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Syntax & Operators

This page summarizes tokens, literals, operators, precedence, and common statement forms as implemented by the v1.0.0 RC parser.

Tokens​

  • Identifiers: [A-Za-z_][A-Za-z0-9_]*
  • Keywords: function, return, if, else, for, while, measure, reset, final, void
  • Types: int, float, char, string, bit, qubit
  • Built-ins: echo and quantum gate names (h, x, y, z, rx, ry, rz, cx)
  • Annotations: @quantum, @tracked
  • Comments: // to end of line

Literals​

  • Integer: 123
  • Float: 3.14f (must include f suffix)
  • Bit: 0b or 1b
  • Char: 'a' (no escapes in v1.0.0)
  • String: "hello" (may span lines; no escapes in v1.0.0)
  • Array: {1, 2, 3}

Operators​

  • Arithmetic: + - * / %
  • Comparison: < <= > >= == != → bit
  • Logical: ! && || → bit
  • Bitwise: ~ & | ^ on bit and bit[]
  • Assignment: = (right-associative in expressions)
  • Postfix: ++ -- (only on int variables)
  • Indexing and call chaining: a[i], f(x,y) are composable: f(a[i])

Statements​

Bloch statements control flow and produce side effects. This section lists each statement with syntax and key rules.

Block​

{ statement* }

Creates a new lexical scope for names and @tracked collection.

Variable declaration​

[final] [@tracked]? type name (= expr)? ;
// Only qubits may be multi-declared
qubit q0, q1; // ok
int a, b;     // error
  • final variables cannot be reassigned.
  • @tracked is allowed on qubit or qubit[] only.

Assignment​

identifier = expr ;

Type-checked assignment. The right side may not be a void result.

Expression statement​

expr ;

Evaluates an expression for side effects, e.g., a function/gate call.

Return​

return ;          // in void functions only
return expr ;     // in non-void functions

All non-void functions must return along all paths.

If / else​

if (expr) { ... } [ else { ... } ]

The condition is any expression yielding a bit (0b/1b is falsy/truthy).

While​

while (expr) { ... }

Loops while the bit condition is truthy.

For​

for ( init? ; condition ; update ) { ... }
// init: declaration or expression statement

Typical C-style loop. condition is evaluated each iteration; update runs after the body.

echo​

echo(expr) ;

Prints a human-friendly representation. Concatenate with +.

reset​

reset q ;

Resets a qubit (or qubit[] element) to |0>.

measure (statement form)​

measure q ;

Collapses a qubit and records an outcome for @tracked. For an immediate bit value, use the expression form: bit b = measure q;.

Conditional statement (? :)​

expr ? statement : statement

Statement-level conditional; unlike many languages, this is not an expression in Bloch. Both branches must be statements.