The Fortress Language Specification - CiteSeerX

lowHalf ():BinaryEndianWordb − 1,bigEndianBytes,bigEndianBits where { b > 0 }
highHalf ():BinaryEndianWordb − 1,bigEndianBytes,bigEndianBits where { b > 0 }
opr ‖ nat m,bool bigEndianSequence
(self,other: BinaryEndianWordb,bigEndianBytes,bigEndianBits):
BinaryEndianLinearEndianSequenceb + 1,bigEndianBytes,bigEndianBits,
2,bigEndianSequence
where {bigEndianSequence = bigEndianBytes }
opr ‖ nat m,bool bigEndianSequence,nat radix,nat q,nat k,nat v
(self,other: NaturalNumeralm,radix, v):
BinaryEndianLinearEndianSequenceb,bigEndianBytes,bigEndianBits,
k + 1,bigEndianSequence
where {bigEndianSequence = bigEndianBytes,radix = 2 q , q · m = k · 2 b }
opr ‖ nat m,bool bigEndianSequence,nat radix,nat q,nat k,nat v
(other: NaturalNumeralm,radix, v,self):
BinaryEndianLinearEndianSequenceb,bigEndianBytes,bigEndianBits,
k + 1,bigEndianSequence
where {bigEndianSequence = bigEndianBytes,radix = 2 q , q · m = k · 2 b }
bitShuffle(other: BinaryEndianWordb,bigEndianBytes,bigEndianBits):
BinaryEndianWordb + 1,bigEndianBytes,bigEndianBits
where { b < maxBinaryWordBitLog }
bitUnshuffle():(BinaryEndianWordb − 1,bigEndianBytes,bigEndianBits,
BinaryEndianWordb − 1,bigEndianBytes,bigEndianBits)
where { b > 0 }
littleEndian():BinaryEndianWordb,false,false
bigEndian():BinaryEndianWordb,true,true
end
40.6.1 coercion int r(x:IntegerStaticr) where { −2 b−1 ≤ r < 2 b }
An static integer may be coerced to a binary endian word exactly as if it were coerced to a plain binary word of the
same size; the endian numbering of the bytes and bits does not affect which binary word value is produced from the
static integer.
40.6.2 opr [j: IndexInt] : BinaryEndianWord1,bigEndianBytes,bigEndianBits
throws { IndexOutOfBoundsException }
40.6.3 opr nat k[j: IntegerStatick] : BinaryEndianWord1,bigEndianBytes,bigEndianBits
where { k < 2 b }
Subscripting returns bit j of this binary endian word. The numbering of the bits is dictated by bigEndianBits .
Indexing is zero-origin; an IndexOutOfBoundsException is thrown unless 0 ≤ j < 2 b . If the subscript is a static
expression, then its validity is checked statically, and no exception will occur at run time.
∧
property ∀(v) v j = (if bigEndianBits then v.bit(2 b − 1 − j) else v.bit(j) end)
j←0#2 b
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