Environment Diagrams

The questions below are due on Sunday July 06, 2025; 10:00:00 PM.
 
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Link to relevant section of reading

Problem 0 - Translate Diagram to Code

In the white code box to the right of the 1 below, enter any valid Python program that, when executed, would lead to the diagram above.

Problem 1 - Function Definition

Create a diagram representing the result of executing the following code, consisting of a single function definition. Remember that a function object must contain the argument names, the function's body, and a pointer to the frame in which it was defined (its "enclosing frame").

def foo(n, k):
    n = n / (k + d)
    return n

×

1. Drag objects into the field to construct a diagram.

2. Use dots to create lines for variable bindings and pointers.

3. Don’t like a line? Redraw from the source dot to remove.

4. Don’t like an object? Move to trash.

5. Don't like arrow placement? Try moving objects around to redraw.

6. Add annotations if you'd like. They don't affect correctness.

×
Are you sure you want to reset the diagram back to the starter state?
ℹ️
🗑️

Problem 2 - Calling Functions

When calling a function, we follow several steps:

  1. Evaluate the function to be called, and its arguments (in order)
  2. Create a new frame for the function call, with the function's enclosing frame as its parent
  3. Bind the parameters of the function to the given arguments in this new frame
  4. Execute the body of the function in this new frame.

This process is demonstrated through the examples from the readings.

Note that in this interface, we specify each frame's parent with a line from the dot at the top of each frame to its parent. Frames can also have a return value. We will diagram the return value of the function using the return pointer at the bottom of the frame. If the return pointer isn't set, this corresponds to a function returning None.

For this problem, diagram the result of executing the following code. Include each of the frames generated by function calls. For this problem, there should be three total frames: the global frame (already provided), one generated by a call to foo and one generated by a call to bar.

def foo(n, k):
    n = n / (k + d)
    return n

d = 10
n = 2
z = foo(36, n)

×

1. Drag objects into the field to construct a diagram.

2. Use dots to create lines for variable bindings and pointers.

3. Don’t like a line? Redraw from the source dot to remove.

4. Don’t like an object? Move to trash.

5. Don't like arrow placement? Try moving objects around to redraw.

6. Add annotations if you'd like. They don't affect correctness.

×
Are you sure you want to reset the diagram back to the starter state?
ℹ️
🗑️

Next Exercise: Hip to Be Square
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