Add `empty_result!` macro and `REPL` resource, improve examples

1 files changed, 142 insertions, 0 deletions

diff --git a/examples/example-repl/src/main.rs b/examples/example-repl/src/main.rs
new file mode 100644
index 0000000..2eb92e1
--- /dev/null
+++ b/examples/example-repl/src/main.rs
@@ -0,0 +1,142 @@
+use mingling::{REPL, hook::ProgramHook, prelude::*, this};
+use std::{env::current_dir, path::PathBuf};
+
+// Resource to store the current directory
+#[derive(Clone)]
+struct CurrentDir {
+    dir: PathBuf,
+}
+
+impl Default for CurrentDir {
+    fn default() -> Self {
+        Self {
+            dir: current_dir().unwrap(),
+        }
+    }
+}
+
+fn main() {
+    let mut program = ThisProgram::new();
+
+    // Add resource
+    program.with_resource(CurrentDir::default());
+
+    // Add dispatchers
+    program.with_dispatcher(ChangeDirectoryCommand);
+    program.with_dispatcher(ListCommand);
+    program.with_dispatcher(ExitCommand);
+
+    // Add hooks to handle REPL-related events
+    program.with_hook(
+        ProgramHook::empty()
+            .on_repl_begin(|| {
+                // Print welcome message
+                println!("Welcome!")
+            })
+            .on_repl_pre_readline(|| {
+                // Print prompt
+                let res = this::<ThisProgram>().res::<CurrentDir>().unwrap();
+                let dir_str: String = res.dir.to_string_lossy().into();
+                let prompt = format!(
+                    "{}> ",
+                    dir_str
+                        .replace(&['/', '\\'][..], ">")
+                        .trim_start_matches('>')
+                        .trim_end_matches('>')
+                );
+                print!("{}", prompt)
+            })
+            .on_repl_receive_result(|r| {
+                // Print output
+                if !r.is_empty() {
+                    println!("{}", r.trim())
+                }
+            }),
+    );
+
+    // Start the REPL loop
+    program.exec_repl();
+}
+
+// Create error route
+pack!(ErrorDirectoryNotExist = PathBuf);
+
+// Create commands: cd ls exit
+dispatcher!("cd", ChangeDirectoryCommand => ChangeDirectoryEntry);
+dispatcher!("ls", ListCommand => ListEntry);
+dispatcher!("exit", ExitCommand => ExitEntry);
+
+// Define data needed for the cd command's execution phase
+pack!(StateChangeDirectory = String);
+
+// Define data needed for the ls command's rendering phase
+pack!(ResultList = Vec<String>);
+
+// Parse cd command arguments
+#[chain]
+fn parse_cd_args(prev: ChangeDirectoryEntry) -> Next {
+    let join = prev.pick(()).unpack();
+    StateChangeDirectory::new(join)
+}
+
+// Execute directory change
+#[chain]
+fn handle_cd(prev: StateChangeDirectory, current_dir: &mut CurrentDir) -> Next {
+    let join = prev.inner;
+    let new_dir = just_fmt::fmt_path::fmt_path(current_dir.dir.join(join)).unwrap_or_default();
+
+    // If the path is not found, route to error handling
+    if !new_dir.exists() {
+        return ErrorDirectoryNotExist::new(new_dir).to_render();
+    }
+
+    current_dir.dir = new_dir;
+    empty_result!()
+}
+
+// Get directory contents via the CurrentDir resource
+#[chain]
+fn handle_ls(_prev: ListEntry, current_dir: &CurrentDir) -> Next {
+    let dir = &current_dir.dir;
+    let entries: Vec<String> = std::fs::read_dir(dir)
+        .into_iter()
+        .flat_map(|rd| rd.filter_map(|e| e.ok()))
+        .map(|e| {
+            let name = e.file_name().to_string_lossy().to_string();
+            if e.file_type().map(|t| t.is_dir()).unwrap_or(false) {
+                format!("{}/", name)
+            } else {
+                name
+            }
+        })
+        .collect();
+
+    // Render ResultList
+    ResultList::new(entries).to_render()
+}
+
+// Render ResultList data
+#[renderer]
+fn render_list(list: ResultList) {
+    for item in list.inner {
+        r_println!("{}", item)
+    }
+}
+
+// Handle exit command event
+#[chain]
+fn handle_exit(
+    _prev: ExitEntry,
+    repl: &mut REPL, // Import REPL resource, registered in `exec_repl`, usable directly
+) {
+    // Set the REPL exit flag; REPL will exit after this loop iteration
+    repl.exit = true;
+}
+
+// Handle path not found event
+#[renderer]
+fn render_error_directory_not_exist(err: ErrorDirectoryNotExist) {
+    r_println!("Directory not found: {}", err.inner.display())
+}
+
+gen_program!();