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0d3fcbaae3
library/*.m:
Delete Erlang foreign code and foreign types.
Delete documentation specific to Erlang targets.
library/deconstruct.m:
Add pragma no_determinism_warning to allow functor_number_cc/3
to compile for now.
library/Mercury.options:
Delete workaround only needed when targetting Erlang.
browser/listing.m:
mdbcomp/rtti_access.m:
Delete Erlang foreign code and foreign types.
673 lines
17 KiB
Mathematica
673 lines
17 KiB
Mathematica
%---------------------------------------------------------------------------%
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% vim: ts=4 sw=4 et ft=mercury
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%---------------------------------------------------------------------------%
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% Copyright (C) 2017-2018 The Mercury team.
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% This file is distributed under the terms specified in COPYING.LIB.
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%---------------------------------------------------------------------------%
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%
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% File: int16.m
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% Main author: juliensf
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% Stability: low.
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%
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% Predicates and functions for dealing with signed 16-bit integer numbers.
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%
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%---------------------------------------------------------------------------%
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:- module int16.
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:- interface.
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:- import_module pretty_printer.
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%---------------------------------------------------------------------------%
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%
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% Conversion from int.
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%
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% from_int(I, I16):
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%
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% Convert an int to an int16.
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% Fails if I is not in [-(2^15), 2^15 - 1].
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%
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:- pred from_int(int::in, int16::out) is semidet.
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% det_from_int(I) = I16:
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%
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% Convert an int to an int16.
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% Throws an exception if I is not in [-(2^15), 2^15 - 1].
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%
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:- func det_from_int(int) = int16.
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% cast_from_int(I) = I16:
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%
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% Convert an int to an int16.
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% Always succeeds, but will yield a result that is mathematically equal
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% to I only if I is in [-(2^15), 2^15 - 1].
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%
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:- func cast_from_int(int) = int16.
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%---------------------------------------------------------------------------%
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%
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% Conversion to int.
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%
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% to_int(I16) = I:
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%
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% Convert an int16 to an int. Since an int can be only 32 or 64 bits,
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% this is guaranteed to yield a result that is mathematically equal
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% to the original.
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%
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:- func to_int(int16) = int.
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% cast_to_int(I16) = I:
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%
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% Convert an int16 to an int. Since an int can be only 32 or 64 bits,
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% this is guaranteed to yield a result that is mathematically equal
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% to the original.
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%
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:- func cast_to_int(int16) = int.
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%---------------------------------------------------------------------------%
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%
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% Change of signedness.
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%
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% cast_from_uint16(U16) = I16:
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%
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% Convert a uint16 to an int16. This will yield a result that is
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% mathematically equal to U16 only if U16 is in [0, 2^15 - 1].
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%
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:- func cast_from_uint16(uint16) = int16.
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%---------------------------------------------------------------------------%
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%
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% Conversion from byte sequence.
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%
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% from_bytes_le(LSB, MSB) = I16:
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%
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% I16 is the int16 whose least and most significant bytes are given by the
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% uint8s LSB and MSB respectively.
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%
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:- func from_bytes_le(uint8, uint8) = int16.
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% from_bytes_be(MSB, LSB) = I16:
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%
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% I16 is the int16 whose least and most significant bytes are given by the
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% uint8s LSB and MSB respectively.
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%
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:- func from_bytes_be(uint8, uint8) = int16.
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%---------------------------------------------------------------------------%
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%
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% Comparisons and related operations.
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%
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% Less than.
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%
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:- pred (int16::in) < (int16::in) is semidet.
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% Greater than.
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%
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:- pred (int16::in) > (int16::in) is semidet.
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% Less than or equal.
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%
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:- pred (int16::in) =< (int16::in) is semidet.
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% Greater than or equal.
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%
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:- pred (int16::in) >= (int16::in) is semidet.
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% Maximum.
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%
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:- func max(int16, int16) = int16.
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% Minimum.
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%
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:- func min(int16, int16) = int16.
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%---------------------------------------------------------------------------%
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%
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% Absolute values.
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%
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% abs(X) returns the absolute value of X.
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% Throws an exception if X = int16.min_int16.
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%
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:- func abs(int16) = int16.
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% unchecked_abs(X) returns the absolute value of X, except that the result
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% is undefined if X = int16.min_int16.
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%
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:- func unchecked_abs(int16) = int16.
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% nabs(X) returns the negative of the absolute value of X.
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% Unlike abs/1 this function is defined for X = int16.min_int16.
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%
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:- func nabs(int16) = int16.
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%---------------------------------------------------------------------------%
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%
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% Arithmetic operations.
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%
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% Unary plus.
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%
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:- func + (int16::in) = (int16::uo) is det.
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% Unary minus.
