I.7 Semester I Review 7

This page contains additional review exercises.

Basic Spanish

We will write a function to conjugate regular verbs “-ar” and “-er” verbs according to the following chart. Use the ending letters to decide how to categorize a given verb. We will only consider the present and past tense (preterit) of the verbs.

Verb Subject Past? Result is base + Example (“andar”/“correr”)
-ar yo false -o ando
-ar yo true -é andé
-ar tu false -as andas
-ar tu true -aste andaste
-er yo false -o corro
-er yo true -í corrí
-er tu false -es corres
-er tu true -iste corriste

Signature:

conjugar: string(verb-infinitive) 
          string(person) 
          boolean(past-tense?) 
          -> string

Example:

(check-expect (conjugar "correr" "tu" true) 
              "corriste")

Note: ignore accents.

Too much? Try the simplified, present tense only function:

Verb Subject Result is base + Example (“andar”/“correr”)
-ar yo -o ando
-ar tu -as andas
-er yo -o corro
-er tu -es corres

Placed objects

An image-posn is an image together with a posn.

  1. draw-it: ip image(background) -> image
  2. teleport: ip(shape1) ip(shape2) -> ip(new-shape1): Produce a new ip whose image is the same as shape1 but whose position is the same as shape2. This has the effect of moving shape1 on top of shape2.
  3. Make an animation that remembers two images with their positions.
  4. When you hit the “t” key, the first image teleports to the second image.
  5. When you click the mouse, the first image jumps to the mouse’s position.
  6. The second image slowly moves left and up from its original position, maybe 6 pixels every 0.5 seconds.