Graphix OpenQASM Parser

graphix-qasm-parser is a plugin for the Graphix library that parses OpenQASM circuit specifications into graphix.transpiler.Circuit objects, which can then be transpiled into MBQC patterns.

It is distributed as a separate plugin because it depends on openqasm-parser.

Installation

pip install https://github.com/TeamGraphix/graphix-qasm-parser.git

Usage

Parsing a string:

from graphix_qasm_parser import OpenQASMParser

s = """
    include "qelib1.inc";
    qubit q;
    rz(5*pi/4) q;
"""
parser = OpenQASMParser()
circuit = parser.parse_str(s)
pattern = circuit.transpile().pattern
print(pattern)

Parsing a file:

circuit = parser.parse_file("my_circuit.qasm")

Supported Specification

Qubits

• Single-qubit registers: qubit q, or the old syntax qreg q.

• Qubit register arrays: qubit[n] q, or the old syntax qreg q[n].

Classical bits

• Single-bit registers: bit b, or the old syntax creg b.

• Bit register arrays: bit[n] b, or the old syntax creg q[n].

Supported Gates

OpenQASM gate	Graphix instruction
h	H
s	S
sdg	SDG
t	T
tdg	TDG
sx	SX
sxdg	SXDG
id	I
x	X
y	Y
z	Z
U	U
p	P
rx	RX
ry	RY
rz	RZ
swap	SWAP
cx	CNOT
cy	CY
cz	CZ
cu	CU
cp	CP
crx	CRX
cry	CRY
crz	CRZ
cswap	CSWAP
ccx	CCX
gphase	GPHASE

Expressions

Expressions with arithmetic operators (+, -, *, /, %) are supported. The constant pi (or π) is defined.

Compile-time constants can be defined and used in expressions.

Gate definitions

User gates can be defined with gate name(parameters) qubits { ... }.

Measurements

Measurements of the form bit = measure qubit;, or the old syntax measure qubit -> bit, are supported.

Both arguments must be registers of the same size, or both must be bit/qubit types.