artifacts: add calculators/ — the 30 built calculators (5/variant) + machine-docs + git logs
This commit is contained in:
@@ -0,0 +1,26 @@
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from calc.parser import Num, BinOp, Unary
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class EvalError(Exception):
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pass
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def evaluate(node) -> int | float:
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if isinstance(node, Num):
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return node.value
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if isinstance(node, Unary):
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return -evaluate(node.operand)
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if isinstance(node, BinOp):
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left = evaluate(node.left)
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right = evaluate(node.right)
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if node.op == 'PLUS':
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return left + right
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if node.op == 'MINUS':
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return left - right
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if node.op == 'STAR':
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return left * right
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if node.op == 'SLASH':
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if right == 0:
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raise EvalError("division by zero")
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return left / right
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raise EvalError(f"unknown node: {node!r}")
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@@ -0,0 +1,52 @@
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import re
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from dataclasses import dataclass
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from typing import Union
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class LexError(Exception):
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pass
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@dataclass
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class Token:
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kind: str
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value: Union[int, float, None]
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def __repr__(self):
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return f"{self.kind}({self.value!r})"
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_NUMBER_RE = re.compile(r'\d+\.?\d*|\.\d+')
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_SINGLE = {
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'+': 'PLUS',
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'-': 'MINUS',
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'*': 'STAR',
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'/': 'SLASH',
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'(': 'LPAREN',
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')': 'RPAREN',
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}
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def tokenize(src: str) -> list:
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tokens = []
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i = 0
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while i < len(src):
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ch = src[i]
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if ch in ' \t':
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i += 1
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continue
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m = _NUMBER_RE.match(src, i)
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if m:
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raw = m.group()
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value = float(raw) if '.' in raw else int(raw)
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tokens.append(Token('NUMBER', value))
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i = m.end()
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continue
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if ch in _SINGLE:
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tokens.append(Token(_SINGLE[ch], None))
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i += 1
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continue
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raise LexError(f"unexpected character {ch!r} at position {i}")
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tokens.append(Token('EOF', None))
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return tokens
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@@ -0,0 +1,100 @@
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from dataclasses import dataclass
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from typing import Union
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class ParseError(Exception):
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pass
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@dataclass
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class Num:
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value: Union[int, float]
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def __repr__(self):
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return f"Num({self.value!r})"
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@dataclass
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class BinOp:
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op: str
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left: object
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right: object
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def __repr__(self):
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return f"BinOp({self.op!r}, {self.left!r}, {self.right!r})"
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@dataclass
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class Unary:
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op: str
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operand: object
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def __repr__(self):
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return f"Unary({self.op!r}, {self.operand!r})"
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def parse(tokens: list):
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"""Parse a token list into an AST.
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Grammar:
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expr → term (('+' | '-') term)*
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term → unary (('*' | '/') unary)*
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unary → '-' unary | primary
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primary → NUMBER | '(' expr ')'
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Returns the root Node. Raises ParseError on malformed input.
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"""
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pos = 0
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def peek():
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return tokens[pos]
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def consume(kind=None):
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nonlocal pos
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tok = tokens[pos]
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if kind and tok.kind != kind:
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raise ParseError(f"expected {kind}, got {tok.kind!r}")
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pos += 1
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return tok
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def expr():
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left = term()
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while peek().kind in ('PLUS', 'MINUS'):
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op = consume().kind
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right = term()
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left = BinOp(op, left, right)
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return left
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def term():
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left = unary()
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while peek().kind in ('STAR', 'SLASH'):
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op = consume().kind
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right = unary()
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left = BinOp(op, left, right)
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return left
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def unary():
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if peek().kind == 'MINUS':
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op = consume().kind
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operand = unary()
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return Unary(op, operand)
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return primary()
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def primary():
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tok = peek()
