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| title | TARGET DECK | FILE TAGS | tags | |
|---|---|---|---|---|
| Short-Circuit | Obsidian::STEM | logic |
|
Overview
The \textbf{cand} and \textbf{cor} operator allows short-circuiting evaluation in the case of undefined (U) values.
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Basic
What truth values do short-circuit evaluation operators act on?
Back: T, F, and U
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
What C operator corresponds to \textbf{cand}?
Back: &&
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
Tags: c17
END%%
%%ANKI
Basic
Why is \textbf{cand} named the way it is?
Back: It is short for conditional and.
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
How is p \textbf{ cand } q written as a conditional?
Back: \textbf{if } p \textbf{ then } q \textbf{ else } F
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
When can \textbf{cand} evaluate to a non-U value despite being given a U operand?
Back: F \textbf{ cand } U = F
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
What C operator corresponds to \textbf{cor}?
Back: ||
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
Tags: c17
END%%
%%ANKI
Basic
Why is \textbf{cor} named the way it is?
Back: It is short for conditional or.
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
How is p \textbf{ cor } q written as a conditional?
Back: \textbf{if } p \textbf{ then } T \textbf{ else } q
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
When can \textbf{cor} evaluate to a non-U value despite being given a U operand?
Back: T \textbf{ cor } U = T
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
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- Associative Laws
E1 \textbf{ cand } (E2 \textbf{ cand } E3) = (E1 \textbf{ cand } E2) \textbf{ cand } E3E1 \textbf{ cor } (E2 \textbf{ cor } E3) = (E1 \textbf{ cor } E2) \textbf{ cor } E3
%%ANKI Basic Which of the short-circuit logical operators do the commutative laws apply to? Back: Neither of them. Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
Which of the short-circuit logical operators do the associative laws apply to?
Back: \textbf{cand} and \textbf{cor}
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
- Distributive Laws
E1 \textbf{ cand } (E2 \textbf{ cor } E3) = (E1 \textbf{ cand } E2) \textbf{ cor } (E1 \textbf{ cand } E3)E1 \textbf{ cor } (E2 \textbf{ cand } E3) = (E1 \textbf{ cor } E2) \textbf{ cand } (E1 \textbf{ cor } E3)
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Basic
What is the distributive law of e.g. \textbf{cor} over \textbf{cand}?
Back: E1 \textbf{ cor } (E2 \textbf{ cand } E3) = (E1 \textbf{ cor } E2) \textbf{ cand } (E1 \textbf{ cor } E3)
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
- De Morgan's Laws
\neg (E1 \textbf{ cand } E2) = \neg E1 \textbf{ cor } \neg E2\neg (E1 \textbf{ cor } E2) = \neg E1 \textbf{ cand } \neg E2
%%ANKI
Basic
Which of the short-circuit logical operators do De Morgan's Laws apply to?
Back: \textbf{cand} and \textbf{cor}
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
%%ANKI
Basic
What is De Morgan's Law of e.g. \textbf{cor}?
Back: \neg (E1 \textbf{ cor } E2) = \neg E1 \textbf{ cand } \neg E2
Reference: Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.
END%%
Gries lists other "Laws" but they don't seem as important to note here. What's worth noting is that the other equiv-trans#Equivalence Schemas still apply if we can limit operands to just T and F.
References
- Gries, David. The Science of Programming. Texts and Monographs in Computer Science. New York: Springer-Verlag, 1981.