🐐 Fractions

centvrion/ast_nodes.py

@@ -1,9 +1,11 @@
 import re
 import random
+from fractions import Fraction
 
 from rply.token import BaseBox
 
-from centvrion.values import Val, ValInt, ValStr, ValBool, ValList, ValNul, ValFunc
+from centvrion.errors import CentvrionError
+from centvrion.values import Val, ValInt, ValStr, ValBool, ValList, ValNul, ValFunc, ValFrac
 
 NUMERALS = {
   "I": 1,
@@ -34,7 +36,7 @@ def rep_join(l):
 OP_STR = {
   "SYMBOL_PLUS": "+", "SYMBOL_MINUS": "-",
   "SYMBOL_TIMES": "*", "SYMBOL_DIVIDE": "/",
-  "SYMBOL_COLON": ":",
+  "SYMBOL_AMPERSAND": "&",
   "KEYWORD_EST": "EST", "KEYWORD_MINVS": "MINVS",
   "KEYWORD_PLVS": "PLVS", "KEYWORD_ET": "ET", "KEYWORD_AVT": "AVT",
 }
@@ -42,12 +44,12 @@ OP_STR = {
 def single_num_to_int(i, m):
   if i[-1] == "_":
     if not m:
-      raise ValueError(
+      raise CentvrionError(
         "Cannot calculate numbers above 3999 without 'MAGNVM' module"
       )
 
     if i[0] != "I":
-      raise ValueError(
+      raise CentvrionError(
         "Cannot use 'I' with thousands operator, use 'M' instead"
       )
 
@@ -58,16 +60,16 @@ def single_num_to_int(i, m):
 def num_to_int(n, m, s=False):
   if n.startswith("-"):
     if not s:
-      raise ValueError("Cannot use negative numbers without 'SVBNVLLA' module")
+      raise CentvrionError("Cannot use negative numbers without 'SVBNVLLA' module")
     return -num_to_int(n[1:], m, s)
   chars = re.findall(r"[IVXLCDM]_*", n)
   if ''.join(chars) != n:
-    raise ValueError("Invalid numeral", n)
+    raise CentvrionError(f"Invalid numeral: {n!r}")
   nums = [single_num_to_int(i, m) for i in chars]
   new_nums = nums.copy()
   for x, num in enumerate(nums[:-3]):
     if all(num == nums[x+i] for i in range(0,4)):
-      raise ValueError(n, "is not a valid roman numeral")
+      raise CentvrionError(f"{n!r} is not a valid roman numeral")
 
   while True:
     for x, num in enumerate(nums[:-1]):
@@ -77,7 +79,7 @@ def num_to_int(n, m, s=False):
           new_nums[x+1] = 0
           break
         else:
-          raise ValueError(n, "is not a valid roman numeral")
+          raise CentvrionError(f"{n!r} is not a valid roman numeral")
 
     if new_nums != nums:
       nums = [i for i in new_nums if i != 0]
@@ -86,18 +88,18 @@ def num_to_int(n, m, s=False):
       break
 
   if nums != sorted(nums)[::-1]:
-    raise Exception(n, "is not a valid roman numeral")
+    raise CentvrionError(f"{n!r} is not a valid roman numeral")
 
   return sum(nums)
 
