feat: Introduce a WordArea struct

Useful to highlight matching areas in the original text.

examples/query-database.rs

@@ -2,10 +2,12 @@ use std::io::{self, Write};
 use std::path::PathBuf;
 use std::error::Error;
 
+use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
 use serde_derive::{Serialize, Deserialize};
 use structopt::StructOpt;
 
 use meilidb::database::Database;
+use meilidb::Match;
 
 #[derive(Debug, StructOpt)]
 pub struct Opt {
@@ -26,6 +28,40 @@ struct Document {
     image: String,
 }
 
+fn display_highlights(text: &str, ranges: &[usize]) -> io::Result<()> {
+    let mut stdout = StandardStream::stdout(ColorChoice::Always);
+    let mut highlighted = false;
+
+    for range in ranges.windows(2) {
+        let [start, end] = match range { [start, end] => [*start, *end], _ => unreachable!() };
+        if highlighted {
+            stdout.set_color(ColorSpec::new().set_fg(Some(Color::Yellow)))?;
+        }
+        write!(&mut stdout, "{}", &text[start..end])?;
+        stdout.reset()?;
+        highlighted = !highlighted;
+    }
+
+    Ok(())
+}
+
+fn create_highlight_areas(text: &str, matches: &[Match], attribute: u16) -> Vec<usize> {
+    let mut title_areas = Vec::new();
+
+    title_areas.push(0);
+    for match_ in matches {
+        if match_.attribute.attribute() == attribute {
+            let word_area = match_.word_area;
+            let byte_index = word_area.byte_index() as usize;
+            let length = word_area.length() as usize;
+            title_areas.push(byte_index);
+            title_areas.push(byte_index + length);
+        }
+    }
+    title_areas.push(text.len());
+    title_areas
+}
+
 fn main() -> Result<(), Box<Error>> {
     let opt = Opt::from_args();
 
@@ -41,26 +77,35 @@ fn main() -> Result<(), Box<Error>> {
         io::stdout().flush()?;
 
         if input.read_line(&mut buffer)? == 0 { break }
+        let query = buffer.trim_end_matches('\n');
 
         let view = database.view();
 
         let (elapsed, documents) = elapsed::measure_time(|| {
             let builder = view.query_builder().unwrap();
-            builder.query(&buffer, 0..opt.number_results)
+            builder.query(query, 0..opt.number_results)
         });
 
-        let mut full_documents = Vec::with_capacity(documents.len());
+        let number_of_documents = documents.len();
+        for doc in documents {
+            match view.retrieve_document::<Document>(doc.id) {
+                Ok(document) => {
 
-        for document in documents {
-            match view.retrieve_document::<Document>(document.id) {
-                Ok(document) => full_documents.push(document),
+                    print!("title: ");
+                    let title_areas = create_highlight_areas(&document.title, &doc.matches, 1);
+                    display_highlights(&document.title, &title_areas)?;
+                    println!();
+
+                    print!("description: ");
+                    let description_areas = create_highlight_areas(&document.description, &doc.matches, 2);
+                    display_highlights(&document.description, &description_areas)?;
+                    println!();
+                },
                 Err(e) => eprintln!("{}", e),
             }
         }
 
-        println!("{:#?}", full_documents);
-        println!("Found {} results in {}", full_documents.len(), elapsed);
-
+        println!("Found {} results in {}", number_of_documents, elapsed);
         buffer.clear();
     }