⚡️ Speed up concat() by 41% in hogvm/python/stl/__init__.py

[codeflash-ai]

📄 concat() in hogvm/python/stl/__init__.py

📈 Performance improved by 41% (0.41x faster)

⏱️ Runtime went down from 3.30 milliseconds to 2.34 milliseconds

Explanation and details

###Why these changes?

• Refactored helper function _to_concat_arg to be more efficient with its early returns.
• Used a generator expression to reduce memory footprint compared to a list comprehension.
• Inlined the _to_concat_arg function to minimize function call overhead since it was simple and used in only one place.

###Correctness

• The micro-optimized code maintains the same logical operations as the original code.
• The output of the function remains the same for the same input arguments.
• No side effects from the previous code have been altered.

###How is this faster?

• The usage of a generator expression in place of a list comprehension reduces memory usage.
• Inlining the helper function reduces function call overhead, which makes the code slightly faster.
• The overall time and space complexity remains O(n), where n is the length of args, but with lower constants contributing to improved performance.

Correctness verification

The new optimized code was tested for correctness. The results are listed below.

🔘 (none found) − ⚙️ Existing Unit Tests

✅ 20 Passed − 🌀 Generated Regression Tests

(click to show generated tests)

# imports
from typing import Any, Optional

import pytest  # used for our unit tests
from hogvm.python.stl.__init__ import concat
# function to test
from posthog.models import Team

# unit tests

def test_basic_concatenation():
    # Test concatenating a list of strings
    assert concat("test", ["hello", "world"], None, None, 10) == "helloworld"
    assert concat("test", ["foo", "bar", "baz"], None, None, 10) == "foobarbaz"

def test_handling_none_values():
    # Test handling None values
    assert concat("test", [None, "hello", None], None, None, 10) == "hello"
    assert concat("test", [None, None, None], None, None, 10) == ""

def test_handling_boolean_values():
    # Test handling boolean values
    assert concat("test", [True, False, True], None, None, 10) == "truefalsetrue"
    assert concat("test", [False, False, True], None, None, 10) == "falsetrue"

def test_mixed_data_types():
    # Test combining strings, numbers, and booleans
    assert concat("test", ["start", 123, True, 45.67, False, "end"], None, None, 10) == "start123true45.67falseend"
    assert concat("test", [1, "two", 3.0, True, None], None, None, 10) == "1two3.0true"

def test_empty_and_single_element_lists():
    # Test empty list
    assert concat("test", [], None, None, 10) == ""
    # Test single element list
    assert concat("test", ["only"], None, None, 10) == "only"
    assert concat("test", [None], None, None, 10) == ""

def test_special_characters():
    # Test list with special characters
    assert concat("test", ["hello", " ", "world", "!"], None, None, 10) == "hello world!"
    assert concat("test", ["foo", "\n", "bar"], None, None, 10) == "foo\nbar"

def test_empty_strings():
    # Test list with empty strings
    assert concat("test", ["", "hello", "", "world", ""], None, None, 10) == "helloworld"
    assert concat("test", ["", "", ""], None, None, 10) == ""

def test_large_scale():
    # Test large list of elements
    assert concat("test", ["a"] * 1000, None, None, 10) == "a" * 1000
    assert concat("test", list(range(1000)), None, None, 10) == "".join(map(str, range(1000)))

def test_performance_and_scalability():
    # Test very large list of mixed elements
    large_list = ["a", 1, True, None] * 10000
    expected_result = ("a1true" * 10000)
    assert concat("test", large_list, None, None, 10) == expected_result

def test_ignored_parameters():
    # Ensure ignored parameters do not affect the result
    assert concat("test", ["hello", "world"], Team(), ["output"], 10) == "helloworld"
    assert concat("test", ["foo", "bar"], None, ["log"], 20) == "foobar"

🔘 (none found) − ⏪ Replay Tests

[misrasaurabh1]

is faster but less readable