cargo fmt

demo/demo.rpy

@@ -1,9 +1,13 @@
 # Control testing
-$ x = "3"
-"Bob will be here in [x] seconds."
-$ x = "2"
-"Bob will be here in [x] seconds."
-$ x = "1"
+if True:
+    let x = "3"
+    "Bob will be here in [x] seconds."
+    let x = "2"
+    "Bob will be here in [x] seconds."
+    if True:
+        let x = "213"
+    let x = "1"
+    "Bob will be here in [x] seconds."
 "Bob will be here in [x] seconds."
 "Bob" "I will not say anything, [foo]"
 define foo = "bar"

renrs-gui/src/lib.rs

@@ -163,10 +163,10 @@ impl App {
             }
 
             let Vector2f { x, y } = shape.position();
-            if x >= WIDTH - SIZE || x < 0.0 {
+            if !(0.0..WIDTH - SIZE).contains(&x) {
                 velocity.x *= -1.0;
             }
-            if y >= HEIGHT - SIZE || y < 0.0 {
+            if !(0.0..HEIGHT - SIZE).contains(&y) {
                 velocity.y *= -1.0;
             }
             shape.set_position(Vector2f::new(x + velocity.x, y + velocity.y));

renrs/src/lib.rs

@@ -18,17 +18,19 @@ impl State {
         }
     }
 
-    pub fn next(&mut self) -> Option<Event> {
+    fn next_command(&mut self) -> Option<CommandContext> {
+        self.script.borrow_mut().next(&self.script)
+    }
+}
+impl Iterator for State {
+    type Item = Event;
+    fn next(&mut self) -> Option<Self::Item> {
         while let Some(command) = self.next_command() {
             let event = command.execute();
-            if let Some(_) = event {
+            if event.is_some() {
                 return event;
             }
         }
         None
     }
-
-    fn next_command(&mut self) -> Option<CommandContext> {
-        self.script.borrow_mut().next(&self.script)
-    }
 }

renrs/src/parser/block.rs

@@ -2,7 +2,7 @@ use debug_cell::RefCell;
 use std::{collections::HashMap, rc::Rc};
 
 use super::{
-    command::{parse_command, Command},
+    command::{parse_command, AssignType, Command},
     control::{parse_control, Control},
     event::Event,
     token::Token,
@@ -14,7 +14,7 @@ pub struct CommandBlock {
     control: Option<Control>,
     elements: Vec<BlockElement>,
     next: Option<usize>,
-    pub variables: Option<Rc<RefCell<HashMap<String, Token>>>>,
+    pub variables: Rc<RefCell<HashMap<String, Token>>>,
 }
 
 pub struct CommandContext {
@@ -24,6 +24,7 @@ pub struct CommandContext {
 
 impl CommandContext {
     pub fn execute(&self) -> Option<Event> {
+        use AssignType::*;
         use Command::*;
         Some(
             match &self.command {
@@ -31,8 +32,13 @@ impl CommandContext {
                     name: name.clone(),
                     text: text.clone(),
                 },
-                Define { .. } => panic!("define command should not be executed at runtime!"),
-                Assign { variable, value } => {
+                Command::Assign {
+                    assign_type,
+                    variable,
+                    value,
+                } => match assign_type {
+                    Define => panic!("define command should not be executed at runtime!"),
+                    GlobalAssign => {
                         if let Token::Keyword(_) = value {
                             todo!("assignment variable interpolation isn't implemented");
                         }
@@ -46,11 +52,28 @@ impl CommandContext {
                         root.borrow_mut()
                             .variables
                             .as_ref()
-                        .unwrap()
                             .borrow_mut()
                             .insert(variable.clone(), value.clone());
                         return None;
                     }
+                    Let => {
+                        if let Token::Keyword(_) = value {
+                            todo!("assignment variable interpolation isn't implemented");
+                        }
+                        self.context
+                            .borrow()
+                            .variables
+                            .borrow_mut()
+                            .insert(variable.clone(), value.clone());
+                        return None;
+                    }
+                    Assign => {
+                        if let Token::Keyword(_) = value {
+                            todo!("assignment variable interpolation isn't implemented");
+                        }
+                        todo!("local variable assignment isn't implemented")
+                    }
+                },
                 Eat { .. } => return None,
             }
             .process(&self.context),
@@ -59,7 +82,7 @@ impl CommandContext {
 }
 
