implement leo example command for lottery, tictactoe, token

errors/src/errors/cli/cli_errors.rs

@@ -164,4 +164,11 @@ create_messages!(
         msg: format!("Failed to execute the `execute` command.\nSnarkVM Error: {error}"),
         help: None,
     }
+
+    @backtraced
+    failed_to_write_file {
+        args: (error: impl Display),
+        msg: format!("Failed to write file.\nIO Error: {error}"),
+        help: None,
+    }
 );

leo/cli/cli.rs

@@ -34,9 +34,6 @@ pub struct CLI {
     #[clap(subcommand)]
     command: Commands,
 
-    #[clap(help = "Custom Aleo PM backend URL", env = "APM_URL")]
-    api: Option<String>,
-
     #[clap(long, global = true, help = "Optional path to Leo program root folder")]
     path: Option<PathBuf>,
 }
@@ -50,6 +47,11 @@ enum Commands {
     //     command: Init,
     // },
     //
+    #[clap(about = "Create a new Leo example package in a new directory")]
+    Example {
+        #[clap(subcommand)]
+        command: Example,
+    },
     #[clap(about = "Create a new Leo package in a new directory")]
     New {
         #[clap(flatten)]
@@ -132,6 +134,7 @@ pub fn run_with_args(cli: CLI) -> Result<()> {
             command.try_execute(context)
         }
         Commands::Clean { command } => command.try_execute(context),
+        Commands::Example { command } => command.try_execute(context),
         Commands::Run { command } => command.try_execute(context),
         Commands::Execute { command } => command.try_execute(context),
         Commands::Update { command } => command.try_execute(context),

leo/cli/commands/example.rs

@@ -0,0 +1,102 @@
+// Copyright (C) 2019-2023 Aleo Systems Inc.
+// This file is part of the Leo library.
+
+// The Leo library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// The Leo library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
+
+use super::*;
+
+use std::fs;
+
+/// The example programs that can be generated.
+#[derive(Parser, Debug)]
+pub enum Example {
+    #[clap(name = "lottery", about = "A public lottery program")]
+    Lottery,
+    #[clap(name = "tictactoe", about = "A standard tic-tac-toe game program")]
+    TicTacToe,
+    #[clap(name = "token", about = "A transparent & shielded custom token program")]
+    Token,
+}
+
+impl Command for Example {
+    type Input = <New as Command>::Output;
+    type Output = ();
+
+    fn prelude(&self, context: Context) -> Result<Self::Input> {
+        // Run leo new EXAMPLE_NAME
+        (New { name: self.name() }).execute(context)
+    }
+
+    fn apply(self, context: Context, _: Self::Input) -> Result<Self::Output>
+    where
+        Self: Sized,
+    {
+        let package_dir = context.dir()?;
+
+        // Write the main file.
+        let main_file_path = package_dir.join("src").join("main.leo");
+        fs::write(main_file_path, self.main_file_string()).map_err(CliError::failed_to_write_file)?;
+
+        // Write the input file.
+        let input_file_path = package_dir.join("inputs").join("input.in");
+        fs::write(input_file_path, self.input_file_string()).map_err(CliError::failed_to_write_file)?;
+
+        // Write the README file.
+        let readme_file_path = package_dir.join("README.md");
+        let readme_file_path_string = readme_file_path.display().to_string();
+        fs::write(readme_file_path, self.readme_file_string()).map_err(CliError::failed_to_write_file)?;
+
+        tracing::info!(
+            "🚀 To run the '{}' program follow the instructions at {}",
+            self.name().bold(),
+            readme_file_path_string
+        );
+
+        Ok(())
+    }
+}
+
+impl Example {
+    fn name(&self) -> String {
+        match self {
+            Example::Lottery => "lottery".to_string(),
+            Example::TicTacToe => "tictactoe".to_string(),
+            Example::Token => "token".to_string(),
+        }
+    }
+
+    fn main_file_string(&self) -> String {
+        match self {
+            Self::Lottery => include_str!("../../../examples/lottery/src/main.leo").to_string(),
+            Self::TicTacToe => include_str!("../../../examples/tictactoe/src/main.leo").to_string(),
+            Self::Token => include_str!("../../../examples/token/src/main.leo").to_string(),
+        }
+    }
+
+    fn input_file_string(&self) -> String {
+        match self {
+            Self::Lottery => include_str!("../../../examples/lottery/inputs/lottery.in").to_string(),
+            Self::TicTacToe => include_str!("../../../examples/tictactoe/inputs/tictactoe.in").to_string(),
+            Self::Token => include_str!("../../../examples/token/inputs/token.in").to_string(),
+        }
+    }
+
+    fn readme_file_string(&self) -> String {
+        match self {
+            Self::Lottery => include_str!("../../../examples/lottery/README.md").to_string(),
+            Self::TicTacToe => include_str!("../../../examples/tictactoe/README.md").to_string(),
+            Self::Token => include_str!("../../../examples/token/README.md").to_string(),
+        }
+    }
+}

leo/cli/commands/mod.rs

@@ -20,6 +20,9 @@ pub use build::Build;
 pub mod clean;
 pub use clean::Clean;
 
+pub mod example;
+pub use example::Example;
+
 pub mod execute;
 pub use execute::Execute;
 

leo/cli/commands/new.rs

@@ -22,7 +22,7 @@ use snarkvm::{cli::New as SnarkVMNew, file::AleoFile};
 #[derive(Parser, Debug)]
 pub struct New {
     #[clap(name = "NAME", help = "Set package name")]
-    name: String,
+    pub(crate) name: String,
 }
 
 impl Command for New {
@@ -43,8 +43,6 @@ impl Command for New {
             SnarkVMNew::try_parse_from([SNARKVM_COMMAND, &self.name]).map_err(CliError::failed_to_parse_new)?;
         let result = command.parse().map_err(CliError::failed_to_execute_new)?;
 
-        // todo: modify the readme file to recommend building with `leo build`.
-
         // Log the output of the `aleo new` command.
         tracing::info!("{}", result);
 

leo/package/src/example.rs

@@ -0,0 +1,42 @@
+// Copyright (C) 2019-2023 Aleo Systems Inc.
+// This file is part of the Leo library.
+
+// The Leo library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// The Leo library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
+
+use super::*;
+
+/// The example programs that can be generated.
+pub enum Example {
+    Lottery,
+    TicTacToe,
+    Token,
+}
+
+impl Example {
+    pub fn main_file_string(&self, package_name: &str) -> String {
+        match self {
+            Self::Lottery => include_str!("../../examples/lottery/src/main.leo").to_string(),
+            Self::TicTacToe => include_str!("../../examples/tic_tac_toe/src/main.leo").to_string(),
+            Self::Token => include_str!("../../examples/token/src/main.leo").to_string(),
+        }
+    }
+
+    pub fn input_file_string(&self, package_name: &str) -> String {
+        match self {
+            Self::Lottery => include_str!("../../examples/lottery/inputs/input.in").to_string(),
+            Self::TicTacToe => include_str!("../../examples/tic_tac_toe/inputs/input.in").to_string(),
+            Self::Token => include_str!("../../examples/token/inputs/input.in").to_string(),
+        }
+    }
+}