Jasp

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Everyone[citation needed] knows that object-oriented programming is superior to the list-oriented programming of the Lisp family, and that JSON is superior to S-Expressions. Introducing Jasp, a language that lets you program in a Scheme-like dialect using nothing but JSON!

Syntax

Symbol definition
{
    "operator": "define",
    "name": <string>,
    "value": <expr>
}
Mutation
{
    "operator": "set!",
    "name": <string>,
    "value": <expr>
}
Reference

If "x" is defined in the current environment, "$x" returns the value, whereas "x" is just a string. The dollar sign is not necessary if the referenced symbol is in the operator position.

Branching
{
    "operator:" "if",
    "predicate": <expr> ,
    "then": <expr>,
    "else": <expr>
}
Sequencing Jasp interprets naked arrays as sequences of instructions, like (begin) in Scheme.
[
    { "operator": "set!", "name": "x", "value": 2 },
    { "operator": "display", "arguments" [ "$x" ] },
    "$x" // returns the value of "x" from the sequence
]
Quotation
{
    "operator": "quote",
    "value": <expr>
}
Abstraction
{
    "operator": "lambda",
    "arguments": [ "string", "string", ... ]
    "body": <expr> // (can be an array, interpreted as a sequence)
}
Function application
{
    "operator": "foo",
    "arguments": [ 1, 2, 3 ]
}
Reflection
{
    "operator": "eval",
    "code": <quoted-expr>
}

Example

Here is a simple program to calculate the factorial of 100 and display it:

 [
   {
       "operator": "define",
       "name": "fact",
       "value": {
           "operator": "lambda",
           "arguments": [ "n" ],
           "body": {
               "operator": "if",
               "predicate": { "operator": "=", "arguments": [ "$n", 0 ] },
               "then": 1,
               "else": {
                   "operator": "*",
                   "arguments": [
                       "$n",
                       {
                           "operator": "fact",
                           "arguments": [
                               {
                                   "operator": "-",
                                   "arguments": [ "$n", 1 ]
                               }
                           ]
                       }
                   ]
               }
           }
       }
   },
 
   {
       "operator": "display",
       "arguments": [
           {
               "operator": "fact",
               "arguments": [ 100 ]
           }
       ]
   }
 ]

External resources