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Ada Programming/Libraries/System

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<Ada Programming |Libraries
Computing »Computer Science »Computer Programming »Ada Programming
Ada. Time-tested, safe and secure.
Ada. Time-tested, safe and secure.

Description

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TheSystem package is a standard library package provided with each Ada implementation. It includes implementation and system configuration-dependent definitions. The System package contains a standard set of language-defined (but implementation-dependent) types and named numbers.

Types

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  • Name
  • Address
  • Priority (also Interrupt_Priority and Any_Priority since Ada 95)
  • Bit_Order (since Ada 95)

Constants

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The following named numbers may be set by pragmas. These pragmas may only be used at the start of compilation:

  • System_Name
  • Storage_Unit
  • Memory_Size

The following named numbers are set by the implementation:

  • Null_Address (since Ada 95)
  • Default_Priority (since Ada 95)
  • Default_Bit_Order (since Ada 95)
  • MIN_INT — the smallest value of all predefined integer types (negative).
  • MAX_INT — the largest value of all predefined integer types (positive).
  • MAX_BINARY_MODULUS — the largest power of allowed as the modulus for modular types.
  • MAX_NONBINARY_MODULUS — the largest value allowed as the modulus for modular types.
  • MAX_BASE_DIGITS — the largest number of significant decimal digits in a floating point declaration.
  • MAX_DIGITS — the largest number of significant decimal digits in a floating point declaration without a range specification. This value is at most as large as the previous one.
  • MAX_MANTISSA — the largest possible number of binary digits in the mantissa of fixed point values.
  • FINE_DELTA — The smallest delta allowed in a fixed point value (given a range constraint of -1.0 to 1.0).
  • TICK — the clock period (in seconds).

Child packages

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Standard System packages

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The six untagged System packages are from theISO/IEC 8652:1995(E) standard.

(Ada 2012)
This package is available sinceAda 2012.
(Ada 2022)
This package is available sinceAda 2022.

GNAT System packages

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The following 200 odd packages form the GNAT runtime environment. They are mentioned here as a reference for advanced users. Normal GNAT users should ignore them because they are internal units of the runtime system.

See also

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Wikibook

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Ada 83 Reference Manual

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Ada 95 Reference Manual

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Ada 2005 Reference Manual

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