Flow control

Typescript Genie offers two method to append to builders conditionally. For conditions, each builder contains $if and for mapping arrays builders contains $reduce.

.$if(condition, isTruthy)

Method .$if calls and returns the isTruthy function if the condition is truthy. This is useful for example when rendering some interface property if some data are available.

With $if

const withAge = () => Math.random() > 0.5;

const interfac = tsg.statement.interface("Person")
  .prop("firstname", "string")
  .$if(withAge(), i => i.prop("age", "number"));

Without $if

const withAge = () => Math.random() > 0.5;

let interfac = tsg.statement.interface("Person")
  .prop("firstname", "string");

if(withAge()) {
  interfac = i.prop("age", "number");
}

.$reduce(iterable, accumulator)

Method .$reduce chains accumulator calls for each item in the iterable (e.g. array). This is useful when dealing

With $reduce

const properties = {
  firstname: "string",
  age: "number"
} as const;

let interfac = tsg.statement.interface("Person")
  .$reduce(Object.entries(properties), (i, [key, value]) =>
    i.prop(key, value)
  );

Without $reduce

const properties = {
  firstname: "string",
  age: "number"
} as const;

let interfac = tsg.statement.interface("Person");

for (const [key, value] of Object.entries(properties)) {
  interfac = interfac.prop(key, value);
}