rust: finish up EGC type safe wrapping.

rust/src/cells.rs

@@ -59,7 +59,7 @@
 
 use crate as ffi;
 use ffi::types::{
-    AlphaBits, Channel, ChannelPair, Color, IntResult, PaletteIndex, StyleMask,
+    AlphaBits, Channel, ChannelPair, CellGcluster, Color, EGC, IntResult, PaletteIndex, StyleMask,
 };
 use ffi::{cell, ncplane};
 
@@ -261,8 +261,10 @@ pub fn cell_wide_left_p(cell: &cell) -> bool {
 /// result is not tied to the ncplane, and persists across erases / destruction.
 // TODO: TEST
 #[inline]
-pub fn cell_strdup(plane: &ncplane, cell: &cell) -> *mut i8 {
-    unsafe { libc::strdup(ffi::cell_extended_gcluster(plane, cell)) }
+pub fn cell_strdup(plane: &ncplane, cell: &cell) -> EGC {
+    unsafe {
+        core::char::from_u32_unchecked(libc::strdup(ffi::cell_extended_gcluster(plane, cell)) as i32 as u32)
+    }
 }
 
 /// Extract the three elements of a cell.
@@ -273,7 +275,7 @@ pub fn cell_extract(
     cell: &cell,
     stylemask: &mut StyleMask,
     channels: &mut ChannelPair,
-) -> *mut i8 {
+) -> EGC {
     if *stylemask != 0 {
         *stylemask = cell.stylemask;
     }
@@ -307,12 +309,12 @@ pub fn cellcmp(plane1: &ncplane, cell1: &cell, plane2: &ncplane, cell2: &cell) -
 // TODO: TEST
 // NOTE: remove casting for CELL_WIEDASIAN_MASK when fixed: https://github.com/rust-lang/rust-bindgen/issues/1875
 #[inline]
-pub fn cell_load_simple(plane: &mut ncplane, cell: &mut cell, ch: char) -> i32 {
+pub fn cell_load_simple(plane: &mut ncplane, cell: &mut cell, ch: EGC) -> i32 {
     unsafe {
         ffi::cell_release(plane, cell);
     }
     cell.channels &= !(ffi::CELL_WIDEASIAN_MASK as u64 | ffi::CELL_NOBACKGROUND_MASK);
-    cell.gcluster = ch as u32;
+    cell.gcluster = ch as CellGcluster;
     1
 }
 

rust/src/plane.rs

@@ -142,7 +142,7 @@ use core::ptr::null_mut;
 use cstr_core::CString;
 
 use crate as ffi;
-use ffi::types::{AlphaBits, Channel, ChannelPair, Color, EGCBackstop, IntResult, StyleMask};
+use ffi::types::{AlphaBits, Channel, ChannelPair, Color, EGC, EGCBackstop, IntResult, StyleMask};
 use ffi::{cell, ncalign_e, ncplane};
 
 /// Return the column at which 'cols' columns ought start in order to be aligned
@@ -470,7 +470,7 @@ pub fn ncplane_putc(plane: &mut ncplane, cell: &cell) -> IntResult {
 /// Call ncplane_putsimple_yx() at the current cursor location.
 // TODO: TEST
 #[inline]
-pub fn ncplane_putsimple(plane: &mut ncplane, ch: char) -> IntResult {
+pub fn ncplane_putsimple(plane: &mut ncplane, ch: EGC) -> IntResult {
     ffi::ncplane_putsimple_yx(plane, -1, -1, ch)
 }
 
@@ -484,12 +484,12 @@ pub fn ncplane_putegc(plane: &mut ncplane, gcluster: i8, sbytes: &mut i32) -> In
 /// Replace the EGC underneath us, but retain the styling. The current styling
 /// of the plane will not be changed.
 ///
-/// Replace the cell at the specified coordinates with the provided 7-bit char
-/// 'ch'. Advance the cursor by 1. On success, returns 1. On failure, returns -1.
-/// This works whether the underlying char is signed or unsigned.
+/// Replace the cell at the specified coordinates with the provided 7-bit char 'ch'.
+/// Advance the cursor by 1. On success, returns 1. On failure, returns -1.
+///
 // TODO: TEST
 #[inline]
-pub fn ncplane_putsimple_yx(plane: &mut ncplane, y: i32, x: i32, ch: char) -> IntResult {
+pub fn ncplane_putsimple_yx(plane: &mut ncplane, y: i32, x: i32, ch: EGC) -> IntResult {
     let newcell = cell_initializer![ch, unsafe { ffi::ncplane_attr(plane) }, unsafe {
         ffi::ncplane_channels(plane)
     }];

rust/src/types.rs

@@ -140,7 +140,7 @@ pub type Pixel = u32;
 
 /// EGC (Extended Grapheme Cluster)
 ///
-/// These 32 bits, together with the associated plane's associated egcpool,
+/// This 32 bit char, together with the associated plane's associated egcpool,
 /// completely define this cell's EGC. Unless the EGC requires more than four
 /// bytes to encode as UTF-8, it will be inlined here:
 ///
@@ -174,9 +174,9 @@ pub type Pixel = u32;
 /// type in C: gcluster (uint32_t)
 ///
 // WIP towards a safe abstraction for Cell & functions receiving
-// pub type EGC = u32;
-// pub type EGC = char;
-// pub type EGC<'a> = &'a[u8];
+pub type EGC = char;
+// pub type EGCPool<'a> = &'a[u8];
+pub type CellGcluster = u32; // the type cell.gcluster expects the EGB to be
 
 /// EGC BackStop
 ///