From 395d086f0dce355ccdcf3da149c309826c539b48 Mon Sep 17 00:00:00 2001
From: Mel <einebeere@gmail.com>
Date: Sat, 20 Nov 2021 00:31:28 +0100
Subject: Runtime types

---
 src/interpret/value.rs | 341 ++++++++-----------------------------------------
 1 file changed, 54 insertions(+), 287 deletions(-)

(limited to 'src/interpret/value.rs')

diff --git a/src/interpret/value.rs b/src/interpret/value.rs
index d108c68..45c177d 100644
--- a/src/interpret/value.rs
+++ b/src/interpret/value.rs
@@ -1,298 +1,90 @@
-use crate::parse::ast::{expression::Expression, nodes::FnNode};
-use std::{cell::RefCell, fmt::Display, rc::Rc};
-use thiserror::Error;
-
-use super::{
-    scope::ScopeChain,
-    walker::{Walker, WalkerError},
+use crate::{
+    parse::ast::nodes::{FnNode, Identifier},
+    types::{bag::TypeBag, Type},
 };
+use std::{cell::RefCell, collections::HashMap, fmt::Display, rc::Rc};
+
+use super::scope::ScopeChain;
 
 type ReferenceOnCopy<T> = Rc<RefCell<T>>;
 
 #[derive(Clone, Debug)]
-pub enum Value {
+pub struct Value {
+    pub variant: ValueVariant,
+    pub typ: Type,
+}
+
+#[derive(Clone, Debug)]
+pub enum ValueVariant {
     Str(String),
     Float(f64),
     Int(i64),
     Bool(bool),
     Array(ReferenceOnCopy<Vec<Value>>),
     Fn(ReferenceOnCopy<FnValue>),
+    Data(HashMap<Identifier, Value>),
     Void,
 }
 
 impl Value {
-    pub fn add(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Str(ref l) => match rhs {
-                Value::Str(r) => Ok(Value::Str(format!("{}{}", l, r))),
-                Value::Float(r) => Ok(Value::Str(format!("{}{}", l, r))),
-                Value::Int(r) => Ok(Value::Str(format!("{}{}", l, r))),
-                r => Err(OperationError::AddTypes(self, r)),
-            },
-            Value::Float(l) => match rhs {
-                Value::Str(r) => Ok(Value::Str(l.to_string() + &r)),
-                Value::Float(r) => Ok(Value::Float(l + r)),
-                Value::Int(r) => Ok(Value::Float(l + r as f64)),
-                r => Err(OperationError::AddTypes(self, r)),
-            },
-            Value::Int(l) => match rhs {
-                Value::Str(r) => Ok(Value::Str(l.to_string() + &r)),
-                Value::Float(r) => Ok(Value::Float(l as f64 + r)),
-                Value::Int(r) => Ok(Value::Int(l + r)),
-                r => Err(OperationError::AddTypes(self, r)),
-            },
-            _ => Err(OperationError::AddTypes(self, rhs)),
-        }
-    }
-
-    pub fn sub(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l - r)),
-                Value::Int(r) => Ok(Value::Float(l - r as f64)),
-                r => Err(OperationError::SubTypes(self, r)),
-            },
-            Value::Int(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l as f64 - r)),
-                Value::Int(r) => Ok(Value::Int(l - r)),
-                r => Err(OperationError::SubTypes(self, r)),
-            },
-            _ => Err(OperationError::SubTypes(self, rhs)),
-        }
-    }
-
-    pub fn mul(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l * r)),
-                Value::Int(r) => Ok(Value::Float(l * r as f64)),
-                r => Err(OperationError::MulTypes(self, r)),
-            },
-            Value::Int(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l as f64 * r)),
-                Value::Int(r) => Ok(Value::Int(l * r)),
-                r => Err(OperationError::MulTypes(self, r)),
-            },
-            _ => Err(OperationError::MulTypes(self, rhs)),
-        }
-    }
-
-    pub fn div(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l / r)),
-                Value::Int(r) => Ok(Value::Float(l / r as f64)),
-                r => Err(OperationError::DivTypes(self, r)),
-            },
-            Value::Int(l) => match rhs {
-                Value::Float(r) => Ok(Value::Float(l as f64 / r)),
-                Value::Int(r) => Ok(Value::Float(l as f64 / r as f64)),
-                r => Err(OperationError::DivTypes(self, r)),
-            },
-            _ => Err(OperationError::DivTypes(self, rhs)),
-        }
-    }
-
-    pub fn eq(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Str(l) => match rhs {
-                Value::Str(r) => Ok(Value::Bool(l == r)),
-                _ => Ok(Value::Bool(false)),
-            },
-            Value::Float(l) => match rhs {
-                Value::Float(r) => Ok(Value::Bool(l == r)),
-                _ => Ok(Value::Bool(false)),
-            },
-            Value::Int(l) => match rhs {
-                Value::Int(r) => Ok(Value::Bool(l == r)),
-                _ => Ok(Value::Bool(false)),
-            },
-            Value::Bool(l) => match rhs {
-                Value::Bool(r) => Ok(Value::Bool(l == r)),
-                _ => Ok(Value::Bool(false)),
-            },
-            _ => Ok(Value::Bool(false)),
-        }
-    }
-
-    pub fn neq(self, rhs: Value) -> Result<Value, OperationError> {
-        if let Ok(Value::Bool(value)) = self.eq(rhs) {
-            Ok(Value::Bool(!value))
-        } else {
-            unreachable!()
-        }
-    }
-
-    pub fn gt(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(r) => match rhs {
-                Value::Float(l) => Ok(Value::Bool(r > l)),
-                Value::Int(l) => Ok(Value::Bool(r > l as f64)),
-                r => Err(OperationError::CompareTypes(self, r)),
-            },
-            Value::Int(r) => match rhs {
-                Value::Float(l) => Ok(Value::Bool(r as f64 > l)),
-                Value::Int(l) => Ok(Value::Bool(r > l)),
-                r => Err(OperationError::CompareTypes(self, r)),
-            },
-            _ => Err(OperationError::CompareTypes(self, rhs)),
+    pub fn str(val: String, types: &TypeBag) -> Self {
+        Self {
+            variant: ValueVariant::Str(val),
+            typ: types.str(),
         }
     }
 
