Outline:

1. Recap: evaluating Scheme
   • environment model of evaluation
   • define, let, if
2. Evaluating special form: lambda
   • closures
   • exercises
3. Wrap-up

After class

4. Explore the rest of the exercises from today.

What’s next

Upcoming events/assessments:

• Interpreter Parts 1+2 (linked list + talloc) cannot be resubmitted after tonight at 10pm
• Interpreter Part 3 (tokenizer) cannot be resubmitted after Friday at 10pm
• Quiz 5 will be this Friday and cover the following Quiz Learning Objectives:
  • Core:
    • PL 5: parse trees
    • PL 6: scoping
    • IP 4: parsing
  • Advanced:
    • IP 6: catching errors
  • Repeat:
    • FS 5: higher-order functions (CR)
    • IC 3: structs (CR)
    • IC 4: arrays (CR)
    • PL 7: side effects (AD)
    • FS 10: implementing higher-order functions (AD)
    • FS 12: writing Scheme (AD)
    • IC 8: writing C (AD)

What you should do now:

• Read the assigned readings (see below)
• Finish resubmitting Interpreter Parts 1–3 with more complete functionality, style fixes, etc.
• Finish Interpreter Part 4: Parser
• Start Interpreter Part 5: If/let/quote

Reading assignment (to be completed by the next class):

Lambda and closures (from today):

• Lambda in Python
• Lambda in Kotlin
• Lambda in Java
• Closures

For next time:

• nothing new, just study for Quiz 5 and (re-)read assignment writeups