From 08ab867b1bfed69c59f56d4beafca1e147e8a38e Mon Sep 17 00:00:00 2001
From: mattwparas <matthewparas2020@u.northwestern.edu>
Date: Fri, 18 Aug 2023 22:02:08 -0700
Subject: [PATCH] indent stuff

---
 helix-core/src/extensions.rs | 136 ++++++++++++++++++++++++++++++++++-
 helix-core/src/indent.rs     |   3 +-
 2 files changed, 135 insertions(+), 4 deletions(-)

diff --git a/helix-core/src/extensions.rs b/helix-core/src/extensions.rs
index c661eb760..9939b5f41 100644
--- a/helix-core/src/extensions.rs
+++ b/helix-core/src/extensions.rs
@@ -1,9 +1,10 @@
 use std::{borrow::Cow, cell::Cell, rc::Rc};
 
 use ropey::iter::Chars;
+use smallvec::SmallVec;
 use steel::{
     gc::unsafe_erased_pointers::CustomReference,
-    rvals::Custom,
+    rvals::{Custom, SteelString},
     steel_vm::{builtin::BuiltInModule, register_fn::RegisterFn, register_fn::RegisterFnBorrowed},
 };
 
@@ -60,7 +61,7 @@ impl<'a> SRopeSlice<'a> {
 
     pub fn slice(&'a self, lower: usize, upper: usize) -> SRopeSlice<'a> {
         SRopeSlice {
-            slice: self.slice.byte_slice(lower..upper),
+            slice: self.slice.slice(lower..upper),
         }
     }
 
@@ -99,6 +100,7 @@ pub fn rope_slice_module() -> BuiltInModule {
 
     // TODO: Note the difficulty of the lifetime params here
     module.register_fn("slice->string", SRopeSlice::to_string);
+    module.register_fn("slice-char->byte", SRopeSlice::char_to_byte);
 
     // module
     // .register_fn("slice-char->byte", SRopeSlice::char_to_byte)
@@ -109,3 +111,133 @@ pub fn rope_slice_module() -> BuiltInModule {
 
     module
 }
+
+#[derive(Clone, Copy, Debug)]
+enum SliceKind {
+    Normal(usize, usize),
+    Byte(usize, usize),
+    Line(usize),
+}
+
+#[derive(Clone)]
+pub struct SteelRopeSlice {
+    text: crate::Rope,
+    ranges: SmallVec<[SliceKind; 5]>,
+}
+
+// #[derive(Clone)]
+// pub struct SteelRopeString {
+//     slice: SteelRopeSlice,
+//     operations: SmallVec<[StringOperation; 5]>,
+// }
+
+// #[derive(Clone)]
+// enum StringOperation {
+//     TrimStart,
+//     StartsWith(SteelString),
+// }
+
+// impl SteelRopeString {
+//     pub fn evaluate(&self) -> SteelVal {
+//         todo!()
+//     }
+// }
+
+impl Custom for SteelRopeSlice {}
+// impl Custom for SteelRopeString {}
+
+impl SteelRopeSlice {
+    pub fn from_string(string: SteelString) -> Self {
+        Self {
+            text: crate::Rope::from_str(string.as_str()),
+            ranges: SmallVec::default(),
+        }
+    }
+
+    pub fn new(rope: crate::Rope) -> Self {
+        Self {
+            text: rope,
+            ranges: SmallVec::default(),
+        }
+    }
+
+    fn to_slice(&self) -> crate::RopeSlice<'_> {
+        let mut slice = self.text.slice(..);
+
+        for range in &self.ranges {
+            match range {
+                SliceKind::Normal(l, r) => slice = slice.slice(l..r),
+                SliceKind::Byte(l, r) => slice = slice.byte_slice(l..r),
+                SliceKind::Line(index) => slice = slice.line(*index),
+            }
+        }
+
+        slice
+    }
+
+    pub fn slice(mut self, lower: usize, upper: usize) -> Self {
+        self.ranges.push(SliceKind::Normal(lower, upper));
+        self
+    }
+
+    pub fn char_to_byte(&self, pos: usize) -> usize {
+        self.to_slice().char_to_byte(pos)
+    }
+
+    pub fn byte_slice(mut self, lower: usize, upper: usize) -> Self {
+        self.ranges.push(SliceKind::Byte(lower, upper));
+        self
+    }
+
+    pub fn line(mut self, cursor: usize) -> Self {
+        self.ranges.push(SliceKind::Line(cursor));
+        self
+    }
+
+    pub fn to_string(&self) -> String {
+        self.to_slice().to_string()
+    }
+
+    pub fn len_chars(&self) -> usize {
+        self.to_slice().len_chars()
+    }
+
+    pub fn get_char(&self, index: usize) -> Option<char> {
+        self.to_slice().get_char(index)
+    }
+
+    pub fn len_lines(&self) -> usize {
+        self.to_slice().len_lines()
+    }
+
+    pub fn trimmed_starts_with(&self, pat: SteelString) -> bool {
+        let maybe_owned = Cow::from(self.to_slice());
+
+        maybe_owned.trim_start().starts_with(pat.as_str())
+    }
+
+    // pub fn as_cow(&'a self) -> SRopeSliceCowStr<'a> {
+    //     SRopeSliceCowStr(std::borrow::Cow::from(self.slice))
+    // }
+}
+
+pub fn rope_module() -> BuiltInModule {
+    let mut module = BuiltInModule::new("helix/core/text");
+
+    module
+        .register_fn("string->slice", SteelRopeSlice::from_string)
+        .register_fn("slice->slice", SteelRopeSlice::slice)
+        .register_fn("slice-char->byte", SteelRopeSlice::char_to_byte)
+        .register_fn("slice->byte-slice", SteelRopeSlice::byte_slice)
+        .register_fn("slice->line", SteelRopeSlice::line)
+        .register_fn("slice->string", SteelRopeSlice::to_string)
+        .register_fn("slice-len-chars", SteelRopeSlice::len_chars)
+        .register_fn("slice-char-ref", SteelRopeSlice::get_char)
+        .register_fn("slice-len-lines", SteelRopeSlice::len_lines)
+        .register_fn(
+            "slice-trim-and-starts-with?",
+            SteelRopeSlice::trimmed_starts_with,
+        );
+
+    module
+}
diff --git a/helix-core/src/indent.rs b/helix-core/src/indent.rs
index 59f9e7125..8da8c02aa 100644
--- a/helix-core/src/indent.rs
+++ b/helix-core/src/indent.rs
@@ -814,8 +814,7 @@ pub fn custom_indent_for_newline(
 
                                 let offset = line.len_chars() - index;
 
-                                let mut char_iter_from_paren =
-                                    line.chars_at(line.len_chars() - index).enumerate();
+                                let mut char_iter_from_paren = line.chars_at(offset).enumerate();
 
                                 let end;