feat(semantics): add boolean semantics

TODO: Testing this

argus-semantics/src/eval.rs

@@ -0,0 +1,40 @@
+use argus_core::{
+    expr::NumExpr,
+    signals::{AnySignal, ConstantSignal},
+};
+
+use crate::{utils::signal_num_op_impl, Trace};
+
+/// Helper struct to evaluate a [`NumExpr`] given a trace.
+pub struct NumExprEval;
+
+impl NumExprEval {
+    pub fn eval(root: &NumExpr, trace: &impl Trace) -> AnySignal {
+        match root {
+            NumExpr::IntLit(val) => ConstantSignal::new(*val).into(),
+            NumExpr::UIntLit(val) => ConstantSignal::new(*val).into(),
+            NumExpr::FloatLit(val) => ConstantSignal::new(*val).into(),
+            NumExpr::IntVar { name } | NumExpr::UIntVar { name } | NumExpr::FloatVar { name } => {
+                // TODO(anand): Type check!
+                trace.get(name.as_str()).cloned().unwrap()
+            }
+            NumExpr::Neg { arg } => {
+                let arg_sig = Self::eval(arg, trace);
+                signal_num_op_impl!(-arg_sig)
+            }
+            NumExpr::Add { args } => {
+                let args_signals = args.iter().map(|arg| Self::eval(arg, trace));
+                args_signals.reduce(|acc, arg| signal_num_op_impl!(acc + arg)).unwrap()
+            }
+            NumExpr::Mul { args } => {
+                let args_signals = args.iter().map(|arg| Self::eval(arg, trace));
+                args_signals.reduce(|acc, arg| signal_num_op_impl!(acc * arg)).unwrap()
+            }
+            NumExpr::Div { dividend, divisor } => {
+                let dividend = Self::eval(dividend, trace);
+                let divisor = Self::eval(divisor, trace);
+                signal_num_op_impl!(dividend / divisor)
+            }
+        }
+    }
+}