Allow any indent size from 1 to 16

helix-core/src/indent.rs

@@ -19,6 +19,9 @@ pub enum IndentStyle {
     Spaces(u8),
 }
 
+// 16 spaces
+const INDENTS: &str = "                ";
+
 impl IndentStyle {
     /// Creates an `IndentStyle` from an indentation string.
     ///
@@ -27,7 +30,7 @@ impl IndentStyle {
     #[inline]
     pub fn from_str(indent: &str) -> Self {
         // XXX: do we care about validating the input more than this?  Probably not...?
-        debug_assert!(!indent.is_empty() && indent.len() <= 8);
+        debug_assert!(!indent.is_empty() && indent.len() <= 256);
 
         if indent.starts_with(' ') {
             IndentStyle::Spaces(indent.len() as u8)
@@ -40,20 +43,13 @@ impl IndentStyle {
     pub fn as_str(&self) -> &'static str {
         match *self {
             IndentStyle::Tabs => "\t",
-            IndentStyle::Spaces(1) => " ",
-            IndentStyle::Spaces(2) => "  ",
-            IndentStyle::Spaces(3) => "   ",
-            IndentStyle::Spaces(4) => "    ",
-            IndentStyle::Spaces(5) => "     ",
-            IndentStyle::Spaces(6) => "      ",
-            IndentStyle::Spaces(7) => "       ",
-            IndentStyle::Spaces(8) => "        ",
-
+            IndentStyle::Spaces(n) if n <= 16 && n >= 1 => &INDENTS[0..n as usize],
             // Unsupported indentation style.  This should never happen,
-            // but just in case fall back to two spaces.
+            // but just in case fall back to 16 spaces (the largest we support).
             IndentStyle::Spaces(n) => {
-                debug_assert!(n > 0 && n <= 8); // Always triggers. `debug_panic!()` wanted.
-                "  "
+                debug_assert!(n > 0 && n <= 16); // Always triggers. `debug_panic!()` wanted.
+                let closest_n = n.clamp(1, 16);
+                &INDENTS[0..closest_n as usize]
             }
         }
     }
@@ -75,9 +71,9 @@ pub fn auto_detect_indent_style(document_text: &Rope) -> Option<IndentStyle> {
     // Build a histogram of the indentation *increases* between
     // subsequent lines, ignoring lines that are all whitespace.
     //
-    // Index 0 is for tabs, the rest are 1-8 spaces.
-    let histogram: [usize; 9] = {
-        let mut histogram = [0; 9];
+    // Index 0 is for tabs, the rest are 1-16 spaces.
+    let histogram: [usize; 17] = {
+        let mut histogram = [0; 17];
         let mut prev_line_is_tabs = false;
         let mut prev_line_leading_count = 0usize;
 
@@ -136,7 +132,7 @@ pub fn auto_detect_indent_style(document_text: &Rope) -> Option<IndentStyle> {
                     histogram[0] += 1;
                 } else {
                     let amount = leading_count - prev_line_leading_count;
-                    if amount <= 8 {
+                    if amount <= 16 {
                         histogram[amount] += 1;
                     }
                 }
@@ -797,4 +793,20 @@ mod test {
             3
         );
     }
+
+    #[test]
+    fn test_large_indent_level() {
+        let tab_width = 16;
+        let indent_width = 16;
+        let line = Rope::from("                fn new"); // 16 spaces
+        assert_eq!(
+            indent_level_for_line(line.slice(..), tab_width, indent_width),
+            1
+        );
+        let line = Rope::from("                                fn new"); // 32 spaces
+        assert_eq!(
+            indent_level_for_line(line.slice(..), tab_width, indent_width),
+            2
+        );
+    }
 }