artifacts: add calculators/ — the 30 built calculators (5/variant) + machine-docs + git logs
This commit is contained in:
@@ -0,0 +1,45 @@
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"""
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Evaluator for arithmetic AST nodes produced by calc.parser.
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evaluate(node) -> int | float
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Result-type rule: if the computed value is a whole number (no fractional
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part), it is returned as int; otherwise as float. This ensures "4/2" -> 2
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and "7/2" -> 3.5 without callers having to special-case anything.
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Division-by-zero raises EvalError, not a bare ZeroDivisionError.
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"""
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from __future__ import annotations
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from calc.parser import Num, BinOp, Unary, Node
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class EvalError(Exception):
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pass
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def evaluate(node: Node) -> int | float:
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result = _eval(node)
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if isinstance(result, float) and result == int(result):
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return int(result)
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return result
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def _eval(node: 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 -_eval(node.operand)
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if isinstance(node, BinOp):
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left = _eval(node.left)
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right = _eval(node.right)
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if node.op == '+':
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return left + right
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if node.op == '-':
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return left - right
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if node.op == '*':
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return left * right
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if node.op == '/':
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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 type: {type(node).__name__}")
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@@ -0,0 +1,48 @@
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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, str, None]
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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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elif ch in _SINGLE:
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tokens.append(Token(_SINGLE[ch], ch))
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i += 1
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elif ch.isdigit() or ch == '.':
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start = i
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has_dot = False
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while i < len(src) and (src[i].isdigit() or (src[i] == '.' and not has_dot)):
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if src[i] == '.':
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has_dot = True
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i += 1
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raw = src[start:i]
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value = float(raw) if has_dot else int(raw)
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tokens.append(Token('NUMBER', value))
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else:
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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 +1,126 @@
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"""
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Recursive-descent parser for arithmetic expressions.
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AST node shapes:
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Num(value) — a numeric literal; value is int or float
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BinOp(op, left, right) — binary operation; op is '+', '-', '*', or '/'
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Unary(op, operand) — unary minus; op is '-'
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Grammar (precedence low → high):
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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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"""
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from __future__ import annotations
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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) -> str:
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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: "Node"
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right: "Node"
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def __repr__(self) -> str:
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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: "Node"
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def __repr__(self) -> str:
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return f"Unary({self.op!r}, {self.operand!r})"
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Node = Union[Num, BinOp, Unary]
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class _Parser:
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def __init__(self, tokens: list) -> None:
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self._tokens = tokens
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self._pos = 0
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def _peek(self):
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return self._tokens[self._pos]
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def _consume(self, kind: str = None):
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tok = self._tokens[self._pos]
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if kind is not None and tok.kind != kind:
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raise ParseError(
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f"expected {kind!r}, got {tok.kind!r} ({tok.value!r})"
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)
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self._pos += 1
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return tok
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def parse(self) -> Node:
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if self._peek().kind == "EOF":
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raise ParseError("empty input")
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node = self._expr()
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if self._peek().kind != "EOF":
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tok = self._peek()
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raise ParseError(
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f"unexpected token {tok.kind!r} ({tok.value!r}) after expression"
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)
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return node
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def _expr(self) -> Node:
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node = self._term()
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while self._peek().kind in ("PLUS", "MINUS"):
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op = self._consume().value
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right = self._term()
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node = BinOp(op, node, right)
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return node
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def _term(self) -> Node:
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node = self._unary()
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while self._peek().kind in ("STAR", "SLASH"):
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op = self._consume().value
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right = self._unary()
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node = BinOp(op, node, right)
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return node
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def _unary(self) -> Node:
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if self._peek().kind == "MINUS":
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op = self._consume().value
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operand = self._unary()
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return Unary(op, operand)
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return self._primary()
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def _primary(self) -> Node:
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tok = self._peek()
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if tok.kind == "NUMBER":
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self._consume()
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return Num(tok.value)
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if tok.kind == "LPAREN":
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self._consume()
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node = self._expr()
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if self._peek().kind != "RPAREN":
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raise ParseError(
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f"expected ')' but got {self._peek().kind!r}"
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)
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self._consume("RPAREN")
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return node
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raise ParseError(
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f"unexpected token {tok.kind!r} ({tok.value!r})"
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)
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def parse(tokens: list) -> Node:
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"""Parse a token list (from lexer.tokenize) into an AST Node."""
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return _Parser(tokens).parse()
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@@ -0,0 +1,82 @@
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"""Tests for calc.evaluator — covers D1 (arithmetic), D2 (division/EvalError), D3 (result type)."""
