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, these would be the constants. The default assignment in Rye is to a constant.

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

Variables and mod-words

All of the above assigns (binds) a value to a word and makes that word a constant in the current context, meaning, we can’t later change it. This makes code more predictable.

Word can also become a variable in it’s context by using a function var and a lit-words (literary word). Such words can be modified using the modifying functions (ending with a !) or a mod-word.

; 5 minutes to midnight

var 'age 42

sleep ( 5 * 60 ) .seconds

; age: 43                              ; Would produce an Error

age:: 43

sleep 365 .days                        ; you would wait a while :)

change! 44 'age                        ; returns true if changed

Mod words are a little harder to look at, but that is by design. The goal is that you modify values under words only when you really need to.

The same holds true for the left mod-words. ::age.