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Diffstat (limited to 'api-common.rst')
| -rw-r--r-- | api-common.rst | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/api-common.rst b/api-common.rst index 1526d7ef..ff0e0890 100644 --- a/api-common.rst +++ b/api-common.rst @@ -225,13 +225,27 @@ Signatures Amounts ^^^^^^^ -Amounts of currency are expressed as a JSON object with the following fields: - .. _`tsref-type-Amount`: +Amounts of currency are serialized as a string of the format `<Currency>:<DecimalAmount>`. +Taler treats monetary amounts as fixed-precision numbers. Unlike floating point numbers, +this allows accurate representation of monetary amounts. + +The following constrains apply for a valid amount: + +1. The `<Currency>` part must be at most 12 characters long and may not contain a colon (`:`). +2. The integer part of `<DecimalAmount>` may be at most 2^52 +3. the fractional part of `<DecimalAmount>` may contain at most 8 decimal digits. + +Internally, amounts are parsed into the following object: + +.. note:: + + "EUR:1.50" and "EUR:10" are is a valid amounts. These are all invalid amounts: "A:B:1.5", "EUR:4503599627370501.0", "EUR:1.", "EUR:.1" + .. code-block:: tsref - interface Amount { + interface ParsedAmount { // name of the currency using either a three-character ISO 4217 currency // code, or a regional currency identifier starting with a "*" followed by // at most 10 characters. ISO 4217 exponents in the name are not supported, @@ -438,6 +452,10 @@ Any piece of signed data, complies to the abstract data structure given below. /*From gnunet_crypto_lib.h*/ struct GNUNET_CRYPTO_EccSignaturePurpose { /** + + The following constrains apply for a valid amount: + + * asd * This field is used to express the context in * which the signature is made, ensuring that a * signature cannot be lifted from one part of the protocol |