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slot_float ​

Summary. Interpret a slotted STI_AMOUNT as an XFL floating-point value.

Signature.

c
int64_t slot_float(uint32_t slot_no);

Parameters.

NameTypeDescription
slot_nouint32_tSlot holding an amount.

Return value. Returns the amount encoded as an XFL (int64_t) on success. A zero (or underflowing) amount returns 0. Errors: DOESNT_EXIST (-5) if the slot is empty; INTERNAL_ERROR (-2) if corrupt; NOT_AN_AMOUNT (-32) if the slot does not hold an amount.

Common failure patterns.

  • Calling it on a non-amount slot → NOT_AN_AMOUNT.

Caveats / notes.

  • Native XAH amounts are normalized to XFL with exponent -6 (drops); IOU amounts use their own mantissa/exponent. Either way you get an XFL you can feed to the float_* functions.
  • Combine with slot_subfield to reach the amount field first (e.g. sfAmount).

Minimal example.

c
int64_t xfl = slot_float(amt_slot);

Practical example.

c
// Extract the Payment Amount as an XFL and compare it to a threshold.
int64_t txn = otxn_slot(0);
int64_t amt = slot_subfield(txn, sfAmount, 0);
int64_t xfl = slot_float(amt);
if (float_compare(xfl, float_set(0, 1000000), COMPARE_LESS) == 1)
    rollback(SBUF("amount below minimum"), __LINE__);
accept(SBUF("ok"), 0);

Related APIs. slot_type, slot_subfield, float_compare.