Working let statements

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/src/parser/block.rs

@@ -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 {
@@ -46,7 +46,17 @@ impl CommandContext {
                     root.borrow_mut()
                         .variables
                         .as_ref()
-                        .unwrap()
+                        .borrow_mut()
+                        .insert(variable.clone(), value.clone());
+                    return None;
+                },
+                Let { variable, value } => {
+                    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;
@@ -102,18 +112,13 @@ impl CommandBlock {
     }
 
     pub fn get_variables(&self) -> HashMap<String, Token> {
-        match &self.variables {
-            Some(variables) => {
-                let variables = variables.borrow().clone();
-                if let Some(parent) = &self.parent {
-                    let mut parent_variables = parent.borrow().get_variables();
-                    parent_variables.extend(variables.into_iter());
-                    parent_variables
-                } else {
-                    variables
-                }
-            }
-            None => HashMap::new(),
+        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());
+            parent_variables
+        } else {
+            variables
         }
     }
 
@@ -133,7 +138,7 @@ impl Default for CommandBlock {
             control: None,
             elements: Vec::new(),
             next: Some(0),
-            variables: None,
+            variables: Rc::new(RefCell::new(HashMap::new())),
         }
     }
 }
@@ -152,9 +157,9 @@ 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()
     }));
@@ -191,13 +196,7 @@ 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 +212,7 @@ pub fn parse_block(
             elements
         };
         if is_root {
-            block.variables = Some(definitions);
+            block.variables = definitions;
         }
     }
     block_rc

renrs/src/parser/command.rs

@@ -11,6 +11,7 @@ pub enum Command {
     Eat { food: String, politely: bool },
     Define { variable: String, value: Token },
     Assign { variable: String, value: Token },
+    Let { variable: String, value: Token },
 }
 
 pub fn parse_command(pair: Pair) -> Command {
@@ -47,6 +48,14 @@ pub fn parse_command(pair: Pair) -> Command {
                 value: value.clone(),
             }
         }
+        [Keyword(keyword), Keyword(variable), Keyword(equals), value]
+            if keyword.eq("let") && equals.eq("=") =>
+        {
+            Let {
+                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::*;