#04. Scalar types

Let's start reading the schema in smaller pieces.

#Start the demo server

telepact demo-server --port 8000

#The scalar type expressions

Type expression	Meaning
`boolean`	`true` or `false`
`integer`	whole number
`number`	JSON number
`string`	JSON string
`bytes`	binary data

Nullability is written with a ? suffix, like number? or string?.

#Where they show up in the demo schema

{
  "fn.add": {"x": "number", "y": "number"},
  "fn.getPaperTape": {"limit!": "integer"},
  "fn.login": {"username": "string"},
  "struct.Evaluation": {
    "result": "number?",
    "timestamp": "integer",
    "successful": "boolean"
  },
  "fn.export": {},
  "->": [{"Ok_": {"blob": "bytes"}}]
}

#Real examples

#`number`

curl -s localhost:8000/api -d '[{}, {"fn.add": {"x": 1.5, "y": 2}}]'

[{}, {"Ok_": {"result": 3.5}}]

#`integer`, `boolean`, and nullable `number?`

Let's create one evaluation and then read it back:

curl -s localhost:8000/api -d '[{}, {"fn.evaluate": {"expression": {"Constant": {"value": 7}}}}]'
curl -s localhost:8000/api -d '[{}, {"fn.getPaperTape": {"limit!": 1}}]'

Example response:

[
  {},
  {
    "Ok_": {
      "tape": [
        {
          "expression": {"Constant": {"value": 7}},
          "result": 7,
          "timestamp": 1744221600,
          "successful": true
        }
      ]
    }
  }
]

#`bytes`

curl -s localhost:8000/api -d '[{}, {"fn.export": {}}]'

Example response:

[
  {
    "@base64_": {
      "Ok_": {
        "blob": true
      }
    }
  },
  {
    "Ok_": {
      "blob": "gql2YXJpYWJsZXO..."
    }
  }
]

The schema says bytes, but JSON has no raw bytes type, so Telepact coerces the wire value to Base64.

Next: 05. Collection types