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if tok.kind == 'NUMBER':
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consume()
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return Num(tok.value)
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if tok.kind == 'LPAREN':
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consume()
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node = expr()
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if peek().kind != 'RPAREN':
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raise ParseError(f"expected ')', got {peek().kind!r}")
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consume()
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return node
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raise ParseError(f"unexpected token {tok.kind!r}")
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node = expr()
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if peek().kind != 'EOF':
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raise ParseError(f"unexpected token {peek().kind!r} after expression")
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return node
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@@ -0,0 +1,54 @@
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import unittest
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from calc.lexer import tokenize
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from calc.parser import parse
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from calc.evaluator import evaluate, EvalError
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def ev(s):
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return evaluate(parse(tokenize(s)))
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class TestArithmetic(unittest.TestCase):
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def test_add_mul_precedence(self):
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self.assertEqual(ev("2+3*4"), 14)
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def test_parens_override_precedence(self):
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self.assertEqual(ev("(2+3)*4"), 20)
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def test_left_assoc_subtraction(self):
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self.assertEqual(ev("8-3-2"), 3)
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def test_unary_minus_leading(self):
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self.assertEqual(ev("-2+5"), 3)
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def test_unary_minus_in_mul(self):
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self.assertEqual(ev("2*-3"), -6)
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class TestDivision(unittest.TestCase):
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def test_true_division(self):
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self.assertAlmostEqual(ev("7/2"), 3.5)
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def test_division_by_zero(self):
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with self.assertRaises(EvalError):
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ev("1/0")
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def test_division_by_zero_expr(self):
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with self.assertRaises(EvalError):
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ev("5/(3-3)")
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class TestResultType(unittest.TestCase):
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def test_whole_division_is_int(self):
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result = ev("4/2")
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self.assertEqual(result, 2)
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def test_non_whole_division_is_float(self):
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result = ev("7/2")
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self.assertIsInstance(result, float)
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self.assertAlmostEqual(result, 3.5)
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def test_integer_arithmetic_stays_int(self):
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result = ev("3+4")
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self.assertIsInstance(result, int)
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self.assertEqual(result, 7)
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@@ -0,0 +1,100 @@
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import unittest
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from calc.lexer import tokenize, Token, LexError
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def kinds(src):
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return [t.kind for t in tokenize(src)]
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def kind_value(src):
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return [(t.kind, t.value) for t in tokenize(src)]
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class TestNumbers(unittest.TestCase):
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def test_integer(self):
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tokens = tokenize("42")
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self.assertEqual(tokens[0], Token('NUMBER', 42))
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self.assertEqual(tokens[1], Token('EOF', None))
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def test_float(self):
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tokens = tokenize("3.14")
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self.assertIsInstance(tokens[0].value, float)
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self.assertAlmostEqual(tokens[0].value, 3.14)
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def test_leading_dot(self):
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tokens = tokenize(".5")
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self.assertEqual(tokens[0].kind, 'NUMBER')
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self.assertAlmostEqual(tokens[0].value, 0.5)
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def test_trailing_dot(self):
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tokens = tokenize("10.")
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self.assertEqual(tokens[0].kind, 'NUMBER')
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self.assertAlmostEqual(tokens[0].value, 10.0)
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class TestOperatorsAndParens(unittest.TestCase):
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def test_single_ops(self):
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self.assertEqual(kinds("+"), ['PLUS', 'EOF'])
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self.assertEqual(kinds("-"), ['MINUS', 'EOF'])
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self.assertEqual(kinds("*"), ['STAR', 'EOF'])
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self.assertEqual(kinds("/"), ['SLASH', 'EOF'])
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self.assertEqual(kinds("("), ['LPAREN', 'EOF'])
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self.assertEqual(kinds(")"), ['RPAREN', 'EOF'])
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def test_expression(self):
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self.assertEqual(kinds("1+2*3"), ['NUMBER', 'PLUS', 'NUMBER', 'STAR', 'NUMBER', 'EOF'])
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def test_paren_expression(self):
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self.assertEqual(kinds("3.5*(1-2)"),
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['NUMBER', 'STAR', 'LPAREN', 'NUMBER', 'MINUS', 'NUMBER', 'RPAREN', 'EOF'])
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class TestWhitespaceAndErrors(unittest.TestCase):
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def test_whitespace_skipped(self):
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self.assertEqual(kinds(" 12 + 3 "), ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])
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def test_tab_whitespace(self):
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self.assertEqual(kinds("1\t+\t2"), ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])
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def test_lex_error_at(self):
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with self.assertRaises(LexError) as ctx:
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tokenize("1 @ 2")
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self.assertIn('@', str(ctx.exception))
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def test_lex_error_dollar(self):
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with self.assertRaises(LexError):
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tokenize("$")
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def test_lex_error_letter(self):
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with self.assertRaises(LexError):
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tokenize("abc")
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def test_lex_error_position(self):
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with self.assertRaises(LexError) as ctx:
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tokenize("1 @ 2")
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self.assertIn('2', str(ctx.exception))
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class TestSpecificExamples(unittest.TestCase):
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"""Exact examples from the DoD."""
