Implement a basic TUI example for using yarnspinner standalone (fixes #123)

Cargo.toml

@@ -12,6 +12,7 @@ members = [
     "crates/codegen",
     "demo",
     "examples/bevy_yarnspinner",
+    "examples/yarnspinner_without_bevy",
 ]
 
 # Source: https://github.com/bevyengine/bevy/blob/main/examples/README.md#1-tweak-your-cargotoml

crates/core/src/lib.rs

@@ -19,8 +19,10 @@ mod yarn_value;
 
 pub mod prelude {
     //! Types and functions used all throughout the runtime and compiler.
+    #[cfg(any(feature = "bevy", feature = "serde"))]
+    pub use crate::feature_gates::*;
+
     pub use crate::{
-        feature_gates::*,
         generated::{
             instruction::OpCode, operand::Value as OperandValue, Header, Instruction,
             InvalidOpCodeError, Node, Operand, Program,

examples/bevy_yarnspinner/Cargo.toml

@@ -13,3 +13,19 @@ publish = false
 bevy = "0.13"
 bevy_yarnspinner = { path = "../../crates/bevy_plugin", version = "0.2" }
 bevy_yarnspinner_example_dialogue_view = { path = "../../crates/example_dialogue_view", version = "0.2" }
+
+[[bin]]
+name = "access_variables"
+doc = false
+
+[[bin]]
+name = "custom_command"
+doc = false
+
+[[bin]]
+name = "custom_function"
+doc = false
+
+[[bin]]
+name = "hello_world"
+doc = false

examples/yarnspinner_without_bevy/Cargo.toml

@@ -0,0 +1,32 @@
+[package]
+name = "yarnspinner_without_bevy_examples"
+version = "0.1.0"
+edition = "2021"
+repository = "https://github.com/YarnSpinnerTool/YarnSpinner-Rust"
+homepage = "https://docs.yarnspinner.dev/"
+keywords = ["gamedev", "dialog", "yarn", "bevy"]
+categories = ["game-development", "compilers"]
+authors = ["Joe Clay <[email protected]>"]
+publish = false
+
+[dependencies]
+crossterm = "0.27"
+ratatui = "0.26"
+anyhow = "1.0"
+yarnspinner = { path = "../../crates/yarnspinner", version = "0.2" }
+
+[[bin]]
+name = "access_variables"
+doc = false
+
+[[bin]]
+name = "custom_command"
+doc = false
+
+[[bin]]
+name = "custom_function"
+doc = false
+
+[[bin]]
+name = "hello_world"
+doc = false

examples/yarnspinner_without_bevy/assets/dialogue/access_variables.yarn

@@ -0,0 +1,6 @@
+title: AccessVariables
+---
+Setting $foo to 1 after you continue this line
+<<set $foo to 1>>
+$foo is now {$foo}. This information should also be printed in your console once the UI exits.
+===

examples/yarnspinner_without_bevy/assets/dialogue/custom_command.yarn

@@ -0,0 +1,8 @@
+title: CustomCommand
+---
+When a command is encountered, a 'Command' DialogueEvent will be triggered.
+You can handle this in your game code to do anything you'd like.
+For example, here's a command that changes the background of the terminal!
+<<set_background "cyan">>
+Ooh, pretty.
+===

examples/yarnspinner_without_bevy/assets/dialogue/custom_function.yarn

@@ -0,0 +1,6 @@
+title: CustomFunction
+---
+Rust functions can be registered into your dialogue's library to make them runnable via Yarn.
+Let's take a look at a custom function now!
+pow(2,3) = {pow(2,3)}
+===

examples/yarnspinner_without_bevy/assets/dialogue/hello_world.yarn

@@ -0,0 +1,34 @@
+title: HelloWorld
+---
+Hello World! To continue the dialogue, press the enter key. You can also press Q to quit.
+These are options. You can select one by clicking on it or pressing the corresponding number on your keyboard.
+-> Some cool option
+-> Some other cool option
+Now we'll jump to another node!
+<<jump AnotherNode>>
+
+===
+
+title: AnotherNode
+---
+Now, a character will talk. Notice how the upper left corner of the dialogue will show their name.
+Hohenheim: Hi, I'm Jan Hohenheim, creator of Yarn Spinner for Rust. I hope you enjoy using it!
+Let's set a condition. Do you prefer dogs or cats?
+-> Dogs
+    <<set $animal = "dog">>
+-> Cats
+    <<set $animal = "cats">>
+-> Turtles
+    I, uuuh... okay, why not.
+    <<set $animal = "turtles">>
+Now let's print the result of the condition. Your preference is...
+(Drum roll)
+<<if $animal == "dog">>
+Dogs! Arf Arf!
+<<elseif $animal == "cats">>
+Cats! (Can't say I agree, but you do you)
+<<else>>
+Turtles! Solid choice.
+<<endif>>
+Et voilà! That was all. Thanks for checking out Yarn Spinner for Rust! Continuing from the last node will exit the dialogue.
+===

examples/yarnspinner_without_bevy/src/bin/access_variables.rs

@@ -0,0 +1,24 @@
+use yarnspinner::core::YarnValue;
+use yarnspinner_without_bevy_examples::TuiDialogueRunner;
+
+fn main() -> anyhow::Result<()> {
+    // See lib.rs for more details on how this works!
+    let mut runner =
+        TuiDialogueRunner::new("./assets/dialogue/access_variables.yarn", "AccessVariables")?;
+
+    runner.set_variable("$foo", YarnValue::Number(0.0))?;
+
+    println!(
+        "Value of $foo before dialogue: {:?}",
+        runner.get_variable("$foo")?
+    );
+
+    runner.run()?;
+
+    println!(
+        "Value of $foo after dialogue: {:?}",
+        runner.get_variable("$foo")?
+    );
+
+    Ok(())
+}

examples/yarnspinner_without_bevy/src/bin/custom_command.rs

@@ -0,0 +1,6 @@
+use yarnspinner_without_bevy_examples::TuiDialogueRunner;
+
+fn main() -> anyhow::Result<()> {
+    // See lib.rs for more details on how this works!
+    TuiDialogueRunner::new("./assets/dialogue/custom_command.yarn", "CustomCommand")?.run()
+}