 impl CommandBlock {
-    pub fn next<'a>(&mut self, self_rc: &Rc<RefCell<Self>>) -> Option<CommandContext> {
+    pub fn next(&mut self, self_rc: &Rc<RefCell<Self>>) -> Option<CommandContext> {
         let mut next = match self.next {
             Some(next) => next,
             None => return None,
@@ -79,7 +102,7 @@ impl CommandBlock {
                     next += 1;
                     break;
                 }
-                BlockElement::Block(block) => match block.borrow_mut().next(&block) {
+                BlockElement::Block(block) => match block.borrow_mut().next(block) {
                     Some(context_command) => {
                         result = Some(context_command);
                         break;
@@ -102,9 +125,7 @@ impl CommandBlock {
     }
 
     pub fn get_variables(&self) -> HashMap<String, Token> {
-        match &self.variables {
-            Some(variables) => {
-                let variables = variables.borrow().clone();
+        let variables = self.variables.borrow().clone();
         if let Some(parent) = &self.parent {
             let mut parent_variables = parent.borrow().get_variables();
             parent_variables.extend(variables.into_iter());
@@ -113,13 +134,10 @@ impl CommandBlock {
             variables
         }
     }
-            None => HashMap::new(),
-        }
-    }
 
     pub fn get_root(&self, self_rc: &Rc<RefCell<Self>>) -> Rc<RefCell<Self>> {
         if let Some(parent) = &self.parent {
-            parent.borrow().get_root(&parent)
+            parent.borrow().get_root(parent)
         } else {
             self_rc.clone()
         }
@@ -133,7 +151,7 @@ impl Default for CommandBlock {
             control: None,
             elements: Vec::new(),
             next: Some(0),
-            variables: None,
+            variables: Rc::new(RefCell::new(HashMap::new())),
         }
     }
 }
@@ -152,9 +170,9 @@ pub fn parse_block(
     let definitions = definitions.unwrap_or(Rc::new(RefCell::new(HashMap::new())));
     let block_rc = Rc::new(RefCell::new(CommandBlock {
         variables: if is_root {
-            Some(definitions.clone())
+            definitions.clone()
         } else {
-            None
+            Default::default()
         },
         ..Default::default()
     }));
@@ -173,7 +191,11 @@ pub fn parse_block(
                         continue;
                     }
                     Rule::Line => BlockElement::Command(match parse_command(pair) {
-                        Command::Define { variable, value } => {
+                        Command::Assign {
+                            variable,
+                            value,
+                            assign_type: AssignType::Define,
+                        } => {
                             let mut value = value;
                             if let Token::Keyword(keyword) = value {
                                 value = definitions
@@ -191,13 +213,7 @@ pub fn parse_block(
                         let subblock_rc = parse_block(pair, Some(definitions.clone()));
                         {
                             let mut subblock = subblock_rc.borrow_mut();
-                            if let Some(control) = control.as_ref() {
-                                if control.has_variable_scope() {
-                                    // TODO: Sublock-scoped variables
-                                    subblock.variables =
-                                        Some(Rc::new(RefCell::new(HashMap::new())));
-                                }
-                            } else {
+                            if control.is_none() {
                                 panic!("block should have control");
                             }
                             subblock.parent = Some(block_rc.clone());
@@ -213,7 +229,7 @@ pub fn parse_block(
             elements
         };
         if is_root {
-            block.variables = Some(definitions);
+            block.variables = definitions;
         }
     }
     block_rc

