Inquirer

__init__

__init__(self, oracles: Sequence[PriceOracle]) -> None

Hold oracles; query order is construction order.

Parameters

usd_prices

usd_prices(self, caip19s: Sequence[str]) -> dict[str, Money]

Merged first-wins USD prices for caip19s.

Validates every id up front (CaipParseError before any oracle call), deduplicates preserving first occurrence, then walks the oracles in order asking each only for the still-unpriced ids and stopping early once everything is priced. Unpriced ids are absent from the result, never an error.

Parameters

Raises

CaipParseError

usd_prices_at

usd_prices_at(self, caip19s: Sequence[str], at_ms: int) -> dict[str, Money]

Merged first-wins USD prices for caip19s as of at_ms.

The same walk as usd_prices: every id is parsed up front (CaipParseError before any oracle call), the input is deduplicated preserving first occurrence, oracles are queried in construction order, each subsequent one is asked only for the still-unpriced ids, the walk stops once everything is priced, and unpriced ids are absent from the result.

Two rules apply here and not there. An oracle with no callable usd_prices_at is SKIPPED and never called, so a 0.1.x oracle cannot answer a 2021 question with today's number. An oracle whose unreachable_instant(at_ms) returns a string is SKIPPED WITHOUT being called, so an instant it cannot reach costs zero I/O. absences_at reports both kinds of skip.

Raises ValidationError when at_ms is not an integer (bool included) and CaipParseError for a malformed id.

Parameters

Raises

CaipParseError, ValidationError

absences_at

absences_at(self, at_ms: int) -> tuple[str, ...]

One stated reason per oracle that cannot answer at at_ms.

PURE: no I/O, and neither usd_prices nor usd_prices_at is called on any oracle. The strings come back in construction order, and an oracle that can answer contributes nothing.

An oracle with a callable unreachable_instant contributes whatever string it returns for at_ms. Otherwise an oracle with no callable usd_prices_at contributes the generated sentence f"{type(oracle).__name__} has no usd_prices_at; it answers the current instant only". An oracle the walk WOULD ask contributes its own absences when it is a chain in its own right (_composed_absences), and nothing when it is a leaf.

Raises ValidationError when at_ms is not an integer.

Parameters

Raises

ValidationError