lines_iterator.rs

@@ -3,7 +3,7 @@
 use With;
 use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
-use utils::prefix_length;
+use utils::prefix;
 
 /// Generates rows of text in constrained width.
 ///
@@ -119,11 +119,11 @@ impl<'a> Iterator for LinesIterator<'a> {
 
         // First attempt: only break on spaces.
         let prefix_length =
-            match prefix_length(content.split(' '), allowed_width, " ") {
+            match prefix(content.split(' '), allowed_width, " ").length {
                 // If this fail, fallback: only break on graphemes.
                 // There's no whitespace to skip there.
                 // And don't reserve the white space anymore.
-                0 => prefix_length(content.graphemes(true), self.width, ""),
+                0 => prefix(content.graphemes(true), self.width, "").length,
                 other => {
                     // If it works, advance the cursor by 1
                     // to jump the whitespace.

src/utils/mod.rs

@@ -9,7 +9,15 @@ mod reader;
 pub use self::lines_iterator::{LinesIterator, Row};
 pub use self::reader::ProgressReader;
 
-/// Computes the length of a prefix that fits in the given `width`.
+/// The length and width of a part of a string.
+pub struct Prefix {
+    /// The length (in bytes) of the string.
+    pub length: usize,
+    /// The unicode-width of the string.
+    pub width: usize
+}
+
+/// Computes the length (number of bytes) and width of a prefix that fits in the given `width`.
 ///
 /// Takes non-breakable elements from `iter`, while keeping the
 /// string width under `width` (and adding the length of `delimiter`
@@ -26,15 +34,15 @@ pub use self::reader::ProgressReader;
 /// extern crate unicode_segmentation;
 /// use unicode_segmentation::UnicodeSegmentation;
 ///
-/// # use cursive::utils::prefix_length;
+/// # use cursive::utils::prefix;
 /// # fn main() {
 /// let my_text = "blah...";
 /// // This returns the number of bytes for a prefix of `my_text` that
 /// // fits within 5 cells.
-/// prefix_length(my_text.graphemes(true), 5, "");
+/// prefix(my_text.graphemes(true), 5, "");
 /// # }
 /// ```
-pub fn prefix_length<'a, I>(iter: I, available_width: usize, delimiter: &str) -> usize
+pub fn prefix<'a, I>(iter: I, available_width: usize, delimiter: &str) -> Prefix
     where I: Iterator<Item = &'a str>
 {
     let delimiter_width = delimiter.width();
@@ -58,10 +66,15 @@ pub fn prefix_length<'a, I>(iter: I, available_width: usize, delimiter: &str) ->
 
     // We counted delimiter once too many times,
     // but only if the iterator was non empty.
-    if sum == 0 { sum } else { sum - delimiter_len }
+    let length = if sum == 0 { sum } else { sum - delimiter_len };
+
+    Prefix {
+        length: length,
+        width: current_width
+    }
 }
 
-/// Computes the length of a suffix that fits in the given `width`.
+/// Computes the length (number of bytes) and width of a suffix that fits in the given `width`.
 ///
 /// Doesn't break inside elements returned by `iter`.
 ///
@@ -69,15 +82,15 @@ pub fn prefix_length<'a, I>(iter: I, available_width: usize, delimiter: &str) ->
 /// suffix from `text` that fits in `width`.
 ///
 /// This is a shortcut for `prefix_length(iter.rev(), width, delimiter)`
-pub fn suffix_length<'a, I>(iter: I, width: usize, delimiter: &str) -> usize
+pub fn suffix<'a, I>(iter: I, width: usize, delimiter: &str) -> Prefix
     where I: DoubleEndedIterator<Item = &'a str>
 {
-    prefix_length(iter.rev(), width, delimiter)
+    prefix(iter.rev(), width, delimiter)
 }
 
-/// Computes the length of a suffix that fits in the given `width`.
+/// Computes the length (number of bytes) and width of a suffix that fits in the given `width`.
 ///
 /// Breaks between any two graphemes.
-pub fn simple_suffix_length(text: &str, width: usize) -> usize {
+pub fn simple_suffix(text: &str, width: usize) -> Prefix {
-    suffix_length(text.graphemes(true), width, "")
+    suffix(text.graphemes(true), width, "")
 }

src/views/edit_view.rs

@@ -8,7 +8,7 @@ use std::rc::Rc;
 use theme::{ColorStyle, Effect};
 use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
-use utils::simple_suffix_length;
+use utils::simple_suffix;
 use vec::Vec2;
 use view::View;
 
@@ -240,8 +240,8 @@ impl EditView {
             // From the end, count the length until we reach `available`.
             // Then sum the byte lengths.
             let suffix_length =
-                simple_suffix_length(&self.content[self.offset..self.cursor],
+                simple_suffix(&self.content[self.offset..self.cursor],
-                                     available);
+                              available).length;
             self.offset = self.cursor - suffix_length;
             // Make sure the cursor is in view
             assert!(self.cursor >= self.offset);
@@ -250,8 +250,8 @@ impl EditView {
 
         // If we have too much space
         if self.content[self.offset..].width() < self.last_length {
-            let suffix_length = simple_suffix_length(&self.content,
+            let suffix_length = simple_suffix(&self.content,
-                                                     self.last_length - 1);
+                                              self.last_length - 1).length;
             self.offset = self.content.len() - suffix_length;
         }
     }

src/views/text_area.rs

@@ -7,7 +7,7 @@ use odds::vec::VecExt;
 use theme::{ColorStyle, Effect};
 use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
-use utils::{LinesIterator, Row, prefix_length};
+use utils::{LinesIterator, Row, prefix};
 use vec::Vec2;
 use view::{ScrollBase, SizeCache, View};
 
@@ -126,7 +126,7 @@ impl TextArea {
 
         let prev_row = self.rows[row_id - 1];
         let prev_text = &self.content[prev_row.start..prev_row.end];
-        let offset = prefix_length(prev_text.graphemes(true), x, "");
+        let offset = prefix(prev_text.graphemes(true), x, "").length;
         self.cursor = prev_row.start + offset;
     }
 
@@ -139,7 +139,7 @@ impl TextArea {
 
         let next_row = self.rows[row_id + 1];
         let next_text = &self.content[next_row.start..next_row.end];
-        let offset = prefix_length(next_text.graphemes(true), x, "");
+        let offset = prefix(next_text.graphemes(true), x, "").length;
         self.cursor = next_row.start + offset;
     }