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=== Internal datatypes === | === Internal datatypes === | ||
{{Main|Internal | {{Main|Internal type}} | ||
Most APLs expose only a small number of scalar types to the user: one or two [[numeric]] types (such as double-precision real or [[complex]] numbers), and a single [[character]] type. However, for performance reasons these types can be implemented internally using various subset types. For example, [[APL\360#Internal types|APL\360 uses]] numeric arrays of 1-bit [[Boolean]]s, 4-byte integers, or 8-byte floating point numbers, but converts between them transparently so that from the user's perspective all numbers behave like 8-byte floats (as this type contains the others). In [[Dyalog APL]] this hierarchy is [[Dyalog APL#Internal types|significantly expanded]], adding 1-byte and 2-byte integers as well as 16-byte [[complex]] numbers containing the other types (however, Dyalog also allows the user access to [[decimal float]]s if requested, which breaks the strict hierarchy). | Most APLs expose only a small number of scalar types to the user: one or two [[numeric]] types (such as double-precision real or [[complex]] numbers), and a single [[character]] type. However, for performance reasons these types can be implemented internally using various subset types. For example, [[APL\360#Internal types|APL\360 uses]] numeric arrays of 1-bit [[Boolean]]s, 4-byte integers, or 8-byte floating point numbers, but converts between them transparently so that from the user's perspective all numbers behave like 8-byte floats (as this type contains the others). In [[Dyalog APL]] this hierarchy is [[Dyalog APL#Internal types|significantly expanded]], adding 1-byte and 2-byte integers as well as 16-byte [[complex]] numbers containing the other types (however, Dyalog also allows the user access to [[decimal float]]s if requested, which breaks the strict hierarchy). | ||