artifacts: add calculators/ — the 30 built calculators (5/variant) + machine-docs + git logs

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2026-06-16 15:39:42 +00:00
parent 64bc360fc0
commit bb85aa9f11
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"""Evaluator: walks an AST (from calc.parser) and returns int | float.
Result-type rule: if the result is whole-valued (no fractional part), return int;
otherwise return float. This means 4/2 → 2 (int) and 7/2 → 3.5 (float).
"""
from __future__ import annotations
from calc.parser import Num, BinOp, Unary, Node
class EvalError(Exception):
pass
def _normalize(v: int | float) -> int | float:
if isinstance(v, float) and v == int(v):
return int(v)
return v
def evaluate(node: Node) -> int | float:
if isinstance(node, Num):
return _normalize(node.value)
if isinstance(node, Unary):
val = evaluate(node.operand)
if node.op == '-':
return _normalize(-val)
raise EvalError(f"unknown unary operator: {node.op!r}")
if isinstance(node, BinOp):
left = evaluate(node.left)
right = evaluate(node.right)
if node.op == '+':
result = left + right
elif node.op == '-':
result = left - right
elif node.op == '*':
result = left * right
elif node.op == '/':
if right == 0:
raise EvalError("division by zero")
result = left / right
else:
raise EvalError(f"unknown operator: {node.op!r}")
return _normalize(result)
raise EvalError(f"unknown node type: {type(node).__name__}")

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from __future__ import annotations
from dataclasses import dataclass
from typing import Union
class LexError(Exception):
pass
@dataclass
class Token:
kind: str
value: Union[int, float, str, None]
def __repr__(self) -> str:
return f"{self.kind}({self.value!r})"
_SINGLE = {
'+': 'PLUS',
'-': 'MINUS',
'*': 'STAR',
'/': 'SLASH',
'(': 'LPAREN',
')': 'RPAREN',
}
def tokenize(src: str) -> list[Token]:
tokens: list[Token] = []
i = 0
n = len(src)
while i < n:
ch = src[i]
if ch in ' \t\n\r':
i += 1
continue
if ch in _SINGLE:
tokens.append(Token(_SINGLE[ch], ch))
i += 1
continue
if ch.isdigit() or ch == '.':
j = i
while j < n and (src[j].isdigit() or src[j] == '.'):
j += 1
raw = src[i:j]
value: Union[int, float] = float(raw) if '.' in raw else int(raw)
tokens.append(Token('NUMBER', value))
i = j
continue
raise LexError(f"unexpected character {ch!r} at position {i}")
tokens.append(Token('EOF', None))
return tokens

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"""Recursive-descent parser for arithmetic expressions.
AST node shapes:
Num(value) — a numeric literal; value is int or float
BinOp(op, left, right) — binary op; op is one of '+', '-', '*', '/'
Unary(op, operand) — unary minus; op is '-'
Grammar (precedence encoded by structure):
expr = term ( ('+' | '-') term )*
term = unary ( ('*' | '/') unary )*
unary = '-' unary | primary
primary= NUMBER | '(' expr ')'
"""
from __future__ import annotations
from dataclasses import dataclass
from typing import List, Union
from calc.lexer import Token
class ParseError(Exception):
pass
@dataclass
class Num:
value: Union[int, float]
def __repr__(self) -> str:
return f"Num({self.value!r})"
@dataclass
class BinOp:
op: str
left: "Node"
right: "Node"
def __repr__(self) -> str:
return f"BinOp({self.op!r}, {self.left!r}, {self.right!r})"
@dataclass
class Unary:
op: str
operand: "Node"
def __repr__(self) -> str:
return f"Unary({self.op!r}, {self.operand!r})"
Node = Union[Num, BinOp, Unary]
class _Parser:
def __init__(self, tokens: List[Token]) -> None:
self._tokens = tokens
self._pos = 0
def _peek(self) -> Token:
return self._tokens[self._pos]
def _advance(self) -> Token:
tok = self._tokens[self._pos]
self._pos += 1
return tok
def _expect(self, kind: str) -> Token:
tok = self._peek()
if tok.kind != kind:
raise ParseError(f"expected {kind}, got {tok.kind!r} ({tok.value!r})")
return self._advance()
def parse(self) -> Node:
if self._peek().kind == "EOF":
raise ParseError("empty input")
node = self._expr()
if self._peek().kind != "EOF":
tok = self._peek()
raise ParseError(f"unexpected token {tok.kind!r} ({tok.value!r})")
return node
def _expr(self) -> Node:
node = self._term()
while self._peek().kind in ("PLUS", "MINUS"):
op = self._advance().value
right = self._term()
node = BinOp(op, node, right)
return node
def _term(self) -> Node:
node = self._unary()
while self._peek().kind in ("STAR", "SLASH"):
op = self._advance().value
right = self._unary()
node = BinOp(op, node, right)
return node
def _unary(self) -> Node:
if self._peek().kind == "MINUS":
op = self._advance().value
operand = self._unary()
return Unary(op, operand)
return self._primary()
def _primary(self) -> Node:
tok = self._peek()
if tok.kind == "NUMBER":
self._advance()
return Num(tok.value)
if tok.kind == "LPAREN":
self._advance()
node = self._expr()
self._expect("RPAREN")
return node
raise ParseError(f"unexpected token {tok.kind!r} ({tok.value!r})")
def parse(tokens: List[Token]) -> Node:
"""Parse a token list (from lexer.tokenize) into an AST."""
