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Quick reference

Screw long documentation, I’ll learn by example

Quick reference

Syntax

a: b property a of type b

a: b someMod[modType: value] property a of type b, and also we know that a has setting someMod, and that setting’smodType is set to value. Modifiers can:

  • specify filtering parameters and variable domains

    a:int always[a> 5] or just a:int [a>5] defines possible value range

    a:int typically[a<10] or [a ~< 10] define reasonable value range

  • add semantic info, specify data format or middlewares. comp1.inName -- format[json] ---> comp2.outName

hostname~dev = dev.mytool.com tilde (~) is used to define deploy-specific (or machine/user-specific) values.

hostname ~username:user ~nodename:node

MyComponent^V1 MyComponent of version 1.

MyComponent!varX MyComponent variant (design draft) varX:

MyComponent!varX :component(
    -completely_removed_stuff: str
    
    -old_field: int
    +new_replacing_field: int
    
    kept_stuff: float
    
    +completely_new: str
)

_source: src/app/server.py#L30..50 defines binding to source files

_import: URI/

  • [public] share with everyone
  • [private] do not share outside of dev group
  • [external] described here, but we do not control that

Objects

defines business data structure

MyDataSchema: schema [size ~ 30 bytes] [version=V1] (
    a: int [id]
    b: float [b>0]
    dt: str
    d: enum[MyEnum: value1, value2, value3]
)

Cluster is a set of nodes (think of autoscaling group).

Node is a machine, virtual or dedicated.

Storages store data. Stored schema is usually different than business logic’s schema.

Apps are running services or scheduled periodically firing pipelines. Apps are made of components, which define pieces of logic. Usually we do not care what happens inside them

Layers can be skipped.

  • --> is “read from”
  • < is “write to”
  • | is “triggered from outside”; | something | states that something happens outside of the app / component.

  • |> apiName: intype > outtype >| - api definition

    stream is a sequence of objects which we dispatch one by one

batch is a

MyApp: app (
    comp1: component (
        |> config: sigle[config]
        > inName: stream[datatype]
        < outName: batch[datatype]
        |> apiName: stream[indatatype] > stream[outdatatype] >|
        <| callName: stream[outDataType] < stream[inDataType] |<
    )
)

Storages store data. Not all data inside belongs to business schema; some fields are technical.

MyDB: storage (
    mytable: schema (
        id: MyDataSchema.id
        
    )
)