Jasp

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

• Jasp implementation