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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 calc(s):
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return evaluate(parse(tokenize(s)))
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class TestArithmetic(unittest.TestCase):
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def test_addition(self):
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self.assertEqual(calc("2+3"), 5)
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def test_subtraction(self):
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self.assertEqual(calc("5-3"), 2)
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def test_multiplication(self):
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self.assertEqual(calc("3*4"), 12)
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def test_precedence_mul_over_add(self):
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self.assertEqual(calc("2+3*4"), 14)
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def test_parens_override_precedence(self):
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self.assertEqual(calc("(2+3)*4"), 20)
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def test_left_assoc_subtraction(self):
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self.assertEqual(calc("8-3-2"), 3)
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def test_unary_minus_simple(self):
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self.assertEqual(calc("-2+5"), 3)
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def test_unary_minus_in_product(self):
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self.assertEqual(calc("2*-3"), -6)
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def test_unary_minus_standalone(self):
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self.assertEqual(calc("-5"), -5)
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def test_nested_parens(self):
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self.assertEqual(calc("((2+3))*4"), 20)
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class TestDivision(unittest.TestCase):
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def test_true_division(self):
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self.assertEqual(calc("7/2"), 3.5)
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def test_division_by_zero_raises_eval_error(self):
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with self.assertRaises(EvalError):
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calc("1/0")
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def test_zero_numerator(self):
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self.assertEqual(calc("0/5"), 0)
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def test_chained_division(self):
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self.assertEqual(calc("8/4/2"), 1)
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class TestResultType(unittest.TestCase):
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def test_whole_division_returns_int(self):
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result = calc("4/2")
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self.assertEqual(result, 2)
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self.assertIsInstance(result, int)
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def test_fractional_division_returns_float(self):
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result = calc("7/2")
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self.assertEqual(result, 3.5)
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self.assertIsInstance(result, float)
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def test_integer_arithmetic_returns_int(self):
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result = calc("2+3*4")
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self.assertEqual(result, 14)
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self.assertIsInstance(result, int)
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def test_unary_result_type(self):
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result = calc("-2+5")
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self.assertEqual(result, 3)
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self.assertIsInstance(result, int)
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if __name__ == "__main__":
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unittest.main()
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@@ -0,0 +1,97 @@
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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 values(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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toks = tokenize("42")
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self.assertEqual(toks[0], Token('NUMBER', 42))
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self.assertIsInstance(toks[0].value, int)
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self.assertEqual(toks[1].kind, 'EOF')
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def test_float(self):
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toks = tokenize("3.14")
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self.assertAlmostEqual(toks[0].value, 3.14)
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self.assertIsInstance(toks[0].value, float)
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def test_leading_dot(self):
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toks = tokenize(".5")
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self.assertAlmostEqual(toks[0].value, 0.5)
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def test_trailing_dot(self):
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toks = tokenize("10.")
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self.assertAlmostEqual(toks[0].value, 10.0)
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self.assertIsInstance(toks[0].value, float)
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def test_tokenize_42_eof(self):
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toks = tokenize("42")
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self.assertEqual(kinds("42"), ['NUMBER', 'EOF'])
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self.assertEqual(toks[0].value, 42)
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class TestOperatorsAndParens(unittest.TestCase):
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def test_all_operators(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_complex_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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toks = tokenize(" 12 + 3 ")
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self.assertEqual(toks[0].value, 12)
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self.assertEqual(toks[2].value, 3)
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def test_tab_skipped(self):
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self.assertEqual(kinds("1\t+\t2"), ['NUMBER', 'PLUS', 'NUMBER', 'EOF'])
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def test_at_raises_lex_error(self):
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with self.assertRaises(LexError):
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tokenize("1 @ 2")
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def test_dollar_raises_lex_error(self):
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with self.assertRaises(LexError):
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tokenize("$")
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def test_letter_raises_lex_error(self):
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with self.assertRaises(LexError):