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%
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:- func - (int16::in) = (int16::uo) is det.
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% Addition.
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%
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:- func int16 + int16 = int16.
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:- mode in + in = uo is det.
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:- mode uo + in = in is det.
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:- mode in + uo = in is det.
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:- func plus(int16, int16) = int16.
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% Subtraction.
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%
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:- func int16 - int16 = int16.
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:- mode in - in = uo is det.
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:- mode uo - in = in is det.
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:- mode in - uo = in is det.
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:- func minus(int16, int16) = int16.
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% Multiplication.
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%
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:- func (int16::in) * (int16::in) = (int16::uo) is det.
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:- func times(int16, int16) = int16.
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% Flooring integer division.
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% Truncates towards minus infinity, e.g. (-10_i16) div 3_i16 = (-4_i16).
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%
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% Throws a `domain_error' exception if the right operand is zero.
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%
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:- func (int16::in) div (int16::in) = (int16::uo) is det.
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% Truncating integer division.
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% Truncates towards zero, e.g. (-10_i16) // 3_i16 = (-3_i16).
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% `div' has nicer mathematical properties for negative operands,
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% but `//' is typically more efficient.
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%
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% Throws a `domain_error' exception if the right operand is zero.
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%
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:- func (int16::in) // (int16::in) = (int16::uo) is det.
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% (/)/2 is a synonym for (//)/2.
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%
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:- func (int16::in) / (int16::in) = (int16::uo) is det.
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% unchecked_quotient(X, Y) is the same as X // Y, but the behaviour
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% is undefined if the right operand is zero.
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%
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:- func unchecked_quotient(int16::in, int16::in) = (int16::uo) is det.
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% Modulus.
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% X mod Y = X - (X div Y) * Y
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%
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% Throws a `domain_error' exception if the right operand is zero.
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%
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:- func (int16::in) mod (int16::in) = (int16::uo) is det.
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% Remainder.
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% X rem Y = X - (X // Y) * Y.
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%
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% Throws a `domain_error/` exception if the right operand is zero.
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%
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:- func (int16::in) rem (int16::in) = (int16::uo) is det.
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% unchecked_rem(X, Y) is the same as X rem Y, but the behaviour is
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% undefined if the right operand is zero.
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%
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:- func unchecked_rem(int16::in, int16::in) = (int16::uo) is det.
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% even(X) is equivalent to (X mod 2i16 = 0i16).
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%
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:- pred even(int16::in) is semidet.
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% odd(X) is equivalent to (not even(X)), i.e. (X mod 2i16 = 1i16).
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%
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:- pred odd(int16::in) is semidet.
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%---------------------------------------------------------------------------%
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%
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% Shift operations.
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%
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% Left shift.
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% X << Y returns X "left shifted" by Y bits.
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% The bit positions vacated by the shift are filled by zeros.
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% Throws an exception if Y is not in [0, 16).
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%
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:- func (int16::in) << (int::in) = (int16::uo) is det.
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% unchecked_left_shift(X, Y) is the same as X << Y except that the
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% behaviour is undefined if Y is not in [0, 16).
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% It will typically be implemented more efficiently than X << Y.
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%
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:- func unchecked_left_shift(int16::in, int::in) = (int16::uo) is det.
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% Right shift.
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% X >> Y returns X "right shifted" by Y bits.
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% The bit positions vacated by the shift are filled by the sign bit.
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% Throws an exception if Y is not in [0, 16).
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%
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:- func (int16::in) >> (int::in) = (int16::uo) is det.
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% unchecked_right_shift(X, Y) is the same as X >> Y except that the
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% behaviour is undefined if Y is not in [0, 16).
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% It will typically be implemented more efficiently than X >> Y.
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%
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:- func unchecked_right_shift(int16::in, int::in) = (int16::uo) is det.
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%---------------------------------------------------------------------------%
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%
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% Logical operations.
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%
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% Bitwise and.
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%
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:- func (int16::in) /\ (int16::in) = (int16::uo) is det.
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% Bitwise or.
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%
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:- func (int16::in) \/ (int16::in) = (int16::uo) is det.
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% Bitwise exclusive or (xor).
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%
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:- func xor(int16, int16) = int16.
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:- mode xor(in, in) = uo is det.
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:- mode xor(in, uo) = in is det.
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:- mode xor(uo, in) = in is det.
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% Bitwise complement.
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%
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:- func \ (int16::in) = (int16::uo) is det.
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%---------------------------------------------------------------------------%
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%
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% Operations on bits and bytes.
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%
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% num_zeros(I) = N:
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%
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% N is the number of zeros in the binary representation of I.
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%
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:- func num_zeros(int16) = int.
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% num_ones(I) = N:
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%
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% N is the number of ones in the binary representation of I.
