Changes planned in Qgate 0.3

Script API changes

Some functions in qgate.script API will be renamed.

• The first letters of some function names are capitalized.

• An operator, release_qreg() is renamed to RelaseQreg().

0.1, 0.2.x	0.3 and above
ctrl	Ctrl
measure	Measure
prob	Prob
if_	If
barrier	Barrier
reset	Reset

One can use updated API with Qgate 0.2.1 or later by importing qgate.script.script2.*

# to use script API from 0.3.
import qgate.script.script2.*

Source code updater is included in 0.2.1 as a module, qgate.tools.update_script. Below is example usages.

# update.  Original source files are saved as *.py.org
$ python -m qgate.tools.update_script file1.py file2.py ...

# update and overwrite.
# Original files are overwritten by updated script files.
$ python -m qgate.tools.update_script -o file1.py file2.py ...

if_ clause

if_ clause will be changed not to accept function as cond, but accept a list of values of 0, 1 and None. If a reference is not measured yet, its referred value is set to None.

qregs = new_qreg(3)

# ... applying gates to qregs

refs = new_references(2)
m0 = measure(refs[0], qregs[0])
m1 = measure(refs[1], qregs[1])
circuit += [m0, m1] # adding measure operations

# function is not accepted from 0.3
# def pred(values) :
#    return values[0] == 0 and values[1] == 1
# circuit += [if_(refs, pred, [X(qregs[2]]]), ...]

# From 0.3, please use the following.
cond = [0, 1]
# X gate is applied when cond matches values pointed by refs.
circuit += [if_(refs, cond, [X(qregs[2]]]), ...]

Gate set consolidation

Built-in gate set will be conslidated.

U1, U2 and U3 gates will be removed from built-in gates, and reimplemented as extensions. These gates will be reimplemented as macro gates (or a gate group).

It does not mean unavailability of these gates from 0.3. Script APIs of U1(), U2() and U3() will be provided in 0.3 and later.

Sampling pool

Sampler class will be added, though details are not decided.