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def test_dod_42(self):
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toks = tokenize("42")
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self.assertEqual(toks[0].kind, 'NUMBER')
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self.assertEqual(toks[0].value, 42)
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self.assertEqual(toks[1].kind, 'EOF')
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def test_dod_spaced(self):
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self.assertEqual(kinds(" 12 + 3 "), ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])
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def test_dod_paren(self):
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self.assertEqual(kinds("3.5*(1-2)"),
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['NUMBER', 'STAR', 'LPAREN', 'NUMBER', 'MINUS', 'NUMBER', 'RPAREN', 'EOF'])
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def test_dod_lex_error(self):
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with self.assertRaises(LexError):
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tokenize("1 @ 2")
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if __name__ == '__main__':
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unittest.main()
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@@ -0,0 +1,107 @@
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import unittest
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from calc.lexer import tokenize
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from calc.parser import parse, ParseError, Num, BinOp, Unary
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def p(src):
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return parse(tokenize(src))
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class TestPrecedence(unittest.TestCase):
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def test_mul_tighter_than_add(self):
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# 1+2*3 → PLUS(1, STAR(2, 3)) NOT STAR(PLUS(1,2), 3)
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self.assertEqual(p('1+2*3'), BinOp('PLUS', Num(1), BinOp('STAR', Num(2), Num(3))))
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def test_mul_tighter_than_sub(self):
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# 2*3-1 → MINUS(STAR(2,3), 1)
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self.assertEqual(p('2*3-1'), BinOp('MINUS', BinOp('STAR', Num(2), Num(3)), Num(1)))
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def test_div_tighter_than_add(self):
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# 4/2+1 → PLUS(SLASH(4,2), 1)
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self.assertEqual(p('4/2+1'), BinOp('PLUS', BinOp('SLASH', Num(4), Num(2)), Num(1)))
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def test_div_tighter_than_sub(self):
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# 6-4/2 → MINUS(6, SLASH(4,2))
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self.assertEqual(p('6-4/2'), BinOp('MINUS', Num(6), BinOp('SLASH', Num(4), Num(2))))
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class TestLeftAssociativity(unittest.TestCase):
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def test_sub_left(self):
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# 8-3-2 → MINUS(MINUS(8,3), 2)
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self.assertEqual(p('8-3-2'), BinOp('MINUS', BinOp('MINUS', Num(8), Num(3)), Num(2)))
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def test_div_left(self):
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# 8/4/2 → SLASH(SLASH(8,4), 2)
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self.assertEqual(p('8/4/2'), BinOp('SLASH', BinOp('SLASH', Num(8), Num(4)), Num(2)))
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def test_add_left(self):
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# 1+2+3 → PLUS(PLUS(1,2), 3)
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self.assertEqual(p('1+2+3'), BinOp('PLUS', BinOp('PLUS', Num(1), Num(2)), Num(3)))
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def test_mul_left(self):
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# 2*3*4 → STAR(STAR(2,3), 4)
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self.assertEqual(p('2*3*4'), BinOp('STAR', BinOp('STAR', Num(2), Num(3)), Num(4)))
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class TestParentheses(unittest.TestCase):
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def test_paren_overrides_precedence(self):
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# (1+2)*3 → STAR(PLUS(1,2), 3) — plus is UNDER star
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self.assertEqual(p('(1+2)*3'), BinOp('STAR', BinOp('PLUS', Num(1), Num(2)), Num(3)))
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def test_paren_on_right(self):
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# 3*(1+2) → STAR(3, PLUS(1,2))
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self.assertEqual(p('3*(1+2)'), BinOp('STAR', Num(3), BinOp('PLUS', Num(1), Num(2))))
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def test_nested_parens(self):
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# ((2+3)) → PLUS(2,3)
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self.assertEqual(p('((2+3))'), BinOp('PLUS', Num(2), Num(3)))
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def test_single_number_in_parens(self):
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self.assertEqual(p('(42)'), Num(42))
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class TestUnaryMinus(unittest.TestCase):
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def test_leading_unary(self):
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self.assertEqual(p('-5'), Unary('MINUS', Num(5)))
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def test_unary_on_paren(self):
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# -(1+2) → UNARY(-, PLUS(1,2))
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self.assertEqual(p('-(1+2)'), Unary('MINUS', BinOp('PLUS', Num(1), Num(2))))
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def test_unary_in_mul(self):
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# 3 * -2 → STAR(3, UNARY(-,2))
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self.assertEqual(p('3 * -2'), BinOp('STAR', Num(3), Unary('MINUS', Num(2))))
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def test_double_unary(self):
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# --5 → UNARY(-,UNARY(-,5))
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self.assertEqual(p('--5'), Unary('MINUS', Unary('MINUS', Num(5))))
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def test_unary_in_add(self):
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# 1 + -2 → PLUS(1, UNARY(-,2))
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self.assertEqual(p('1 + -2'), BinOp('PLUS', Num(1), Unary('MINUS', Num(2))))
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class TestErrors(unittest.TestCase):
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def test_trailing_operator(self):
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with self.assertRaises(ParseError):
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p('1 +')
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def test_unclosed_paren(self):
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with self.assertRaises(ParseError):
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p('(1')
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def test_consecutive_numbers(self):
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with self.assertRaises(ParseError):
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p('1 2')
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def test_mismatched_parens_close_first(self):
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with self.assertRaises(ParseError):
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p(')(')
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def test_empty_string(self):
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with self.assertRaises(ParseError):
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p('')
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if __name__ == '__main__':
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unittest.main()
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