Referenced from lesson Method Chaining

You have the following functions defined below (read them carefully!):

fun is-female(r): r["sex"] == "female"  end
fun kilograms(r): r["pounds"] / 2.2     end
fun is-heavy(r):  r["kilos"] > 25       end

The table t below represents four animals from the shelter:

name sex age fixed pounds

"Toggle"

"female"

3

true

48

"Fritz"

"male"

4

true

92

"Nori"

"female"

6

true

35.3

"Maple"

"female"

3

true

51.6

Match each Pyret expression (left) to the description of what it does (right). Note: one description might match multiple expressions!

t.order-by("kilos", true)

1

A

Produces a table containing Toggle, Nori and Maple, with an extra column showing their weight in kilograms

 
t.filter(is-female)
  .build-column("kilos", kilograms)

2

B

Produces a table containing Maple, Nori and Toggle (in that order)

 
t.build-column("kilos", kilograms)
  .filter(is-heavy)

3

C

Produces a table containing only Fritz, with a single extra column called kilos

 
t.filter(is-heavy)
  .build-column("kilos", kilograms)

4

D

Won’t run: will produce an error

 
t.build-column("kilos", kilograms)
  .filter(is-heavy)
  .order-by("sex", true)

5

E

Produces a table containing only Fritz, with two extra columns

 
t.build-column("female", is-female)
  .build-column("kilos", kilograms)
  .filter(is-heavy)

6

F

Produces a table containing Maple and Fritz

These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, and 1738598). CCbadge Bootstrap:Data Science by Emmanuel Schanzer, Nancy Pfenning, Emma Youndtsmith, Jennifer Poole, Shriram Krishnamurthi, Joe Politz, Ben Lerner, Flannery Denny, and Dorai Sitaram with help from Eric Allatta and Joy Straub is licensed under a Creative Commons 4.0 Unported License. Based on a work at www.BootstrapWorld.org. Permissions beyond the scope of this license may be available by contacting schanzer@BootstrapWorld.org.