Add a 'course-content' binary (#1757)

This allows dumping the course content in order, which I've needed
several times to verify whether a concept is used before it is covered
-- for example in #1516 I want to make sure we don't use trait objects
before the Smart Pointers section.

mdbook-course/README.md

@@ -3,6 +3,12 @@
 This is an mdBook preprocessor to handle some specific details of Comprehensive
 Rust.
 
+It provides three binaries:
+
+- `mdbook-course` -- the actual preprocessor
+- `course-schedule` -- prints the course schedule with timings
+- `course-content` -- dumps all course content to stdout, in order
+
 ## Frontmatter
 
 The preprocessor parses "frontmatter" -- YAML between `---` at the beginning of

mdbook-course/src/bin/course-content.rs

@@ -0,0 +1,45 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use mdbook::MDBook;
+use mdbook_course::course::Courses;
+use std::fs;
+use std::path::Path;
+
+fn main() {
+    pretty_env_logger::init();
+    let root_dir = ".";
+    let mdbook = MDBook::load(root_dir).expect("Unable to load the book");
+    let (courses, _) = Courses::extract_structure(mdbook.book)
+        .expect("Unable to extract course structure");
+
+    let src_dir = Path::new("src");
+    for course in &courses {
+        println!("# COURSE: {}", course.name);
+        for session in course {
+            println!("# SESSION: {}", session.name);
+            for segment in session {
+                println!("# SEGMENT: {}", segment.name);
+                for slide in segment {
+                    println!("# SLIDE: {}", slide.name);
+                    for path in &slide.source_paths {
+                        let content =
+                            fs::read_to_string(src_dir.join(path)).unwrap();
+                        println!("{}", content);
+                    }
+                }
+            }
+        }
+    }
+}