Expressions

Expressions in Midio allow you to write small snippets of logic directly inside function inputs. They can be used anywhere a function input is editable and are a powerful way to perform computations or dynamically construct values inline.

What You Can Do with Expressions

Expressions support many of the constructs you'd expect from a general-purpose language:

• Unary and binary operators: Use operators like +, -, *, /, !, and more to perform arithmetic and logical operations.

• Ternary operator: Use the condition ? valueIfTrue : valueIfFalse form to choose between values based on a condition.

• Literals: You can use basic data literals including numbers (42), strings ("hello"), booleans (true, false), objects ({a: 1}), and lists ([1, 2, 3]).

• Use Local Variables: Local variables can be retrieved by prefixing their name with @, e.g. @myVariable.

• Inputs: Add inputs to your expression by simply writing an identifier name (e.g., inputValue). This adds an additional input property underneath the input you placed the expression in.

• Indexing and calls: Use [index] to access list or object properties and () to call functions. Note: Functions must currently be passed in as inputs to be called in expressions.

• String interpolation: Embed expressions inside strings using ${...} syntax. For example: "Hello, ${name}!".

• Call various builtin math functions, like math.cos(1.0), og math.random(0, 10). Following is a list of all builtin functions:

  • math.is_nan(x)

  • math.is_finite(x)

  • math.is_infinite(x)

  • math.is_normal(x)

  • math.cos(angle)

  • math.sin(angle)

  • math.tan(angle)

  • math.acos(x)

  • math.asin(x)

  • math.atan(x)

  • math.atan2(y, x)

  • math.cosh(x)

  • math.sinh(x)

  • math.tanh(x)

  • math.acosh(x)

  • math.asinh(x)

  • math.atanh(x)

  • math.ln(x)

  • math.log2(x)

  • math.log10(x)

  • math.log(base, x)

  • math.exp(x)

  • math.exp2(x)

  • math.pow(base, exponent)

  • math.sqrt(x)

  • math.cbrt(x)

  • math.abs(x)

  • math.hypot(x, y)

  • math.random()

  • math.min(a, b)

  • math.max(a, b)

  • math.clamp(x, min_val, max_val)

  • math.lerp(a, b, t)

  • math.sign(x)

  • math.floor(x)

  • math.ceil(x)

  • math.round(x)

  • math.trunc(x)

  • math.fract(x)

Limitations

Expressions currently cannot be used directly inside object literals—this will be added in a future update. See the working with data guide for more information about how you can work around this limitation for now.