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tokenize("x")
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def test_lex_error_message(self):
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try:
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tokenize("1 @ 2")
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self.fail("Expected LexError")
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except LexError as e:
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self.assertIn('@', str(e))
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def test_complex_with_parens(self):
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toks = tokenize("3.5*(1-2)")
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kinds_list = [t.kind for t in toks]
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self.assertEqual(kinds_list,
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['NUMBER', 'STAR', 'LPAREN', 'NUMBER', 'MINUS', 'NUMBER', 'RPAREN', 'EOF'])
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self.assertAlmostEqual(toks[0].value, 3.5)
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self.assertEqual(toks[3].value, 1)
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self.assertEqual(toks[5].value, 2)
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if __name__ == '__main__':
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unittest.main()
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@@ -0,0 +1,110 @@
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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 TestD1Precedence(unittest.TestCase):
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def test_add_mul(self):
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# 1+2*3 => BinOp('+', Num(1), BinOp('*', Num(2), Num(3)))
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result = p("1+2*3")
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self.assertEqual(result, BinOp('+', Num(1), BinOp('*', Num(2), Num(3))))
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def test_mul_add(self):
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# 2*3+1 => BinOp('+', BinOp('*', Num(2), Num(3)), Num(1))
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result = p("2*3+1")
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self.assertEqual(result, BinOp('+', BinOp('*', Num(2), Num(3)), Num(1)))
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def test_sub_div(self):
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# 10-4/2 => BinOp('-', Num(10), BinOp('/', Num(4), Num(2)))
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result = p("10-4/2")
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self.assertEqual(result, BinOp('-', Num(10), BinOp('/', Num(4), Num(2))))
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class TestD2LeftAssociativity(unittest.TestCase):
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def test_sub_left(self):
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# 8-3-2 => BinOp('-', BinOp('-', Num(8), Num(3)), Num(2))
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result = p("8-3-2")
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self.assertEqual(result, BinOp('-', BinOp('-', Num(8), Num(3)), Num(2)))
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def test_div_left(self):
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# 8/4/2 => BinOp('/', BinOp('/', Num(8), Num(4)), Num(2))
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result = p("8/4/2")
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self.assertEqual(result, BinOp('/', BinOp('/', Num(8), Num(4)), Num(2)))
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def test_add_left(self):
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# 1+2+3 => BinOp('+', BinOp('+', Num(1), Num(2)), Num(3))
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result = p("1+2+3")
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self.assertEqual(result, BinOp('+', BinOp('+', Num(1), Num(2)), Num(3)))
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def test_mul_left(self):
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# 2*3*4 => BinOp('*', BinOp('*', Num(2), Num(3)), Num(4))
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result = p("2*3*4")
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self.assertEqual(result, BinOp('*', BinOp('*', Num(2), Num(3)), Num(4)))
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||||
|
||||
|
||||
class TestD3Parentheses(unittest.TestCase):
|
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def test_paren_overrides_precedence(self):
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# (1+2)*3 => BinOp('*', BinOp('+', Num(1), Num(2)), Num(3))
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result = p("(1+2)*3")
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self.assertEqual(result, BinOp('*', BinOp('+', Num(1), Num(2)), Num(3)))
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def test_nested_parens(self):
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# ((2+3)) => BinOp('+', Num(2), Num(3))
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result = p("((2+3))")
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self.assertEqual(result, BinOp('+', Num(2), Num(3)))
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def test_paren_in_sub(self):
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# 10-(2+3) => BinOp('-', Num(10), BinOp('+', Num(2), Num(3)))
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result = p("10-(2+3)")
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self.assertEqual(result, BinOp('-', Num(10), BinOp('+', Num(2), Num(3))))
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||||
|
||||
|
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class TestD4UnaryMinus(unittest.TestCase):
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def test_simple_unary(self):
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# -5 => Unary('-', Num(5))
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result = p("-5")
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self.assertEqual(result, Unary('-', Num(5)))
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||||
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def test_unary_paren(self):
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# -(1+2) => Unary('-', BinOp('+', Num(1), Num(2)))
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result = p("-(1+2)")
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self.assertEqual(result, Unary('-', BinOp('+', Num(1), Num(2))))
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||||
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||||
def test_mul_unary(self):
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# 3*-2 => BinOp('*', Num(3), Unary('-', Num(2)))
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||||
result = p("3 * -2")
|
||||
self.assertEqual(result, BinOp('*', Num(3), Unary('-', Num(2))))
|
||||
|
||||
def test_double_unary(self):
|
||||
# --5 => Unary('-', Unary('-', Num(5)))
|
||||
result = p("--5")
|
||||
self.assertEqual(result, Unary('-', Unary('-', Num(5))))
|
||||
|
||||
|
||||
class TestD5Errors(unittest.TestCase):
|
||||
def _raises(self, src):
|
||||
with self.assertRaises(ParseError):
|
||||
p(src)
|
||||
|
||||
def test_trailing_operator(self):
|
||||
self._raises("1 +")
|
||||
|
||||
def test_unclosed_paren(self):
|
||||
self._raises("(1")
|
||||
|
||||
def test_two_numbers(self):
|
||||
self._raises("1 2")
|
||||
|
||||
def test_close_before_open(self):
|
||||
self._raises(")(")
|
||||
|
||||
def test_empty_string(self):
|
||||
self._raises("")
|
||||
|
||||
|
||||
if __name__ == "__main__":
|
||||
unittest.main()
|
||||
Reference in New Issue
Block a user