Probably depends on whom you are asking. For me the essence is (1) having functions or procedures as the basic building blocks, not classes. (2) Having all the utility and higher order functions you need to deal with the functions and procedures first idea. (3) Having a very powerful syntax, that allows great semantic editing and is never ambiguous. Oh and can actually be extended in useful ways, without having to wait for a committee to decide upon "the one syntax to rule them all".
> can actually be extended in useful ways
I just made a library with [query syntax](https://codeberg.org/veqq/declarative-dsls) over various data structures a la sql:
(import declarative-dsls/dataframes :as df)
(def people (df/dataframe :name :age :job))
(df/dataframe? people)
(df/insert! {:name "Bob" :age 30 :job "Developer"} :into people)
(df/insert! {:name "Alice" :age 27 :job "Sales"} :into people)
(df/update! :set {:job "Engineer"}
:where |(= ($ :job) "Developer")
:from people)
(df/save-csv people "people.csv" :sep "\\t")
(def people2 (df/load-csv "people.csv" :sep "\\t"))
(-> people2
df/dataframe->rows
df/rows->dataframe
df/print-as-table)
job age name
-------- --- -----
Engineer 30 Bob
Sales 27 Alice
(df/v + [1 2 3] 1 [1 2 3] 1) # returns: [4 6 8]
(df/v + 1 {:column [1 2 3] :key [1 2 3]}) # returns: {:column @[2 3 4] :key @[2 3 4]}
(df/v * [1 2 3] [[1 1 1]
[1 2 2]
[1 2 3]]) # returns: @[@[1 1 1] @[2 4 4] @[3 6 9]]
(jnj/j "3 4 $ i. 10") # returns: ((0 1 2 3) (4 5 6 7) (8 9 0 1))
(jnj/j "$" [3 4] (range 10)) # returns: ((0 1 2 3) (4 5 6 7) (8 9 0 1))
From my response, bigger than the article: https://lobste.rs/s/y0euno/why_janet_2023#c_lspe6n
these little dsl's convey so much