 def int_to_num(n, m, s=False):
   if n < 0:
     if not s:
-      raise ValueError("Cannot display negative numbers without 'SVBNVLLA' module")
+      raise CentvrionError("Cannot display negative numbers without 'SVBNVLLA' module")
     return "-" + int_to_num(-n, m, s)
   if n > 3999:
     if not m:
-      raise ValueError(
+      raise CentvrionError(
         "Cannot display numbers above 3999 without 'MAGNVM' module"
       )
     thousands_chars = re.findall(r"[IVXLCDM]_*", int_to_num(n//1000, m, s))
@@ -123,6 +125,8 @@ def make_string(val, magnvm=False, svbnvlla=False):
     return val.value()
   elif isinstance(val, ValInt):
     return int_to_num(val.value(), magnvm, svbnvlla)
+  elif isinstance(val, ValFrac):
+    return fraction_to_frac(val.value(), magnvm, svbnvlla)
   elif isinstance(val, ValBool):
     return "VERVS" if val.value() else "FALSVS"
   elif isinstance(val, ValNul):
@@ -131,7 +135,62 @@ def make_string(val, magnvm=False, svbnvlla=False):
     inner = ' '.join(make_string(i, magnvm, svbnvlla) for i in val.value())
     return f"[{inner}]"
   else:
-    raise TypeError(f"Cannot display {val!r}")
+    raise CentvrionError(f"Cannot display {val!r}")
+
+FRAC_SYMBOLS = [("S", 6), (":", 2), (".", 1)]
+
+def frac_to_fraction(s, magnvm=False, svbnvlla=False):
+  match = re.match(r'^([IVXLCDM][IVXLCDM_]*)(.*)', s)
+  if match:
+    int_str, frac_str = match.group(1), match.group(2)
+    total = Fraction(num_to_int(int_str, magnvm, svbnvlla))
+  else:
+    total = Fraction(0)
+    frac_str = s
+
+  for level_idx, level in enumerate(frac_str.split('|')):
+    divisor = 12 ** (level_idx + 1)
+    level_val = 0
+    prev_weight = 12
+    for ch in level:
+      weight = next((w for sym, w in FRAC_SYMBOLS if sym == ch), None)
+      if weight is None:
+        raise CentvrionError(f"Invalid fraction symbol: {ch!r}")
+      if weight > prev_weight:
+        raise CentvrionError("Fraction symbols must be written highest to lowest")
+      prev_weight = weight
+      level_val += weight
+    if level_val >= 12:
+      raise CentvrionError("Fraction level value must be less than 1 (< 12/12)")
+    total += Fraction(level_val, divisor)
+
+  return total
+
+def fraction_to_frac(f, magnvm=False, svbnvlla=False):
+  if f < 0:
+    if not svbnvlla:
+      raise CentvrionError("Cannot display negative fractions without 'SVBNVLLA' module")
+    return "-" + fraction_to_frac(-f, magnvm, svbnvlla)
+
+  integer_part = int(f)
+  remainder = f - integer_part
+  int_str = int_to_num(integer_part, magnvm, svbnvlla) if integer_part > 0 else ""
+
+  levels = []
+  current = remainder
+  for _ in range(6):
+    if current == 0:
+      break
+    current = current * 12
+    level_int = int(current)
+    current = current - level_int
+    s_count = level_int // 6
+    remaining = level_int % 6
+    colon_count = remaining // 2
+    dot_count = remaining % 2
+    levels.append("S" * s_count + ":" * colon_count + "." * dot_count)
+
+  return int_str + "|".join(levels)
 
 
 class Node(BaseBox):
@@ -200,6 +259,8 @@ class DataRangeArray(Node):
   def _eval(self, vtable):
     vtable, from_val = self.from_value.eval(vtable)
     vtable, to_val = self.to_value.eval(vtable)
+    if not isinstance(from_val, ValInt) or not isinstance(to_val, ValInt):
+      raise CentvrionError("Range bounds must be numbers")
     return vtable, ValList([ValInt(i) for i in range(from_val.value(), to_val.value())])
 
 
@@ -237,6 +298,27 @@ class Numeral(Node):
     return vtable, ValInt(num_to_int(self.value, "MAGNVM" in vtable["#modules"], "SVBNVLLA" in vtable["#modules"]))
 
 
+class Fractio(Node):
+  def __init__(self, value) -> None:
+    self.value = value
+
+  def __eq__(self, other):
+    return type(self) == type(other) and self.value == other.value
+
+  def __repr__(self):
+    return f"Fractio({self.value!r})"
+
+  def print(self):
+    return self.value
+
+  def _eval(self, vtable):
+    if "FRACTIO" not in vtable["#modules"]:
+      raise CentvrionError("Cannot use fraction literals without 'FRACTIO' module")
+    m = "MAGNVM" in vtable["#modules"]
+    s = "SVBNVLLA" in vtable["#modules"]
+    return vtable, ValFrac(frac_to_fraction(self.value, m, s))
+
+
 class Bool(Node):
   def __init__(self, value) -> None:
     self.value = value
@@ -282,6 +364,8 @@ class ID(Node):
     return self.name
 
   def _eval(self, vtable):
+    if self.name not in vtable:
+      raise CentvrionError(f"Undefined variable: {self.name}")
     return vtable, vtable[self.name]
 
