Assignment
Values
We’ve seen that Rye code can consist of literal values, for example:
33 ; integer
"Hello word" ; text
https://example.com ; URL
'word ; literal word
{ 1 2 3 } ; block of integers
{ "Hello" "Word" } ; block of texts
Set-words
These values can be assigned to words using set-words, i.e. words that have a colon on their right.
age: 33
message: "Hello World"
website: https://example.com
type: 'word
numbers: { 1 2 3 }
words: { "Hello" "World" }
If you’ve programmed in any language before, the concept is the same as with variables.
Using bound words
We haven’t looked at function calls yet, but the use of the print function below will be self-evident I hope.
print "Hello world!"
; prints: Hello world!
message: "Hello Mars!"
; assigns text "Hello Mars!" to word message
print message
; prints: Hello Mars!
Assigning expression results
Values that get assigned to words can also come from expressions.
Again we haven’t looked at op-words yet, but the effect of + is probably understandable.
meaning: 24 + 18
print meaning
; prints: 42
Inline use
Everything in Rye returns a value. Use of set-words also return the assigned value, so they could be used inline within an expression.
fruits: 100 + apples: 12 + 21
; we set:
; apples: 33
; fruits: 133
Left set-words
You will see why later, but Rye also has set-words that take a value from the left.
"Jim" :name
12 + 21 :apples + 100 :fruits
Mod-words
But set-word from above will only allow you to set the word once. If you use set-word on a word already defined in current context you will get an error. For cases, where you need change a value bound to a word, you must use mod-word syntax.
It’s a little harder to look at, but that is by design. The goal is that you modify values under words only when you explicitly need to.
age: 42
sleep 3 .seconds ; todo make .seconds compat.
; age: 43
; Would produce an Error
age:: 43
The same holds true for the left mod-words. ::age.