Exercises for Week 02

Exercise 0

1. At the top right and at the bottom right of the present page, there is a clickable word, “index”, to access the index of the current version of the lecture notes. Click on it and then peruse the index, making sure that its entries make sense to you (otherwise, click on them to check them out).
2. In the light of your homework from Week 01, read again the vision and the mission of Yale-NUS College.
3. In reference to the section about Using a grammar to generate grammatically correct sentences, do check out Strachey’s generator of love letters and the generator of mathematical proofs. (Make sure to reload these web pages a few times.)

Mandatory exercises

• Exercise 0: perusing the index, reflecting on the vision and the mission of Yale-NUS College, and checking out the generators of love letters and mathematical proofs
• Exercise 1: reflecting on programs and data
• Exercise 2: specializing an interpreter with respect to a program
• Exercise 3: the four causes of a partial evaluator
• Exercise 6: specializing the specializer with respect to an interpreter
• Exercise 8: playing with grammars and languages
• Exercise 11: constructing a few abstract-syntax trees
• Exercise 12: writing a few regular expressions
• Exercise 13: constructing a few proof trees
• Exercise 14: finding the root of proof trees
• Exercise 16: the four causes of compilation in Computer Science
• Exercise 22: (re)visiting the section about Compile time, run time, and efficiency in Week 01

Recommended additional exercises

• Exercise 7: specializing the specializer with respect to the specializer

Practicalities

• Like last week, feel free to draw your solutions with a pencil, take low-resolution snapshots of them, and include these snapshots in your report.
• Like last week, please upload a separate file “week-02.txt” containing your names, student numbers, and email addresses. But this time, create this file using Emacs.
• Unlike last week, submit your homework on Canvas as a group, not as an individual, so that all the members of the group get a recorded grade on Canvas, not only the individual who submitted.
• For Week 01, in order for each other member of each group to get a recorded grade on Canvas, sigh, please submit individually a token file so that I can assign it the grade of your group.

This is a mechanism, not a solution.

—Mao Zedong

Exercise 15

Write down as many as you like of the four causes of interpretation in Computer Science, in the order of your choosing:

• material cause
• efficient cause
• formal cause
• final cause

How does your solution compare with the four causes of an interpreter, in Exercise 3 of Week 01?

Exercise 16

Write down as many as you like of the four causes of compilation in Computer Science, in the order of your choosing:

• material cause
• efficient cause
• formal cause
• final cause

How does your solution compare with the four causes of a compiler, in Exercise 4 of Week 01?

Version

Created [21 Jan 2021]