A qubit index that depends on a measurement cannot be resolved, because qubits are assigned at compile time.
Recursion that is not a tail call is only expanded when its depth is known at compile time, up to 10,000 calls deep, or 32 in the browser.
The state vector holds up to 30 qubits, or 20 in the browser. Above that a circuit without structure to exploit runs as a matrix product state, which is exact only while its entanglement fits the bond cap and otherwise reports the weight it dropped.
OpenQASM 3 input reads classical values that are set once. Values that change, bool, break and subroutines are refused.
--epsilon reaches a precision of about 1e-10 for each rotation, and some angles take several seconds there, since the candidates are enumerated one coordinate at a time rather than by Ross and Selinger’s grid operators.
Circuit cutting pays off only while few gates join the pieces, because the work grows with the square of the product of the terms of every cut, and cut sampling measures at most 20 qubits.
Resource estimates follow one layout, a fast block with 15-to-1 factories and one error rate for every operation, so they are a first estimate rather than a compiled fault tolerant schedule.
OpenQASM 3 output writes branches as if and else, loops as a while over blocks, classical values as typed variables and recorded values as output variables. A floating point remainder, a pointer cast or a value recorded inside a loop is refused rather than approximated, and --emit qir keeps them.
QIR output decomposes a controlled gate that has no QIR function of its own, and refuses one with three or more controls.
qirc submit talks to IonQ only, and has been tested against a local imitation of its API rather than a live account.
A single cross resonance pulse per CNOT, without echo or rotary tones, is a starting point to calibrate against a device rather than a finished gate.