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%
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:- func num_ones(int16) = int.
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% num_leading_zeros(I) = N:
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%
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% N is the number of leading zeros in the binary representation of I,
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% starting at the most significant bit position.
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% Note that num_leading_zeros(0i16) = 16.
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%
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:- func num_leading_zeros(int16) = int.
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% num_trailing_zeros(I) = N:
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%
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% N is the number of trailing zeros in the binary representation of I,
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% starting at the least significant bit position.
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% Note that num_trailing_zeros(0i16) = 16.
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%
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:- func num_trailing_zeros(int16) = int.
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% reverse_bytes(A) = B:
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%
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% B is the value that results from reversing the bytes in the binary
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% representation of A.
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%
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:- func reverse_bytes(int16) = int16.
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% reverse_bits(A) = B:
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%
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% B is the is value that results from reversing the bits in the binary
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% representation of A.
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%
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:- func reverse_bits(int16) = int16.
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%---------------------------------------------------------------------------%
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%
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% Limits.
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%
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:- func min_int16 = int16.
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:- func max_int16 = int16.
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%---------------------------------------------------------------------------%
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%
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% Prettyprinting.
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%
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% Convert an int16 to a pretty_printer.doc for formatting.
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%
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:- func int16_to_doc(int16) = pretty_printer.doc.
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%---------------------------------------------------------------------------%
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%---------------------------------------------------------------------------%
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:- implementation.
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:- import_module exception.
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:- import_module int.
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:- import_module require.
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:- import_module string.
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:- import_module uint.
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:- import_module uint16.
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%---------------------------------------------------------------------------%
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from_int(I, I16) :-
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I >= -32_768,
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I =< 32_767,
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I16 = cast_from_int(I).
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det_from_int(I) = I16 :-
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( if from_int(I, I16Prime) then
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I16 = I16Prime
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else
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error($pred, "cannot convert int to int16")
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).
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:- pragma foreign_proc("C",
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cast_from_int(I::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail,
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does_not_affect_liveness],
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"
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I16 = (int16_t) I;
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").
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:- pragma foreign_proc("C#",
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cast_from_int(I::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = (short) I;
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").
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:- pragma foreign_proc("Java",
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cast_from_int(I::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = (short) I;
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").
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%---------------------------------------------------------------------------%
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:- pragma foreign_proc("C",
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to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail],
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"
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I = I16;
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").
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:- pragma foreign_proc("C#",
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to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I = I16;
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").
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:- pragma foreign_proc("Java",
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to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I = I16;
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").
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:- pragma foreign_proc("C",
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cast_to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail],
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"
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I = I16;
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").
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:- pragma foreign_proc("C#",
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cast_to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I = I16;
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").
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:- pragma foreign_proc("Java",
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cast_to_int(I16::in) = (I::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I = I16;
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").
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%---------------------------------------------------------------------------%
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:- pragma foreign_proc("C",
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cast_from_uint16(U16::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail,
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does_not_affect_liveness],
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"
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I16 = U16;
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").
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:- pragma foreign_proc("C#",
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cast_from_uint16(U16::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = (short) U16;
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").
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:- pragma foreign_proc("Java",
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cast_from_uint16(U16::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = U16;
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").
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%---------------------------------------------------------------------------%
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:- pragma foreign_proc("C",
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from_bytes_le(LSB::in, MSB::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe, will_not_modify_trail],
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"
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unsigned char *int16_bytes = (unsigned char *) &I16;
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#if defined(MR_BIG_ENDIAN)
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int16_bytes[0] = MSB;
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int16_bytes[1] = LSB;
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#else
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int16_bytes[0] = LSB;
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int16_bytes[1] = MSB;
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#endif
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").
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:- pragma foreign_proc("Java",
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from_bytes_le(LSB::in, MSB::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = (short) (MSB << java.lang.Byte.SIZE | (LSB & 0x00ff));
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").
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:- pragma foreign_proc("C#",
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from_bytes_le(LSB::in, MSB::in) = (I16::out),
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[will_not_call_mercury, promise_pure, thread_safe],
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"
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I16 = (short) (MSB << 8 | (LSB & 0x00ff));
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").
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from_bytes_be(MSB, LSB) =
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from_bytes_le(LSB, MSB).
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%---------------------------------------------------------------------------%
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% The comparison operations <, >, =< and >= are builtins.
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max(X, Y) =
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( if X > Y then X else Y ).
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min(X, Y) =
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( if X < Y then X else Y ).
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%---------------------------------------------------------------------------%
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abs(Num) =
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( if Num = int16.min_int16 then
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func_error($pred, "abs(min_int16) would overflow")
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else
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unchecked_abs(Num)
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).
