Chain returns a new promise to compute function f on the result of promise p.

FromError creates a promise that simply returns the provided error when computed.

FromFunc creates a promise to call function f, where f returns any single value and has no facility to indicate an error.

FromFuncCtx creates a promise to call function f, where f accepts a context and returns any single value and has no facility to indicate an error, other than a context error.

FromOkFunc creates a promise to call function f, where f returns a (value, ok) tuple.

FromOkFuncCtx creates a promise to call function f, where f accepts a context and returns a (value, ok) tuple.

FromResultFunc creates a promise to call function f, where f returns a (result, error) tuple.

FromResultFuncCtx creates a promise to call function f, where f accepts a context and returns a (result, error) tuple.

FromValue creates a promise that simply returns the provided argument and a nil error when computed.

FromValueErr creates a promise that simply returns the provided argument or, if the provided error was non-nil, the provided error when computed.

WrapResultFunc wraps an existing function "f() => (X, error)" so that it becomes "f() => P[X]", a function that returns a promise.

WrapResultFunc1 wraps an existing function "f(A) => (X, error)" so that it becomes "f(A) => P[X]", a function that returns a promise.

WrapResultFunc2 wraps an existing function "f(A, B) => (X, error)" so that it becomes "f(A, B) => P[X]", a function that returns a promise.

WrapResultFunc3 wraps an existing function "f(A, B, C) => (X, error)" so that it becomes "f(A, B, C) => P[X]", a function that returns a promise.

WrapResultFunc4 wraps an existing function "f(A, B, C, D) => (X, error)" so that it becomes "f(A, B, C, D) => P[X]", a function that returns a promise.

P represents a promise to calculate and return some value when Compute or ComputeCtx is called.