added InvalidSelection error, moved all selection stuff to separate file

editor/editor-ideas.md

@@ -51,6 +51,7 @@ These are potentially inspirational resources for the editor's design.
     * [Blueprints](https://docs.unrealengine.com/en-US/Engine/Blueprints/index.html) visual scripting (not suggesting visual scripting for Roc)
 
 * [Live Programing](https://www.microsoft.com/en-us/research/project/live-programming/?from=http%3A%2F%2Fresearch.microsoft.com%2Fen-us%2Fprojects%2Fliveprogramming%2Ftypography.aspx#!publications) by [Microsoft Research] it contains many interesting research papers.
+* When refactoring; cutting and pasting code to a new file should automatically add imports to the new file and delete them from the old file. 
 
 ### Non-Code Related Inspiration
 

editor/src/error.rs

@@ -19,6 +19,14 @@ pub enum EdError {
         vec_len: usize,
         backtrace: Backtrace 
     },
+    #[snafu(display(
+        "InvalidSelection: {}",
+        err_msg
+    ))]
+    InvalidSelection { 
+        err_msg: String,
+        backtrace: Backtrace 
+    },
 }
 
 pub type EdResult<T, E = EdError> = std::result::Result<T, E>;

editor/src/lib.rs

@@ -12,7 +12,7 @@ use crate::buffer::create_rect_buffers;
 use crate::text::{build_glyph_brush, Text};
 use crate::vertex::Vertex;
 use crate::rect::{Rect};
-use crate::error::{EdResult, print_err};
+use crate::error::{print_err};
 use ortho::{init_ortho, update_ortho_buffer, OrthoResources};
 use std::error::Error;
 use std::io;
@@ -20,7 +20,7 @@ use std::path::Path;
 use winit::event;
 use winit::event::{Event, ModifiersState};
 use winit::event_loop::ControlFlow;
-use vec_result::{get_res};
+use selection::{create_selection_rects, RawSelection};
 
 pub mod ast;
 mod buffer;
@@ -39,6 +39,7 @@ mod vertex;
 mod colors;
 pub mod error;
 mod vec_result;
+mod selection;
 
 /// The editor is actually launched from the CLI if you pass it zero arguments,
 /// or if you provide it 1 or more files or directories to open on launch.
@@ -206,7 +207,14 @@ fn run_event_loop() -> Result<(), Box<dyn Error>> {
                     &mut glyph_brush,
                 );
 
-                let selection_rects_res = create_selection_rects(1, 5, 4, 2, &glyph_bounds_rects);
+                let selection =
+                    RawSelection {
+                        start_line_indx: 1,
+                        pos_in_start_line: 3,
+                        stop_line_indx: 4,
+                        pos_in_stop_line: 5,
+                    };
+                let selection_rects_res = create_selection_rects(selection, &glyph_bounds_rects);
 
                 match selection_rects_res {
                     Ok(selection_rects) => 
@@ -269,146 +277,6 @@ fn run_event_loop() -> Result<(), Box<dyn Error>> {
 }
 