-    pub fn gte(self, rhs: Value) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(r) => match rhs {
-                Value::Float(l) => Ok(Value::Bool(r >= l)),
-                Value::Int(l) => Ok(Value::Bool(r >= l as f64)),
-                r => Err(OperationError::CompareTypes(self, r)),
-            },
-            Value::Int(r) => match rhs {
-                Value::Float(l) => Ok(Value::Bool(r as f64 >= l)),
-                Value::Int(l) => Ok(Value::Bool(r >= l)),
-                r => Err(OperationError::CompareTypes(self, r)),
-            },
-            _ => Err(OperationError::CompareTypes(self, rhs)),
+    pub fn int(val: i64, types: &TypeBag) -> Self {
+        Self {
+            variant: ValueVariant::Int(val),
+            typ: types.int(),
         }
     }
 
-    pub fn neg(self) -> Result<Value, OperationError> {
-        match self {
-            Value::Float(float) => Ok(Value::Float(-float)),
-            Value::Int(int) => Ok(Value::Int(-int)),
-            _ => Err(OperationError::NegType(self)),
+    pub fn float(val: f64, types: &TypeBag) -> Self {
+        Self {
+            variant: ValueVariant::Float(val),
+            typ: types.float(),
         }
     }
 
-    pub fn not(self) -> Result<Value, OperationError> {
-        match self {
-            Value::Bool(bool) => Ok(Value::Bool(bool)),
-            _ => Err(OperationError::NotType(self)),
+    pub fn bool(val: bool, types: &TypeBag) -> Self {
+        Self {
+            variant: ValueVariant::Bool(val),
+            typ: types.bool(),
         }
     }
 
-    pub fn subscript(self, index: Value) -> Result<Value, OperationError> {
-        let index = match index {
-            Value::Int(i) => i,
-            i => return Err(OperationError::ArrayIndexType(i)),
-        };
-
-        match self {
-            Value::Array(a) => {
-                let array = a.borrow();
-                if index < 0 || index as usize >= array.len() {
-                    Err(OperationError::ArrayIndexOutOfRange {
-                        index,
-                        length: array.len(),
-                    })
-                } else {
-                    Ok(array[index as usize].clone())
-                }
-            }
-            // Maybe allow string subscripts?
-            x => Err(OperationError::ArrayType(x.clone())),
-        }
-    }
-
-    pub fn subscript_assign(
-        &mut self,
-        index: Value,
-        value: Value,
-    ) -> Result<Value, OperationError> {
-        let index = match index {
-            Value::Int(i) => i,
-            i => return Err(OperationError::ArrayIndexType(i)),
-        };
-
-        match self {
-            Value::Array(a) => {
-                let mut array = a.borrow_mut();
-                if index < 0 || index as usize >= array.len() {
-                    Err(OperationError::ArrayIndexOutOfRange {
-                        index,
-                        length: array.len(),
-                    })
-                } else {
-                    array[index as usize] = value;
-                    Ok(array[index as usize].clone())
-                }
-            }
-            x => Err(OperationError::ArrayType(x.clone())),
+    pub fn void(types: &TypeBag) -> Self {
+        Self {
+            variant: ValueVariant::Void,
+            typ: types.void(),
         }
     }
 
