Add syntaxes and themes method

examples/advanced.rs

@@ -1,5 +1,5 @@
 /// A program that prints its own source code using the bat library
-use bat::{LineRange, PrettyPrinter, WrappingMode, PagingMode};
+use bat::{LineRange, PagingMode, PrettyPrinter, WrappingMode};
 
 fn main() {
     PrettyPrinter::new()

examples/list_syntaxes_and_themes.rs

@@ -0,0 +1,18 @@
+/// A simple program that prints its own source code using the bat library
+use bat::PrettyPrinter;
+
+fn main() {
+    let printer = PrettyPrinter::new();
+
+    println!("Syntaxes:");
+    for syntax in printer.syntaxes() {
+        println!("- {} ({})", syntax.name, syntax.file_extensions.join(", "));
+    }
+
+    println!();
+
+    println!("Themes:");
+    for theme in printer.themes() {
+        println!("- {}", theme);
+    }
+}

src/assets.rs

@@ -164,8 +164,8 @@ impl HighlightingAssets {
         self.syntax_set.syntaxes()
     }
 
-    pub fn themes(&self) -> impl Iterator<Item = &String> {
-        self.theme_set.themes.keys()
+    pub fn themes(&self) -> impl Iterator<Item = &str> {
+        self.theme_set.themes.keys().map(|s| s.as_ref())
     }
 
     pub(crate) fn get_theme(&self, theme: &str) -> &Theme {

src/pretty_printer.rs

@@ -2,6 +2,7 @@ use std::ffi::OsStr;
 use std::io::Read;
 
 use console::Term;
+use syntect::parsing::SyntaxReference;
 
 use crate::{
     assets::HighlightingAssets,
@@ -201,6 +202,14 @@ impl<'a> PrettyPrinter<'a> {
         self
     }
 
+    pub fn themes(&self) -> impl Iterator<Item = &str> {
+        self.assets.themes()
+    }
+
+    pub fn syntaxes(&self) -> impl Iterator<Item = &SyntaxReference> {
+        self.assets.syntaxes().iter()
+    }
+
     /// Pretty-print all specified inputs. This method will "use" all stored inputs.
     /// If you want to call 'print' multiple times, you have to call the appropriate
     /// input_* methods again.