The Environmental model of evaluation, applying simple procedures.

1. MCN 7105: Structure and Interpretation of Computer
Programs
Group I (CS)
Applying Simple Procedures
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2. Overview
1 Applying Simple Procedures
Introduction
Procedure Definition
Procedure Evaluation
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3. Applying Simple Procedures Introduction
Applying Simple Procedures
An environment consists of a sequence of frames.
A frame is a table of bindings, a pairing of a name and a value.
A frame might be shared by multiple environments.
A procedure object consists of some code, together with a pointer
to the enclosing environment.
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4. Applying Simple Procedures Procedure Definition
Procedure Definition
average
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5. Applying Simple Procedures Procedure Evaluation
Procedure Evaluation
Steps
To apply a compound procedure P to arguments:
Create a new frame A
Make A into an environment E
In A, bind the parameters of P to the argument values
Evaluate the body of P with E as the current environment
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6. Applying Simple Procedures Procedure Evaluation
Procedure Evaluation
average
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7. Applying Simple Procedures Procedure Evaluation
Procedure Definition
hypotenuse
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8. Applying Simple Procedures Procedure Evaluation
Procedure Evaluation
hypotenuse
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9. Applying Simple Procedures Conclusion
Questions?
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