{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lec10 - CMPSC 461 Programming Language Concepts Lecture 10...

Info icon This preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
CMPSC 461: Programming Language Concepts Lecture 10 Instructor: Prof. Swarat Chaudhuri
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Data abstraction Procedure / list empty-env extend-env apply-env Implementation Interface Client Client Environment +
Image of page 2
Recursive data types Bintree ::= Number | Symbol Bintree Bintree | Symbol Bintree Environment: - contains? - traverse-postorder - traverse-preorder -
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Defining interfaces: follow the grammar Data type defined recursively using grammar What we need A way to construct an instance of the type according to a rule. (Constructor) Given a data item, answer: “was this item constructed using rule X?” (Predicate) If it was, a way to break it down into sub-items following rule X. (Extractor) Why? Because clients need these operations to follow the grammar. Each rule gives a variant of the data type.
Image of page 4
Recursive data types Bintree ::= leaf: Number | int-2: Symbol Bintree Bintree | int-1: Symbol Bintree leaf int-2 int-1
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
define-datatype A mechanism in our Scheme dialect to define recursive data types.
Image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern