OpenQASM 3.0 Style Analysis

Analysis Date: January 2026

This document summarizes the analysis of examples from the official openqasm/openqasm repository.

Analyzed Files

• teleport.qasm
• qft.qasm
• rb.qasm
• gateteleport.qasm
• rus.qasm
• inverseqft1.qasm

Observed Style Patterns

1. Comments

// Line comment
/* Block comment */

2. OPENQASM Declaration

OPENQASM 3;  // With semicolon, without dot

Sometimes omitted (some examples start with include)

3. Include Statement

include "stdgates.inc";

• Space between include and filename

4. Declarations

qubit[4] q;
bit[4] c;
const int[32] n = 3;

• No space between type and [
• Space between ] and identifier

5. Gate Calls

h q[0];
cx q[0], q[1];
cphase(pi / 2) q[1], q[0];
rz(pi/4) a;

• Space between gate name and arguments
• Space after comma
• Inconsistent spacing inside parameters (pi / 2 and pi/4 both appear)

6. Gate/Def Definitions

gate post q { }

def segment(qubit[2] anc, qubit psi) -> bit[2] {
  bit[2] b;
  reset anc;
  ...
  return b;
}

• Space before braces
• Body indented by 2 spaces

7. If Statement

if(c0==1) z q[2];
if(c1==1) { x q[2]; }
if (r == 1) z q;

Inconsistent points:

• if( vs if ( - presence/absence of space
• Spacing around ==
• Braces for single statements

8. While Statement

while(int[2](flags) != 0) {
  flags = segment(ancilla, input_qubit);
}

9. Measure

c0 = measure q[0];     // Assignment form
measure q -> c;        // Arrow form

Both forms are used

10. Barrier

barrier q;

Inconsistent Points (to be unified by qasmfmt)

Proposed qasmfmt Rules

Confirmed Rules (consistent in official examples)

✓ Space after include
✓ Space between type and identifier (qubit[2] q)
✓ Space between gate name and arguments (h q)
✓ Space after comma
✓ 2-space indent inside blocks
✓ Space before braces

Normalization Rules (qasmfmt will enforce)

→ Space after if ( and while (
→ Spaces around comparison operators (== != < >)
→ Spaces around arithmetic operators (+ - * /)
→ Spaces around assignment operator (=)

Configurable (future)

? Indentation: 2 or 4 spaces
? Maximum line width: 80 or 100