return _Parser(tokens).parse()

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"""Tests for calc.evaluator (D1D3) and CLI (D4)."""
import subprocess
import sys
import unittest
from calc.lexer import tokenize
from calc.parser import parse
from calc.evaluator import EvalError, evaluate
def _eval(expr: str) -> int | float:
return evaluate(parse(tokenize(expr)))
class TestArithmetic(unittest.TestCase):
"""D1 — arithmetic, precedence, parens, unary minus."""
def test_addition(self):
self.assertEqual(_eval("2+3"), 5)
def test_subtraction(self):
self.assertEqual(_eval("10-4"), 6)
def test_multiplication(self):
self.assertEqual(_eval("3*4"), 12)
def test_precedence_mul_over_add(self):
self.assertEqual(_eval("2+3*4"), 14)
def test_precedence_parens(self):
self.assertEqual(_eval("(2+3)*4"), 20)
def test_left_assoc_sub(self):
self.assertEqual(_eval("8-3-2"), 3)
def test_unary_minus_leading(self):
self.assertEqual(_eval("-2+5"), 3)
def test_unary_minus_after_op(self):
self.assertEqual(_eval("2*-3"), -6)
class TestDivision(unittest.TestCase):
"""D2 — true division and EvalError on zero."""
def test_true_division(self):
self.assertEqual(_eval("7/2"), 3.5)
def test_division_by_zero(self):
with self.assertRaises(EvalError):
_eval("5/0")
def test_division_by_zero_not_bare(self):
"""EvalError, not ZeroDivisionError."""
try:
_eval("1/0")
self.fail("expected EvalError")
except EvalError:
pass
except ZeroDivisionError:
self.fail("bare ZeroDivisionError escaped")
class TestResultType(unittest.TestCase):
"""D3 — result type: whole-valued → int, non-whole → float."""
def test_whole_division_returns_int(self):
result = _eval("4/2")
self.assertEqual(result, 2)
self.assertIsInstance(result, int)
def test_non_whole_division_returns_float(self):
result = _eval("7/2")
self.assertEqual(result, 3.5)
self.assertIsInstance(result, float)
def test_integer_arithmetic_returns_int(self):
result = _eval("2+3*4")
self.assertEqual(result, 14)
self.assertIsInstance(result, int)
def test_print_whole_no_dot_zero(self):
self.assertEqual(str(_eval("4/2")), "2")
def test_print_non_whole_has_decimal(self):
self.assertEqual(str(_eval("7/2")), "3.5")
def test_float_literal_whole_normalizes_to_int(self):
result = _eval("4.0")
self.assertEqual(result, 4)
self.assertIsInstance(result, int)
def test_float_literal_trailing_dot_normalizes(self):
result = _eval("10.")
self.assertEqual(result, 10)
self.assertIsInstance(result, int)
def test_float_literal_zero_normalizes(self):
result = _eval("0.0")
self.assertEqual(result, 0)
self.assertIsInstance(result, int)
def test_unary_minus_float_normalizes(self):
result = _eval("-4.0")
self.assertEqual(result, -4)
self.assertIsInstance(result, int)
class TestCLI(unittest.TestCase):
"""D4 — CLI behaviour."""
