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Version: 11.x

Type Alias: CairoTypeStrategy

CairoTypeStrategy = object

Defined in: src/utils/calldata/parser/cairoTypeStrategy.type.ts:38

How to build a Cairo type from an abi type, and how to read one back.

This is the shape the composite classes drive : unlike ParsingStrategy, whose entries go straight from a value to its felts, a constructor here returns a CairoType instance. That is what lets a composite hold its elements as a tree and serialize the whole of it at once, rather than each level having to flatten what it contains.

Every constructor receives the strategy back, because building a composite means building its children : an array of tuples of u8 has to reach this map three times.

Example​

const strategy: CairoTypeStrategy = {
  constructors: {
    [CairoUint8.abiSelector]: (input) => new CairoUint8(input),
  },
  response: {
    [CairoUint8.abiSelector]: (instance) => (instance as CairoUint8).toBigInt(),
  },
  dynamicSelectors: {},
};
const felts = strategy.constructors['core::integer::u8'](44, strategy).toApiRequest();
// felts = ["44"]

Properties​

constructors​

constructors: Record<AbiEntryType, (input, strategy, type?, variant?) => CairoType>

Defined in: src/utils/calldata/parser/cairoTypeStrategy.type.ts:47

Build a Cairo type, from raw data on the way out or from response felts on the way in.

The two directions share one entry because they build the same thing : input is whatever a caller passed for a request, and the iterator positioned on this value for a response. type and variant are given only where the abi key is not enough to know what to build — a dynamic selector matches a family of types, and an enum has to be told which branch it holds.

response​

response: Record<AbiEntryType, (instance, strategy) => any>

Defined in: src/utils/calldata/parser/cairoTypeStrategy.type.ts:63

Turn a built Cairo type back into the plain JS value a caller reads.

The strategy comes along for the same reason as above : decomposing a composite means decomposing its elements.

dynamicSelectors​

dynamicSelectors: Record<string, (type) => boolean>

Defined in: src/utils/calldata/parser/cairoTypeStrategy.type.ts:76

Recognize the types whose abi string is not a fixed key.

An array, a tuple, a fixed array, an Option or a NonZero write their element type into their own name, so there is no one string to key them by. Each entry here is a predicate on the abi type, and its key names the constructor to use — which is why a composite class carries a dynamicSelector telling which one built it.