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3_10.txt
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3_10.txt
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1. Result of evaluating (define W1 (make-withdraw 100)):
+----------------------------------------------+
global | make-withdraw:+----------------+ |
env | | |
| W1:++ | |
+---------------------^----------------------^-+
| | | |
| E1: | | |
| +------------+------+ +-v-+---+ |
| |initial—amount: 100| | | +----+
| +------------^------+ +-+-+---+
| | |
| E2 | v
| +------------+------+ parameters: initial-amount
| |balance: 100 | body: ((lambda (balance)
| +------------^------+ (lambda (amount) ...)
| | initial-amount)
+-+-+---+ |
| | +--------+
+-+-+---+
|
|
v
parameters: amount
body: (lambda (amount)
(if (>= balance amount) ...)
2. Environment during invocation of (W1 50):
+------------------------------------------------+
global | make-withdraw: ... |
env | |
| W1:++ |
+---------------------+--------------------------+
| |
| E1: |
| +------------+------+
| |initial—amount: 100|
| +------------^------+
| E2 |
| +------------+------+
| |balance: 100 |
| +------------^----^-+
| | |
| | +-+--------+
+-v-+---+ | |amount: 50|
| | +--------+ +----------+
+-+-+---+
| calling (lambda (amount)
| (if (>= balance amount) ...)
v
parameters: amount
body: ...
3. Frames after evaluating (W1 50).
+------------------------------------------------+
global | make-withdraw: ... |
env | |
| W1:++ |
+---------------------^--------------------------+
| |
| E1: |
| +------------+------+
| |initial—amount: 100|
| +------------^------+
| |
| E2 |
| +------------+------+
| |balance: 50 |
| +------------^------+
| |
+-+-+---+ |
| | +--------+
+-+-+---+
|
|
v
parameters: amount
body: ...
4. Result of evaluating (define W2 (make-withdraw 100))
+------------------------------------------------+
global | make—withdraw: ... |
env | W2:+-------------------------+ |
| W1:—\ | |
+------+--------------+--------------------------+
| | |
| E1: | | E3:
| +------------+------+ | +-------------------+
| |initial—amount: 50 | | |initial—amount: 100|
| +------------^------+ | +------------^------+
| | | |
| E2 | | E4: |
| +------------+------+ | +------------+------+
| |balance: 50 | | |balance: 100 |
| +------------^------+ | +------------^------+
| | | |
| | | |
+-v-+---+ | +-v-+---+ |
| | +--------+ | | +--------+
+-+-+---+ +-+-+---+
| |
| +-------------------+
v v
parameters: amount
body: ...