The Quipper System

Safe HaskellNone

QuipperLib.Qureg

Contents

Description

This module provides a data type of quantum registers, as well as associated types of classical and boolean registers.

Synopsis

Quantum registers

type Qureg = Register QubitSource

The type of quantum registers. A quantum register is an array of qubits, indexed by natural numbers in the range from 0 to n-1, where n is the length of the register. The syntax a .!(i) is used to access the ith element of the register a.

The main advantage of a register over a list is constant-time access. The main disadvantage is that registers don't allow easy appending, pattern matching, or recursion.

qureg_of_qulist_te :: Qulist -> QuregSource

Convert a Qulist to a Qureg. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

qulist_of_qureg_te :: Qureg -> QulistSource

Convert a Qureg to a Qulist. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

qureg_length :: Qureg -> IntSource

Return the length of a Qureg.

qinit_register :: [Bool] -> Circ QuregSource

Creates a new quantum register, initialized from a list of booleans. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

qterm_register :: [Bool] -> Qureg -> Circ ()Source

Terminates a quantum register, and assert that its state is as specified by the list of booleans. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

qmeasure_register :: Qureg -> Circ [Bit]Source

Measure a quantum register, yielding a list of Bits.

with_ancilla_reg :: Int -> (Qureg -> Circ a) -> Circ aSource

Temporarily create a quantum register of size n for use as an ancilla. This can be used to introduce an ancilla with a local scope, like this:

 with_ancilla_reg n $ \r -> do {
   <<<code block using ancilla register r>>>
 }

with_ancilla_reg_init :: Boollist -> (Qureg -> Circ a) -> Circ aSource

Like with_ancilla_reg, except also initialize the register as specified by a bit vector. In this case, the argument n is not required, because it equals the length of the bit vector. When the ancilla is terminated at the end of its scope, it is asserted to be in the same state it was prepared in.

qureg_shape :: Int -> QuregSource

Return a piece of shape data to represent an m-qubit quantum register. Please note that the data can only be used as shape; it will be undefined at the leaves.

Bit registers

type Bitreg = Register BitSource

The type of Bit registers. The syntax a .!(i) is used to access the ith element of the register a.

bitreg_of_bitlist_te :: Bitlist -> BitregSource

Turn a bit vector into a bit register. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

bitlist_of_bitreg_te :: Bitreg -> BitlistSource

Turn a bit register into a bit vector. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

bitreg_length :: Bitreg -> IntSource

Return the length of a Bitreg.

Boolean registers

type Boolreg = Register BoolSource

The type of boolean registers.

boolreg_of_boollist_te :: Boollist -> BoolregSource

Turn a bool vector into a bool register. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

boollist_of_boolreg_te :: Boolreg -> BoollistSource

Turn a bool register into a bool vector. The conversion is tail-endian, i.e., r.!(0) holds the tail of the list.

boolreg_length :: Boolreg -> IntSource

Return the length of a Boolreg.

boolreg_of_int_le :: Integral a => Int -> a -> BoolregSource

boolreg_of_int m x: Initialize a bool register directly from an integer x, regarded as a binary string of length m. The conversion is little-endian, i.e., the register holds the least significant digit at index 0.

int_of_boolreg_unsigned_le :: Integral a => Boolreg -> aSource

int_of_boolreg_unsigned_le m r: Turn a bool register into an integer, regarded as a binary string. The conversion is little-endian, i.e., the register holds the least significant digit at index 0. The integer is unsigned.

General registers

data Register x Source

A register is an array of elements of some type x, indexed by natural numbers in the range from 0 to n-1, where n is the length of the register.

(.!) :: Register x -> Int -> xSource

r !.(i): Return the ith element of a register r.