Glossary: arguments, arrays and syntax trees — DedSec Project

Argument

How this concept behaves

Concrete value supplied at a function call, distinct from a parameter name in the function definition. Positional and keyword arguments can affect how an API evolves.

Work through a small example

def join(left,right): return left+'-'+right
assert join('a','b')=='a-b'
assert join(right='b',left='a')=='a-b'

Investigate the behavior

Exchange positional argument order and observe the result; then add a keyword-only optional separator.

Explain a boundary case

For Argument, test a second input that changes the outcome and record the expected behavior before execution. Explain which requirement fails and why the baseline example does not cover it.

Array

How this concept behaves

Indexed collection whose layout, indexing rules and element types depend on language. A fixed-size C array and a dynamic Python list are not interchangeable concepts.

Work through a small example

items=[8,13,21]
assert items[0]==8
assert items[-1]==21

Investigate the behavior

Compute memory and mutation implications of an integer array versus a heterogeneous list; test an out-of-range index.

Explain a boundary case

For Array, test a second input that changes the outcome and record the expected behavior before execution. Explain which requirement fails and why the baseline example does not cover it.

AST

How this concept behaves

A tree representing parsed program structure rather than source whitespace or comments. Tools traverse AST nodes to analyze expressions, transform code or build diagnostics.

Work through a small example

import ast
node=ast.parse('x=2+3')
assert isinstance(node.body[0], ast.Assign)
assert isinstance(node.body[0].value, ast.BinOp)

Investigate the behavior

Compare AST dumps of x=2+3 with x = 2 + 3 and explain why formatting does not change the essential tree.

Explain a boundary case

For Abstract syntax tree, test a second input that changes the outcome and record the expected behavior before execution. Explain which requirement fails and why the baseline example does not cover it.

Asynchronous

How this concept behaves

Control flow where an operation can suspend while awaiting IO and other tasks may advance. Async syntax alone does not speed up CPU-heavy calculations or guarantee parallel threads.

Work through a small example

import asyncio
async def task():
    await asyncio.sleep(0)
    return 7
assert asyncio.run(task())==7

Investigate the behavior

Run two asynchronous sleep tasks concurrently and compare elapsed time with sequential waits; avoid real external services.

Explain a boundary case

For Asynchronous, test a second input that changes the outcome and record the expected behavior before execution. Explain which requirement fails and why the baseline example does not cover it.

Atomicity

How this concept behaves

A group of actions appears all-or-nothing at a specified boundary. SQLite transactions offer atomic commit/rollback; a pair of Python assignments is not automatically atomic across services.

Work through a small example

BEGIN;
INSERT INTO tasks(title) VALUES ('draft');
ROLLBACK;
-- No inserted row should remain.

Investigate the behavior

Reproduce a failed transaction in a disposable database, then verify both its successful and rejected writes are handled consistently.

Explain a boundary case

For Atomicity, test a second input that changes the outcome and record the expected behavior before execution. Explain which requirement fails and why the baseline example does not cover it.