 
@@ -325,10 +409,15 @@ class DesignaIndex(Node):
   def _eval(self, vtable):
     vtable, index = self.index.eval(vtable)
     vtable, val = self.value.eval(vtable)
+    if self.id.name not in vtable:
+      raise CentvrionError(f"Undefined variable: {self.id.name}")
+    target = vtable[self.id.name]
+    if not isinstance(target, ValList):
+      raise CentvrionError(f"{self.id.name} is not an array")
     i = index.value()
-    lst = list(vtable[self.id.name].value())
+    lst = list(target.value())
     if i < 1 or i > len(lst):
-      raise IndexError(f"Index {i} out of range for array of length {len(lst)}")
+      raise CentvrionError(f"Index {i} out of range for array of length {len(lst)}")
     lst[i - 1] = val
     vtable[self.id.name] = ValList(lst)
     return vtable, ValNul()
@@ -440,29 +529,49 @@ class BinOp(Node):
     match self.op:
       case "SYMBOL_PLUS":
         if isinstance(lv, str) or isinstance(rv, str):
-          raise TypeError("Use : for string concatenation, not +")
+          raise CentvrionError("Use & for string concatenation, not +")
+        if isinstance(lv, list) or isinstance(rv, list):
+          raise CentvrionError("Cannot use + on arrays")
         if lv is None and rv is None:
           return vtable, ValNul()
-        return vtable, ValInt((lv or 0) + (rv or 0))
-      case "SYMBOL_COLON":
+        result = (lv or 0) + (rv or 0)
+        return vtable, ValFrac(result) if isinstance(result, Fraction) else ValInt(result)
+      case "SYMBOL_AMPERSAND":
         magnvm = "MAGNVM" in vtable["#modules"]
         svbnvlla = "SVBNVLLA" in vtable["#modules"]
         def _coerce(v):
           if v is None: return ""
           if isinstance(v, bool): return "VERITAS" if v else "FALSITAS"
           if isinstance(v, int): return int_to_num(v, magnvm, svbnvlla)
+          if isinstance(v, Fraction): return fraction_to_frac(v, magnvm, svbnvlla)
+          if isinstance(v, list): return make_string(ValList(v), magnvm, svbnvlla)
           return v
         return vtable, ValStr(_coerce(lv) + _coerce(rv))
       case "SYMBOL_MINUS":
-        return vtable, ValInt((lv or 0) - (rv or 0))
+        if isinstance(lv, (str, list)) or isinstance(rv, (str, list)):
+          raise CentvrionError("Cannot use - on strings or arrays")
+        result = (lv or 0) - (rv or 0)
+        return vtable, ValFrac(result) if isinstance(result, Fraction) else ValInt(result)
       case "SYMBOL_TIMES":
-        return vtable, ValInt((lv or 0) * (rv or 0))
+        if isinstance(lv, (str, list)) or isinstance(rv, (str, list)):
+          raise CentvrionError("Cannot use * on strings or arrays")
+        result = (lv or 0) * (rv or 0)
+        return vtable, ValFrac(result) if isinstance(result, Fraction) else ValInt(result)
       case "SYMBOL_DIVIDE":
-        # TODO: Fractio
+        if isinstance(lv, (str, list)) or isinstance(rv, (str, list)):
+          raise CentvrionError("Cannot use / on strings or arrays")
+        if (rv or 0) == 0:
+          raise CentvrionError("Division by zero")
+        if isinstance(lv, Fraction) or isinstance(rv, Fraction) or "FRACTIO" in vtable["#modules"]:
+          return vtable, ValFrac(Fraction(lv or 0) / Fraction(rv or 0))
         return vtable, ValInt((lv or 0) // (rv or 0))
       case "KEYWORD_MINVS":
+        if isinstance(lv, (str, list)) or isinstance(rv, (str, list)):
+          raise CentvrionError("Cannot compare strings or arrays with MINVS")
         return vtable, ValBool((lv or 0) < (rv or 0))
       case "KEYWORD_PLVS":
+        if isinstance(lv, (str, list)) or isinstance(rv, (str, list)):
+          raise CentvrionError("Cannot compare strings or arrays with PLVS")
         return vtable, ValBool((lv or 0) > (rv or 0))
       case "KEYWORD_EST":
         return vtable, ValBool(lv == rv)
@@ -489,8 +598,10 @@ class UnaryMinus(Node):
 
   def _eval(self, vtable):
     if "SVBNVLLA" not in vtable["#modules"]:
-      raise ValueError("Cannot use unary minus without 'SVBNVLLA' module")
+      raise CentvrionError("Cannot use unary minus without 'SVBNVLLA' module")
     vtable, val = self.expr.eval(vtable)
+    if not isinstance(val, ValInt):
+      raise CentvrionError("Unary minus requires a number")
     return vtable, ValInt(-val.value())
 
