The simplicity of JSON-FP expressions allows programmers to focus on functional blocks instead of splitting hairs on syntax of programming structure. That simplicity also makes metaprogramming feasible.

1. Programming Can Be Like Circuits
Drawing
A JSON-FP Perspective
By Ben Lue

2. JSON-FP
Expression
input output
Everything starts from …

3. Eventually, it could become
something like this:

4. Quite amazing, isn’t it?
Now we’ll introduce 3 basic data flow
constructors in JSON-FP:
chaining, if and bucket

5. JSON-FP
Expression
i JSON-FP
Expression
o/i JSON-FP
Expression
o/i o
Chaining

6. JSON-FP
Expression
i JSON-FP
Expression
o/i JSON-FP
Expression
o/i o
Chaining
Example
{“->”: [{multiply: 10}, {add: 5}, {divide: 10}]}
f(x) = ((x * 10) + 5) / 10

7. JSON-FP
Expression
i JSON-FP
Expression
o/i JSON-FP
Expression
o/i o
Chained expressions can be treated like an
single expression
“Fatter” JSON-FP
Expression
input output

8. Example
var add_5 =
{“->”: [{multiply: 10}, {add: 5}, {divide: 10}]};
var rounding =
{“->”:
[
add_5,
{floor: null}
]
};

9. Summary
 You can pipe (chain) JSON-FP expressions
to achieve the needed functionalities
(higher-order function).
 For readability and reuse purposes, you
can assign chained (or any compounded)
expressions to a variable.

10. JSON-FP
Expression
true
JSON-FP
Expression
If
JSON-FP
Expression
false

11. The syntax
{
if:
[
{predicate},
{expression_for_true},
{expression_for_false}
]
}

12. JSON-FP
Expression
Bucket
JSON-FP
Predicate
…
JSON-FP
Expression
JSON-FP
Predicate
JSON-FP
Expression
JSON-FP
Predicate
+
Ex: 1, 2, 3, 4, 5, …
1, 4, …
2, 5, …
3, 6, …

13. Bucket
 Input elements are evaluated against the
bucket predicates (which are JSON-FP
expressions) sequentially.
 If any predicate turns true, the element
belongs to that bucket and no further
checking will be done for that element.

14. Now can you visualize a JSON-FP
program as something like this:

15. Each JSON-FP expression takes exact
one input and produces exact one
output.

16. That makes it easy to connect
expressions.

17. Actually makes it easy to do
metaprogramming.
You don’t have to worry about syntax
or programming structure. You only
need to choose the right functional
block.

18. Want to play?
Check out the JSON-FP playground
http://playground.jsonfp.org

19. Fork me on Github
https://github.com/benlue/jsonfp