-    pub fn call(&self, arguments: Vec<Value>) -> Result<Value, WalkerError> {
-        let called = match self {
-            Value::Fn(i) => i,
-            i => {
-                return Err(WalkerError::OperationError(OperationError::CallableType(
-                    i.clone(),
-                )))
-            }
-        }
-        .borrow();
-
-        // FIXME: Currently closures are able to re-assign values from the upper scopes.
-        // This is good behaviour, until a closure re-assigns a value that was declared after
-        // the closure even existed.
-        // Minimal reproducible example:
-        // ```rh
-        // closure = fn { y = 10; };
-        // y = 1;
-        // closure();
-        // print y;
-        // ```
-        // Expected: 1
-        // Actual: 10
-        let mut scope = called.scope.clone();
-        scope.nest();
-
-        let parameters = &called.node.header.parameters;
-
-        if parameters.len() != arguments.len() {
-            return Err(WalkerError::OperationError(
-                OperationError::WrongArgumentCount(parameters.len(), arguments.len()),
-            ));
-        }
-
-        for (argument, parameter) in arguments.into_iter().zip(parameters.iter()) {
-            scope.set_var_shadowed(&parameter.identifier, argument);
-        }
-
-        // Yes, we create a new walker for every function call,
-        // it's *way* easier that way.
-        let mut walker = Walker::new_with_scope(scope);
-        let result = walker.walk_expression(&Expression::Block(Box::new(called.node.body.clone())));
-
-        if let Err(WalkerError::Return(returned)) = result {
-            Ok(returned)
-        } else {
-            result
-        }
-    }
-}
-
-impl Value {
     pub fn type_name(&self) -> &'static str {
-        match self {
-            Value::Str(_) => "Str",
-            Value::Float(_) => "Float",
-            Value::Int(_) => "Int",
-            Value::Bool(_) => "Bool",
-            Value::Array(_) => "Array",
-            Value::Fn(_) => "Fn",
-            Value::Void => "Void",
+        // TODO: Base this off of the type.
+        match self.variant {
+            ValueVariant::Str(_) => "Str",
+            ValueVariant::Float(_) => "Float",
+            ValueVariant::Int(_) => "Int",
+            ValueVariant::Bool(_) => "Bool",
+            ValueVariant::Array(_) => "Array",
+            ValueVariant::Fn(_) => "Fn",
+            ValueVariant::Void => "Void",
+            _ => todo!(),
         }
     }
 }
 
 impl Display for Value {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            Value::Str(v) => write!(f, "{}", v),
-            Value::Float(v) => write!(f, "{}", v),
-            Value::Int(v) => write!(f, "{}", v),
-            Value::Bool(v) => write!(f, "{}", v),
-            Value::Array(a) => {
+        match &self.variant {
+            ValueVariant::Str(v) => write!(f, "{}", v),
+            ValueVariant::Float(v) => write!(f, "{}", v),
+            ValueVariant::Int(v) => write!(f, "{}", v),
+            ValueVariant::Bool(v) => write!(f, "{}", v),
+            ValueVariant::Array(a) => {
                 write!(
                     f,
                     "[{}]",
@@ -303,8 +95,9 @@ impl Display for Value {
                         .join(", ")
                 )
             }
-            Value::Fn(v) => write!(f, "<fn {:?}>", v.as_ptr()),
-            Value::Void => write!(f, "<void>"),
+            ValueVariant::Fn(v) => write!(f, "<fn {:?}>", v.as_ptr()),
+            ValueVariant::Void => write!(f, "<void>"),
+            _ => todo!(),
         }
     }
 }
@@ -315,30 +108,4 @@ pub struct FnValue {
     pub scope: ScopeChain,
 }
 
-#[derive(Error, Debug)]
-pub enum OperationError {
-    #[error("Can't add value '{0}' of type '{}' to value '{1}' of type '{}'.", .0.type_name(), .1.type_name())]
-    AddTypes(Value, Value),
-    #[error("Can't subtract value '{1}' of type '{}' from value '{0}' of type '{}'.", .1.type_name(), .0.type_name())]
-    SubTypes(Value, Value),
-    #[error("Can't multiply value '{0}' of type '{}' with value '{1}' of type '{}'.", .0.type_name(), .1.type_name())]
-    MulTypes(Value, Value),
-    #[error("Can't divide value '{0}' of type '{}' by value '{1}' of type '{}'.", .0.type_name(), .1.type_name())]
-    DivTypes(Value, Value),
-    #[error("Can't compare value '{0}' of type '{}' with value '{1}' of type '{}'.", .0.type_name(), .1.type_name())]
-    CompareTypes(Value, Value),
-    #[error("Can't negate value '{0}' of type '{}'.", .0.type_name())]
-    NegType(Value),
-    #[error("Can't flip value '{0}' of type '{}'.", .0.type_name())]
-    NotType(Value),
-    #[error("Can't use value '{0}' of type '{}' as a subsript index.", .0.type_name())]
-    ArrayIndexType(Value),
-    #[error("Can't subscript value '{0}' of type '{}'.", .0.type_name())]
-    ArrayType(Value),
-    #[error("Array index '{index}' out of range for array of length '{length}'.")]
-    ArrayIndexOutOfRange { index: i64, length: usize },
-    #[error("Can't call value '{0}' of type '{}'.", .0.type_name())]
-    CallableType(Value),
-    #[error("Function expects {0} arguments, but {1} were given.")]
-    WrongArgumentCount(usize, usize),
-}
+pub type ValueMap = HashMap<Identifier, Value>;
-- 
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