 
-fn create_selection_rects(
-    start_line_indx: usize,
-    pos_in_start_line: usize,
-    stop_line_indx: usize,
-    pos_in_stop_line: usize,
-    glyph_bound_rects: &Vec<Vec<Rect>>
-)  -> EdResult<Vec<Rect>> {
-    //TODO assert start_line <= stop_line, if start_line == stop_line => pos_in_start_line <= pos_in_stop_line
-
-    let mut all_rects = Vec::new();
-
-    if start_line_indx == stop_line_indx {
-        let start_glyph_rect = 
-            get_res(
-                pos_in_start_line,
-                get_res(start_line_indx, glyph_bound_rects)?,
-            )?;
-
-        let stop_glyph_rect = 
-            get_res(
-                pos_in_stop_line,
-                get_res(stop_line_indx, glyph_bound_rects)?
-            )?;
-
-        let top_left_coords =
-            start_glyph_rect.top_left_coords;
-
-        let height = start_glyph_rect.height;
-        let width = (stop_glyph_rect.top_left_coords.x - start_glyph_rect.top_left_coords.x) + stop_glyph_rect.width;
-
-        all_rects.push(
-            Rect {
-                top_left_coords,
-                width,
-                height,
-                color: colors::WHITE
-            }
-        );
-
-        Ok(all_rects)
-    } else {
-        // first line
-        let start_line = get_res(start_line_indx, glyph_bound_rects)?;
-
-        let start_glyph_rect = 
-            get_res(
-                pos_in_start_line,
-                start_line
-            )?;
-
-        let start_line_last_glyph_rect = 
-            get_res(
-                start_line.len() - 1,
-                start_line
-            )?;
-
-        let top_left_coords =
-            start_glyph_rect.top_left_coords;
-
-        let height = start_glyph_rect.height;
-        let width = (start_line_last_glyph_rect.top_left_coords.x - start_glyph_rect.top_left_coords.x) + start_line_last_glyph_rect.width;
-
-        all_rects.push(
-            Rect {
-                top_left_coords,
-                width,
-                height,
-                color: colors::WHITE
-            }
-        );
-
-        //middle lines
-        let nr_mid_lines = (stop_line_indx - start_line_indx) - 1;
-        let first_mid_line = start_line_indx + 1;
-
-        for i in first_mid_line..(first_mid_line + nr_mid_lines)  {
-            let mid_line = get_res(i, glyph_bound_rects)?;
-
-            let mid_line_first_glyph_rect = 
-                get_res(
-                    0,
-                    mid_line
-                )?;
-
-            let mid_line_last_glyph_rect = 
-                get_res(
-                    mid_line.len() - 1,
-                    mid_line
-                )?;
-
-            let top_left_coords =
-                mid_line_first_glyph_rect.top_left_coords;
-
-            let height = mid_line_first_glyph_rect.height;
-            let width = (mid_line_last_glyph_rect.top_left_coords.x - mid_line_first_glyph_rect.top_left_coords.x) + mid_line_last_glyph_rect.width;
-
-            all_rects.push(
-                Rect {
-                    top_left_coords,
-                    width,
-                    height,
-                    color: colors::WHITE
-                }
-            );
-        }
-
-        //last line
-        let stop_line = get_res(stop_line_indx, glyph_bound_rects)?;
-
-        let stop_line_first_glyph_rect = 
-        get_res(
-            0,
-            stop_line
-        )?;
-
-        let stop_glyph_rect = 
-            get_res(
-                pos_in_stop_line,
-                stop_line
-            )?;
-
-        let top_left_coords =
-            stop_line_first_glyph_rect.top_left_coords;
-
-        let height = stop_glyph_rect.height;
-        let width = (stop_glyph_rect.top_left_coords.x - stop_line_first_glyph_rect.top_left_coords.x) + stop_glyph_rect.width;
-
-        all_rects.push(
-            Rect {
-                top_left_coords,
-                width,
-                height,
-                color: colors::WHITE
-            }
-        );
-        
-        Ok(all_rects)
-    }
-}
-
 fn make_rect_pipeline(
     gpu_device: &wgpu::Device,
     swap_chain_descr: &wgpu::SwapChainDescriptor,

