Add ext system

1 files changed, 39 insertions, 0 deletions

diff --git a/src/assembler_eval.py b/src/assembler_eval.py
new file mode 100644
index 0000000..3473ab8
--- /dev/null
+++ b/src/assembler_eval.py
@@ -0,0 +1,39 @@
+constants: dict[str, str] = {
+  # Registers
+  "rz": "0",
+  "ra": "1",
+  "rb": "2",
+  "rc": "3",
+  "rd": "4",
+  "rf": "5",
+  "rg": "6",
+  # ALU instructions
+  "al_plus": "0",
+  "al_minus": "1",
+  "al_and": "2",
+  "al_or": "3",
+  "al_xor": "4",
+  "al_shift_lr": "5",
+  "al_shift_ar": "6",
+  "al_shift_ll": "7",
+  # ALU flags
+  "f_carry": "0",
+  "f_overflow": "1",
+  "f_zero": "2",
+  "f_sign": "3",
+}
+
+labels: dict[str, int] = {}
+
+def eval_symbol(c: str) -> str:
+  if c in labels:
+    return str(labels[c])
+
+  if c in constants:
+    return constants[c]
+
+  return c
+
+def eval_expr(expr: str) -> int:
+  expr = eval_symbol(expr)
+  return eval(expr, labels.copy()) # eval as Python expr