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unchecked_abs(Num) =
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( if Num < 0i16 then
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0i16 - Num
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else
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Num
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|
).
|
|
|
|
nabs(Num) =
|
|
( if Num > 0i16 then
|
|
-Num
|
|
else
|
|
Num
|
|
).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
% The operations + and - (both hand binary), plus, minus, *, and times
|
|
% are builtins.
|
|
|
|
X div Y = Div :-
|
|
Trunc = X // Y,
|
|
( if
|
|
( X >= 0i16, Y >= 0i16
|
|
; X < 0i16, Y < 0i16
|
|
; X rem Y = 0i16
|
|
)
|
|
then
|
|
Div = Trunc
|
|
else
|
|
Div = Trunc - 1i16
|
|
).
|
|
|
|
:- pragma inline('//'/2).
|
|
X // Y = Div :-
|
|
( if Y = 0i16 then
|
|
throw(domain_error("int16.'//': division by zero"))
|
|
else
|
|
Div = unchecked_quotient(X, Y)
|
|
).
|
|
|
|
:- pragma inline('/'/2).
|
|
X / Y = X // Y.
|
|
|
|
X mod Y = X - (X div Y) * Y.
|
|
|
|
:- pragma inline(rem/2).
|
|
X rem Y = Rem :-
|
|
( if Y = 0i16 then
|
|
throw(domain_error("int16.rem: division by zero"))
|
|
else
|
|
Rem = unchecked_rem(X, Y)
|
|
).
|
|
|
|
:- pragma inline(even/1).
|
|
even(X) :-
|
|
(X /\ 1i16) = 0i16.
|
|
|
|
:- pragma inline(odd/1).
|
|
odd(X) :-
|
|
(X /\ 1i16) \= 0i16.
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
% The operations unchecked_left_shift and unchecked_right_shift are builtins.
|
|
|
|
X << Y = Result :-
|
|
( if cast_from_int(Y) < 16u then
|
|
Result = unchecked_left_shift(X, Y)
|
|
else
|
|
Msg = "int16.(<<): second operand is out of range",
|
|
throw(domain_error(Msg))
|
|
).
|
|
|
|
X >> Y = Result :-
|
|
( if cast_from_int(Y) < 16u then
|
|
Result = unchecked_right_shift(X, Y)
|
|
else
|
|
Msg = "int16.(>>): second operand is out of range",
|
|
throw(domain_error(Msg))
|
|
).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
num_zeros(U) = 16 - num_ones(U).
|
|
|
|
num_ones(I16) = N :-
|
|
U16 = uint16.cast_from_int16(I16),
|
|
N = uint16.num_ones(U16).
|
|
|
|
num_leading_zeros(I16) = N :-
|
|
U16 = uint16.cast_from_int16(I16),
|
|
N = uint16.num_leading_zeros(U16).
|
|
|
|
num_trailing_zeros(I16) = N :-
|
|
U16 = uint16.cast_from_int16(I16),
|
|
N = uint16.num_trailing_zeros(U16).
|
|
|
|
%---------------------%
|
|
|
|
:- pragma foreign_proc("C",
|
|
reverse_bytes(A::in) = (B::out),
|
|
[will_not_call_mercury, promise_pure, thread_safe],
|
|
"
|
|
B = (int16_t) MR_uint16_reverse_bytes((uint16_t)A);
|
|
").
|
|
|
|
:- pragma foreign_proc("C#",
|
|
reverse_bytes(A::in) = (B::out),
|
|
[will_not_call_mercury, promise_pure, thread_safe],
|
|
"
|
|
B = (short) ((A & 0x00ffU) << 8 | (A & 0xff00U) >> 8);
|
|
").
|
|
|
|
:- pragma foreign_proc("Java",
|
|
reverse_bytes(A::in) = (B::out),
|
|
[will_not_call_mercury, promise_pure, thread_safe],
|
|
"
|
|
B = java.lang.Short.reverseBytes(A);
|
|
").
|
|
|
|
%---------------------%
|
|
|
|
reverse_bits(I16) = RevI16 :-
|
|
U16 = uint16.cast_from_int16(I16),
|
|
RevU16 = uint16.reverse_bits(U16),
|
|
RevI16 = int16.cast_from_uint16(RevU16).
|
|
|
|
:- pragma foreign_proc("Java",
|
|
reverse_bits(A::in) = (B::out),
|
|
[will_not_call_mercury, promise_pure, thread_safe],
|
|
"
|
|
B = (short) (java.lang.Integer.reverse(A << 16) & 0xffff);
|
|
").
|
|
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
min_int16 = -32_768_i16.
|
|
|
|
max_int16 = 32_767_i16.
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
int16_to_doc(X) = str(string.int16_to_string(X)).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
:- end_module int16.
|
|
%---------------------------------------------------------------------------%
|