renrs/src/parser/command.rs

@@ -1,3 +1,5 @@
+use std::str::FromStr;
+
 use super::{
     token::Token,
     utils::{describe_line, parse_line},
@@ -7,10 +9,41 @@ use super::{
 #[derive(Debug, Clone)]
 #[allow(dead_code)]
 pub enum Command {
-    Say { name: Option<String>, text: String },
-    Eat { food: String, politely: bool },
-    Define { variable: String, value: Token },
-    Assign { variable: String, value: Token },
+    Say {
+        name: Option<String>,
+        text: String,
+    },
+    Eat {
+        food: String,
+        politely: bool,
+    },
+    Assign {
+        assign_type: AssignType,
+        variable: String,
+        value: Token,
+    },
+}
+
+#[derive(Debug, Clone)]
+pub enum AssignType {
+    Define,
+    GlobalAssign,
+    Let,
+    Assign,
+}
+
+impl FromStr for AssignType {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        use AssignType::*;
+        Ok(match s {
+            "define" => Define,
+            "$" => GlobalAssign,
+            "let" => Let,
+            _ => return Err(()),
+        })
+    }
 }
 
 pub fn parse_command(pair: Pair) -> Command {
@@ -31,22 +64,15 @@ pub fn parse_command(pair: Pair) -> Command {
             name: Some(name.clone()),
             text: text.clone(),
         },
-        [Keyword(keyword), Keyword(variable), Keyword(equals), value]
-            if keyword.eq("define") && equals.eq("=") =>
-        {
-            Define {
+        // https://github.com/rust-lang/rust/issues/51114
+        [Keyword(keyword), Keyword(variable), Keyword(equals), value] if equals.eq("=") => Assign {
+            assign_type: match keyword.parse() {
+                Ok(assign_type) => assign_type,
+                Err(_) => unknown!(),
+            },
             variable: variable.clone(),
             value: value.clone(),
-            }
-        }
-        [Keyword(keyword), Keyword(variable), Keyword(equals), value]
-            if keyword.eq("$") && equals.eq("=") =>
-        {
-            Assign {
-                variable: variable.clone(),
-                value: value.clone(),
-            }
-        }
+        },
         [Keyword(keyword), Str(food), tail @ ..] if keyword.eq("eat") => Eat {
             food: food.to_owned(),
             politely: match tail {

renrs/src/parser/control.rs

@@ -10,14 +10,6 @@ pub enum Control {
     If { condition: bool },
 }
 
-impl Control {
-    pub fn has_variable_scope(&self) -> bool {
-        match self {
-            _ => false,
-        }
-    }
-}
-
 pub fn parse_control(pair: Pair) -> Control {
     use Control::*;
     use Token::*;

renrs/src/parser/event.rs

@@ -19,8 +19,8 @@ impl Event {
                 let variables = context.get_variables();
                 *name = name
                     .as_deref()
-                    .map(|name| interpolate_string(&name, &variables));
-                *text = interpolate_string(&text, &variables);
+                    .map(|name| interpolate_string(name, &variables));
+                *text = interpolate_string(text, &variables);
             }
         }
         self
@@ -34,7 +34,7 @@ fn interpolate_string(input: &str, variables: &HashMap<String, Token>) -> String
         if let Some(value) = variables.get(var_name) {
             value.to_string()
         } else {
-            format!("[{}]", var_name)
+            panic!("undefined variable `{var_name}`");
         }
     });
 

renrs/src/parser/token.rs

@@ -78,6 +78,6 @@ pub fn parse_token(pair: Pair) -> Token {
         }),
         Rule::Number => Token::Number(pair.as_str().parse().unwrap()),
         Rule::Keyword => Token::Keyword(pair.as_str().to_owned()),
-        __ => unreachable!(),
+        _ => unreachable!(),
     }
 }

renrs/src/parser/utils.rs

@@ -4,7 +4,7 @@ use super::{
 };
 
 pub fn parse_line(pair: Pair) -> Vec<Token> {
-    pair.into_inner().map(|pair| parse_token(pair)).collect()
+    pair.into_inner().map(parse_token).collect()
 }
 
 // Line description e.g. [String, Keyword, Array]
@@ -12,10 +12,10 @@ pub fn parse_line(pair: Pair) -> Vec<Token> {
 pub fn describe_line(line: &[Token]) -> String {
     let mut description = "[".to_owned();
     let mut iter = line.iter();
-    description.push_str(&format!("{}", iter.next().unwrap().print()));
+    description.push_str(iter.next().unwrap().print());
     for token in iter {
         description.push_str(&format!(", {}", token.print()));
     }
-    description.push_str("]");
+    description.push(']');
     description
 }