editor/src/selection.rs

@@ -0,0 +1,189 @@
+
+use crate::rect::{Rect};
+use crate::vec_result::{get_res};
+use crate::error::{EdResult, InvalidSelection};
+use crate::colors;
+use snafu::ensure;
+
+pub struct RawSelection {
+    pub start_line_indx: usize,
+    pub pos_in_start_line: usize,
+    pub stop_line_indx: usize,
+    pub pos_in_stop_line: usize,
+}
+
+//using the "parse don't validate" pattern
+struct ValidSelection {
+    selection: RawSelection
+}
+
+fn validate_selection( selection: RawSelection) -> EdResult<ValidSelection> {
+    let RawSelection {start_line_indx, pos_in_start_line, stop_line_indx, pos_in_stop_line} = selection;
+
+    ensure!(
+        start_line_indx <= stop_line_indx,
+        InvalidSelection { err_msg: 
+            format!(
+                "start_line_indx ({}) should be smaller than or equal to stop_line_indx ({})",
+                start_line_indx,
+                stop_line_indx 
+            )
+        }
+    );
+
+    ensure!(
+        !(start_line_indx == stop_line_indx && pos_in_start_line > pos_in_stop_line),
+        InvalidSelection { err_msg: 
+            format!(
+                "pos_in_start_line ({}) should be smaller than or equal to pos_in_stop_line ({}) when start_line_indx equals stop_line_indx",
+                pos_in_start_line,
+                pos_in_stop_line
+            )
+        }
+    );
+
+    Ok(
+        ValidSelection {
+            selection
+        }
+    )
+}
+
+
+pub fn create_selection_rects(
+    raw_sel: RawSelection,
+    glyph_bound_rects: &Vec<Vec<Rect>>
+)  -> EdResult<Vec<Rect>> {
+    let valid_sel = validate_selection(raw_sel)?;
+    let RawSelection {start_line_indx, pos_in_start_line, stop_line_indx, pos_in_stop_line} = valid_sel.selection;
+
+    let mut all_rects = Vec::new();
+
+    if start_line_indx == stop_line_indx {
+        let start_glyph_rect = 
+            get_res(
+                pos_in_start_line,
+                get_res(start_line_indx, glyph_bound_rects)?,
+            )?;
+
+        let stop_glyph_rect = 
+            get_res(
+                pos_in_stop_line,
+                get_res(stop_line_indx, glyph_bound_rects)?
+            )?;
+
+        let top_left_coords =
+            start_glyph_rect.top_left_coords;
+
+        let height = start_glyph_rect.height;
+        let width = (stop_glyph_rect.top_left_coords.x - start_glyph_rect.top_left_coords.x) + stop_glyph_rect.width;
+
+        all_rects.push(
+            Rect {
+                top_left_coords,
+                width,
+                height,
+                color: colors::WHITE
+            }
+        );
+
+        Ok(all_rects)
+    } else {
+        // first line
+        let start_line = get_res(start_line_indx, glyph_bound_rects)?;
+
+        let start_glyph_rect = 
+            get_res(
+                pos_in_start_line,
+                start_line
+            )?;
+
+        let start_line_last_glyph_rect = 
+            get_res(
+                start_line.len() - 1,
+                start_line
+            )?;
+
+        let top_left_coords =
+            start_glyph_rect.top_left_coords;
+
+        let height = start_glyph_rect.height;
+        let width = (start_line_last_glyph_rect.top_left_coords.x - start_glyph_rect.top_left_coords.x) + start_line_last_glyph_rect.width;
+
+        all_rects.push(
+            Rect {
+                top_left_coords,
+                width,
+                height,
+                color: colors::WHITE
+            }
+        );
+
+        //middle lines
+        let nr_mid_lines = (stop_line_indx - start_line_indx) - 1;
+        let first_mid_line = start_line_indx + 1;
+
+        for i in first_mid_line..(first_mid_line + nr_mid_lines)  {
+            let mid_line = get_res(i, glyph_bound_rects)?;
+
+            let mid_line_first_glyph_rect = 
+                get_res(
+                    0,
+                    mid_line
+                )?;
+
+            let mid_line_last_glyph_rect = 
+                get_res(
+                    mid_line.len() - 1,
+                    mid_line
+                )?;
+
+            let top_left_coords =
+                mid_line_first_glyph_rect.top_left_coords;
+
+            let height = mid_line_first_glyph_rect.height;
+            let width = (mid_line_last_glyph_rect.top_left_coords.x - mid_line_first_glyph_rect.top_left_coords.x) + mid_line_last_glyph_rect.width;
+
+            all_rects.push(
+                Rect {
+                    top_left_coords,
+                    width,
+                    height,
+                    color: colors::WHITE
+                }
+            );
+        }
+
+        //last line
+        let stop_line = get_res(stop_line_indx, glyph_bound_rects)?;
+
+        let stop_line_first_glyph_rect = 
+        get_res(
+            0,
+            stop_line
+        )?;
+
+        let stop_glyph_rect = 
+            get_res(
+                pos_in_stop_line,
+                stop_line
+            )?;
+
+        let top_left_coords =
+            stop_line_first_glyph_rect.top_left_coords;
+
+        let height = stop_glyph_rect.height;
+        let width = (stop_glyph_rect.top_left_coords.x - stop_line_first_glyph_rect.top_left_coords.x) + stop_glyph_rect.width;
+
+        all_rects.push(
+            Rect {
+                top_left_coords,
+                width,
+                height,
+                color: colors::WHITE
+            }
+        );
+        
+        Ok(all_rects)
+    }
+}

editor/src/vec_result.rs

@@ -6,7 +6,7 @@ use snafu::{OptionExt};
 
 // replace vec methods that return Option with ones that return Result and proper Error
 
-pub fn get_res<T>(index: usize, vec: &Vec<T>) -> EdResult<&<usize as SliceIndex<[T]>>::Output> {
+pub fn get_res<T>(index: usize, vec: &[T]) -> EdResult<&<usize as SliceIndex<[T]>>::Output> {
 
     let elt_ref = vec.get(index).context(OutOfBounds {
         index,