def _run(self, expr: str):
return subprocess.run(
[sys.executable, "calc.py", expr],
capture_output=True, text=True
)
def test_cli_basic(self):
r = self._run("2+3*4")
self.assertEqual(r.returncode, 0)
self.assertEqual(r.stdout.strip(), "14")
def test_cli_parens(self):
r = self._run("(2+3)*4")
self.assertEqual(r.returncode, 0)
self.assertEqual(r.stdout.strip(), "20")
def test_cli_float_result(self):
r = self._run("7/2")
self.assertEqual(r.returncode, 0)
self.assertEqual(r.stdout.strip(), "3.5")
def test_cli_whole_division(self):
r = self._run("4/2")
self.assertEqual(r.returncode, 0)
self.assertEqual(r.stdout.strip(), "2")
def test_cli_divide_by_zero_nonzero_exit(self):
r = self._run("1/0")
self.assertNotEqual(r.returncode, 0)
self.assertGreater(len(r.stderr), 0)
self.assertEqual(r.stdout, "")
def test_cli_invalid_expr_nonzero_exit(self):
r = self._run("1 +")
self.assertNotEqual(r.returncode, 0)
self.assertGreater(len(r.stderr), 0)
self.assertEqual(r.stdout, "")
if __name__ == "__main__":
unittest.main()

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import unittest
from calc.lexer import tokenize, Token, LexError
def kinds(src):
return [t.kind for t in tokenize(src)]
def pairs(src):
return [(t.kind, t.value) for t in tokenize(src)]
class TestNumbers(unittest.TestCase):
def test_integer(self):
toks = tokenize("42")
self.assertEqual(toks, [Token('NUMBER', 42), Token('EOF', None)])
self.assertIsInstance(toks[0].value, int)
def test_float(self):
toks = tokenize("3.14")
self.assertEqual(toks[0], Token('NUMBER', 3.14))
self.assertIsInstance(toks[0].value, float)
def test_leading_dot(self):
toks = tokenize(".5")
self.assertAlmostEqual(toks[0].value, 0.5)
def test_trailing_dot(self):
toks = tokenize("10.")
self.assertEqual(toks[0].value, 10.0)
self.assertIsInstance(toks[0].value, float)
class TestOperatorsAndParens(unittest.TestCase):
def test_all_operators(self):
self.assertEqual(kinds("+"), ['PLUS', 'EOF'])
self.assertEqual(kinds("-"), ['MINUS', 'EOF'])
self.assertEqual(kinds("*"), ['STAR', 'EOF'])
self.assertEqual(kinds("/"), ['SLASH', 'EOF'])
self.assertEqual(kinds("("), ['LPAREN', 'EOF'])
self.assertEqual(kinds(")"), ['RPAREN', 'EOF'])
def test_expression_1_plus_2_star_3(self):
self.assertEqual(kinds("1+2*3"),
['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF'])
def test_expression_3_5_times_paren(self):
self.assertEqual(kinds("3.5*(1-2)"),
['NUMBER', 'STAR', 'LPAREN', 'NUMBER', 'MINUS', 'NUMBER', 'RPAREN', 'EOF'])
class TestWhitespaceAndErrors(unittest.TestCase):
def test_whitespace_between_tokens(self):
toks = tokenize(" 12 + 3 ")
self.assertEqual([(t.kind, t.value) for t in toks],
[('NUMBER', 12), ('PLUS', '+'), ('NUMBER', 3), ('EOF', None)])
def test_tabs_skipped(self):
self.assertEqual(kinds("1\t+\t2"), ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])
def test_invalid_at_raises(self):
with self.assertRaises(LexError) as ctx:
tokenize("1 @ 2")
self.assertIn('@', str(ctx.exception))
def test_invalid_dollar_raises(self):
with self.assertRaises(LexError):
tokenize("$")
def test_invalid_letter_raises(self):
with self.assertRaises(LexError):
tokenize("x")
def test_error_position_reported(self):
with self.assertRaises(LexError) as ctx:
tokenize("1 @ 2")
self.assertIn('2', str(ctx.exception)) # position 2
def test_complex_expression(self):
toks = tokenize("3.5*(1-2)")
expected = [
('NUMBER', 3.5), ('STAR', '*'), ('LPAREN', '('),
('NUMBER', 1), ('MINUS', '-'), ('NUMBER', 2),
('RPAREN', ')'), ('EOF', None),
]
self.assertEqual([(t.kind, t.value) for t in toks], expected)
if __name__ == '__main__':
unittest.main()

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"""Tests for calc.parser — assert on tree structure, not evaluation."""