 
@@ -529,10 +640,14 @@ class ArrayIndex(Node):
   def _eval(self, vtable):
     vtable, array = self.array.eval(vtable)
     vtable, index = self.index.eval(vtable)
+    if not isinstance(array, ValList):
+      raise CentvrionError("Cannot index a non-array value")
+    if not isinstance(index, ValInt):
+      raise CentvrionError("Array index must be a number")
     i = index.value()
     lst = array.value()
     if i < 1 or i > len(lst):
-      raise IndexError(f"Index {i} out of range for array of length {len(lst)}")
+      raise CentvrionError(f"Index {i} out of range for array of length {len(lst)}")
     return vtable, lst[i - 1]
 
 
@@ -628,6 +743,8 @@ class PerStatement(Node):
 
   def _eval(self, vtable):
     vtable, array = self.data_list.eval(vtable)
+    if not isinstance(array, ValList):
+      raise CentvrionError("PER requires an array")
     variable_name = self.variable_name.name
     last_val = ValNul()
     for item in array:
@@ -662,9 +779,13 @@ class Invoca(Node):
 
   def _eval(self, vtable):
     params = [p.eval(vtable)[1] for p in self.parameters]
+    if self.name.name not in vtable:
+      raise CentvrionError(f"Undefined function: {self.name.name}")
     func = vtable[self.name.name]
+    if not isinstance(func, ValFunc):
+      raise CentvrionError(f"{self.name.name} is not a function")
     if len(params) != len(func.params):
-      raise TypeError(
+      raise CentvrionError(
         f"{self.name.name} expects {len(func.params)} argument(s), got {len(params)}"
       )
     func_vtable = vtable.copy()
@@ -702,7 +823,11 @@ class BuiltIn(Node):
 
     match self.builtin:
       case "AVDI_NVMERVS":
-        return vtable, ValInt(num_to_int(input(), magnvm, svbnvlla))
+        raw = input()
+        try:
+          return vtable, ValInt(num_to_int(raw, magnvm, svbnvlla))
+        except ValueError:
+          raise CentvrionError(f"Invalid numeral input: {raw!r}")
       case "AVDI":
         return vtable, ValStr(input())
       case "DICE":
@@ -716,17 +841,25 @@ class BuiltIn(Node):
         return vtable, ValNul()
       case "FORTIS_NVMERVS":
         if "FORS" not in vtable["#modules"]:
-          raise ValueError(
-            "Cannot use 'FORTIS_NVMERVS' without module 'FORS'"
-          )
-        return vtable, ValInt(random.randint(params[0].value(), params[1].value()))
+          raise CentvrionError("Cannot use 'FORTIS_NVMERVS' without module 'FORS'")
+        a, b = params[0].value(), params[1].value()
+        if not isinstance(a, int) or not isinstance(b, int):
+          raise CentvrionError("FORTIS_NVMERVS requires two numbers")
+        if a > b:
+          raise CentvrionError(f"FORTIS_NVMERVS: first argument ({a}) must be ≤ second ({b})")
+        return vtable, ValInt(random.randint(a, b))
       case "FORTIS_ELECTIONIS":
         if "FORS" not in vtable["#modules"]:
-          raise ValueError(
-            "Cannot use 'FORTIS_ELECTIONIS' without module 'FORS'"
-          )
-        return vtable, params[0].value()[random.randint(0, len(params[0].value()) - 1)]
+          raise CentvrionError("Cannot use 'FORTIS_ELECTIONIS' without module 'FORS'")
+        if not isinstance(params[0], ValList):
+          raise CentvrionError("FORTIS_ELECTIONIS requires an array")
+        lst = params[0].value()
+        if len(lst) == 0:
+          raise CentvrionError("FORTIS_ELECTIONIS: cannot select from an empty array")
+        return vtable, lst[random.randint(0, len(lst) - 1)]
       case "LONGITVDO":
+        if not isinstance(params[0], ValList):
+          raise CentvrionError("LONGITVDO requires an array")
         return vtable, ValInt(len(params[0].value()))
       case _:
         raise NotImplementedError(self.builtin)