Sequencing

& Effects

CSC 151 - Functional Problem Solving

Leah Perlmutter | Fall 2024

Agenda for Today

1. Announcements
2. Sequencing & Effects
3. Lab

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Announcements

Announcements

• Election stress is real!
• Make plenty of space for self care
• CS Extras: Decision Diagrams Theory and Applications
• Prof. Gianfranco Ciardo, Iowa State University
• Thurs 11/7
• 4:00 pm snacks in Noyce 3817
• 4:15 pm talk in Noyce 3821

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Announcements

• Quiz Friday on Dictionaries (Association Lists)
• remember that many dictionary manipulation operations require recursion
• the quiz might or might not require recursion

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• Heads up: It gets harder from here!
• Assessment revisions
• start with the earliest material
• start early

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Program State

• Self check
• to trace a let binding
• first we evaluate the expression for each binding
• then we substitute in each name for its value in the body of the let expression

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Terms

• purity
• A pure functional program is one that has no side effects
• referential transparency
• An expression is referentially transparent if it can be replaced by the value that it evaluates to without any change in meaning to our program.

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This lab is about working with non-pure programs that don't have referential transparency. We need to track state.

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Before we begin

• Suggested Ice Breaker: What have you been doing for self care recently?

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Lab time!

Lab Tips

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End of lab

• 5 minutes left -- make a plan to finish your lab exercises!
• Before submitting, make a comment in your lab code saying how far you got through the exercises
• check course website for assignments and due dates
• When you go, put note cards back in bin if you have not already

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