import unittest
from calc.lexer import tokenize
from calc.parser import parse, ParseError, Num, BinOp, Unary
def p(src):
return parse(tokenize(src))
class TestPrecedence(unittest.TestCase):
"""D1 — * and / bind tighter than + and -."""
def test_add_mul(self):
# 1+2*3 => BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))
tree = p("1+2*3")
self.assertEqual(tree, BinOp('+', Num(1), BinOp('*', Num(2), Num(3))))
def test_mul_add(self):
# 2*3+4 => BinOp('+', BinOp('*', Num(2), Num(3)), Num(4))
tree = p("2*3+4")
self.assertEqual(tree, BinOp('+', BinOp('*', Num(2), Num(3)), Num(4)))
def test_sub_div(self):
# 10-6/2 => BinOp('-', Num(10), BinOp('/', Num(6), Num(2)))
tree = p("10-6/2")
self.assertEqual(tree, BinOp('-', Num(10), BinOp('/', Num(6), Num(2))))
class TestLeftAssociativity(unittest.TestCase):
"""D2 — same-precedence ops associate left."""
def test_sub_assoc(self):
# 8-3-2 => BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))
tree = p("8-3-2")
self.assertEqual(tree, BinOp('-', BinOp('-', Num(8), Num(3)), Num(2)))
def test_div_assoc(self):
# 8/4/2 => BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))
tree = p("8/4/2")
self.assertEqual(tree, BinOp('/', BinOp('/', Num(8), Num(4)), Num(2)))
def test_add_assoc(self):
# 1+2+3 => BinOp('+', BinOp('+', Num(1), Num(2)), Num(3))
tree = p("1+2+3")
self.assertEqual(tree, BinOp('+', BinOp('+', Num(1), Num(2)), Num(3)))
def test_mul_assoc(self):
# 2*3*4 => BinOp('*', BinOp('*', Num(2), Num(3)), Num(4))
tree = p("2*3*4")
self.assertEqual(tree, BinOp('*', BinOp('*', Num(2), Num(3)), Num(4)))
class TestParentheses(unittest.TestCase):
"""D3 — parens override precedence."""
def test_paren_add_mul(self):
# (1+2)*3 => BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))
tree = p("(1+2)*3")
self.assertEqual(tree, BinOp('*', BinOp('+', Num(1), Num(2)), Num(3)))
def test_nested_parens(self):
# ((2+3)) => BinOp('+', Num(2), Num(3)) -- outer parens just unwrap
tree = p("((2+3))")
self.assertEqual(tree, BinOp('+', Num(2), Num(3)))
def test_paren_single_num(self):
tree = p("(42)")
self.assertEqual(tree, Num(42))
class TestUnaryMinus(unittest.TestCase):
"""D4 — leading and nested unary minus."""
def test_unary_simple(self):
# -5 => Unary('-', Num(5))
tree = p("-5")
self.assertEqual(tree, Unary('-', Num(5)))
def test_unary_paren(self):
# -(1+2) => Unary('-', BinOp('+', Num(1), Num(2)))
tree = p("-(1+2)")
self.assertEqual(tree, Unary('-', BinOp('+', Num(1), Num(2))))
def test_mul_unary(self):
# 3 * -2 => BinOp('*', Num(3), Unary('-', Num(2)))
tree = p("3 * -2")
self.assertEqual(tree, BinOp('*', Num(3), Unary('-', Num(2))))
def test_double_unary(self):
# --5 => Unary('-', Unary('-', Num(5)))
tree = p("--5")
self.assertEqual(tree, Unary('-', Unary('-', Num(5))))
class TestErrors(unittest.TestCase):
"""D5 — malformed input raises ParseError."""
def test_trailing_op(self):
with self.assertRaises(ParseError):
p("1 +")
def test_unclosed_paren(self):
with self.assertRaises(ParseError):
p("(1")
def test_two_numbers(self):
with self.assertRaises(ParseError):
p("1 2")
def test_close_then_open(self):
with self.assertRaises(ParseError):
p(")(")
def test_empty_string(self):
with self.assertRaises(ParseError):
p("")
def test_only_paren(self):
with self.assertRaises(ParseError):
p("()")
if __name__ == "__main__":
unittest.main()