Referenced from lesson Method Chaining
You have the following functions defined below (read them carefully!):
fun is-fixed(r): r["fixed"] end fun is-young(r): r["age"] < 4 end fun nametag(r): text(r["name"], 20, "red") end
The table t
below represents four animals from the shelter:
name | sex | age | fixed | pounds |
---|---|---|---|---|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Match each Pyret expression (left) to the description of what it does (right).
t.order-by("age", true) |
1 |
A |
Produces a table containing only Toggle and Maple |
|
t.filter(is-fixed) |
2 |
B |
Produces a table of only young, fixed animals |
|
t.build-column("sticker", nametag) |
3 |
C |
Produces a table, sorted youngest-to-oldest |
|
t.filter(is-young) |
4 |
D |
Produces a table with an extra column, named "sticker" |
|
t.filter(is-young) .filter(is-fixed) |
5 |
E |
Produces a table containing Maple and Toggle, in that order |
|
t.filter(is-young) .order-by("pounds", false) |
6 |
F |
Produces a table containing the same four animals |
|
t.build-column("label", nametag) .order-by("age", true) |
7 |
G |
Won’t run: will produce an error |
|
t.order-by("agee", false) |
8 |
H |
Produces a table with an extra "label" column, sorted youngest-to-oldest |
These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, and 1738598). 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.