Formatting Rules

This document defines the formatting rules for qasmfmt. Rules are based on analysis of examples from the official OpenQASM repository.

1. Version Declaration

// Before
OPENQASM  3.0;

// After
OPENQASM 3.0;

• Single space between OPENQASM and version number

2. Include Statement

// Before
include"stdgates.inc";

// After
include "stdgates.inc";

• Single space between include and file path

3. Declarations

3.1 Qubit Declaration

// Before
qubit[2]q;
qubitq;

// After
qubit[2] q;
qubit q;

• No space between type and [
• Single space between ] and identifier
• Single space between type and identifier (when no array)

3.2 Classical Bit Declaration

// Before
bit[4]c;
bit c=0;

// After
bit[4] c;
bit c = 0;

• Same rules as qubit declaration
• Spaces around = for initialization

3.3 Constant/Variable Declaration

// Before
const int[32]n=3;

// After
const int[32] n = 3;

4. Gate Calls

4.1 Basic Gates

// Before
hq[0];

// After
h q[0];

• Single space between gate name and arguments

4.2 Multiple Arguments

// Before
cxq[0],q[1];

// After
cx q[0], q[1];

• Single space after comma
• No space before comma

4.3 Parameterized Gates

// Before
rz(pi/4)q[0];
cphase(pi/2)q[0],q[1];

// After
rz(pi / 4) q[0];
cphase(pi / 2) q[0], q[1];

• No space between gate name and (
• Spaces around operators inside parameters
• Single space between ) and arguments

5. Operators

5.1 Arithmetic Operators

// Before
pi/4+pi/8

// After
pi / 4 + pi / 8

• Spaces around +, -, *, /

5.2 Comparison Operators

// Before
c==1
n!=0

// After
c == 1
n != 0

• Spaces around ==, !=, <, >, <=, >=

5.3 Logical Operators

// Before
a&&b
c||d

// After
a && b
c || d

5.4 Assignment Operator

// Before
c=measure q;

// After
c = measure q;

6. Control Flow

6.1 If Statement

// Before
if(c==1)x q;
if(c==1){x q;}

// After
if (c == 1) x q;
if (c == 1) { x q; }

• Single space between if and (
• Single space between ) and statement/{

6.2 If-Else Statement

if (c == 1) {
  x q;
} else {
  z q;
}

• Single space between } and else
• Single space between else and {

6.3 While Statement

// Before
while(flags!=0){...}

// After
while (flags != 0) {
  ...
}

6.4 For Statement

for int i in [0:n] {
  ...
}

7. Gate Definition

// Before
gate mygate(theta)q{rz(theta)q;h q;}

// After
gate mygate(theta) q {
  rz(theta) q;
  h q;
}

• Single space between gate and gate name
• Single space between ) and qubit arguments
• Single space between arguments and {
• Body indented by 2 spaces
• } on its own line

8. Subroutine Definition (def)

// Before
def myfunc(qubit q)->bit{bit b;measure q->b;return b;}

// After
def myfunc(qubit q) -> bit {
  bit b;
  measure q -> b;
  return b;
}

• Spaces around ->
• Body indented by 2 spaces

9. Measure Statement

9.1 Assignment Form

// Before
c=measure q;

// After
c = measure q;

9.2 Arrow Form

// Before
measure q->c;

// After
measure q -> c;

• Spaces around ->

10. Barrier / Reset

barrier q;
reset q;

• Single space between keyword and arguments

11. Indentation

• Indent size: 2 spaces (default)
• Style: Spaces only (no tabs)

gate mygate q {
  h q;
  if (c == 1) {
    x q;
  }
}

12. Blank Lines

12.1 After Include

OPENQASM 3.0;
include "stdgates.inc";

qubit q;

• One blank line after include block

12.2 Around Gate/Def Definitions

qubit q;

gate mygate q {
  h q;
}

h q;

• One blank line before and after gate/def definitions

12.3 Consecutive Blank Lines

• Multiple consecutive blank lines are collapsed to one

13. Trailing

13.1 Trailing Whitespace

• Trailing whitespace on each line is removed

13.2 Trailing Newline

• Single newline at end of file (default)

Rule Summary