Loops and Strings

Yesterday I left you with a program that really needed to "YS up"!

$ ys -e '
url =:
  "https://github.com/dominictarr/random-name/raw/master/first-names.json"

people =: url.curl().json/load().shuffle().take(3)
shoes =: read("shoes.yaml").yaml/load()

say: str(people.0, " wears size ", shoes.0.size, " ", join([shoes.0.name, "s"]))
say: str(people.1, " wears size ", shoes.1.size, " ", join([shoes.1.name, "s"]))
say: str(people.2, " wears size ", shoes.2.size, " ", join([shoes.2.name, "s"]))
'

Let's make this awesome!

YS Interpolation

Great interpolation is something I want in every language I program in. I don't always get it, but if I'm going to invent a new language, it's a must.

Interpolation is the ability to expand variables or expressions into a string, in place.

Here's a quick example of both in YS:

# File 'add'
!YS-v0
a b =: ARGS
say: "$a + $b = $(a + b)"

When we run it like this:

$ ys add 16 26
16 + 26 = 42

That's so simple. Both to write and for others to understand.

YS allows interpolation in double quoted strings and also literal strings (the | syntax) when the string is in "code mode". Just use $var or $(expr) to evaluate and expand them in place.

Let's use interpolation in our shoes program.

$ ys -e '
url =:
  "https://github.com/dominictarr/random-name/raw/master/first-names.json"

people =: url.curl().json/load().shuffle().take(3)
shoes =: read("shoes.yaml").yaml/load()

say: "$(people.0) wears size $(shoes.0.size) $(shoes.0.name)s"
say: "$(people.1) wears size $(shoes.1.size) $(shoes.1.name)s"
say: "$(people.2) wears size $(shoes.2.size) $(shoes.2.name)s"
'
Rebecca wears size 10 sneakers
Dian wears size 10 boots
Iolande wears size 8 sandals

Better!

Let's make it better still!

Loops

We could make this better if only YS had loops!

Pffft. We got your looping constructs right here! Several of them!

Let's use the each looping function for this.

$ ys -e '
url =:
  "https://github.com/dominictarr/random-name/raw/master/first-names.json"

people =: url.curl().json/load().shuffle().take(3)
shoes =: read("shoes.yaml").yaml/load()

each i range(people.count()):  # (0, 1, 2)
  person =: people.$i
  shoe =: shoes.$i
  say: "$person wears size $(shoe.size) $(shoe.name)s"
'
Myrtle wears size 10 sneakers
Phillis wears size 10 boots
Evonne wears size 8 sandals

I like it!

Take your shoes off!

By this time I bet you're getting tired of seeing programs about shoes.

Me too. Tomorrow will be different. Promise.

It's Summertime, let's go barefoot!

Comments