Conditionals

Evaluate different blocks of Monset code depending on variables using if and else conditional structures.

Syntax

if operand1 == operand2 {
    // block executed if condition is true
} else {
    // block executed if condition is false (optional)
}

• Operators: Supports both equality (==) and inequality (!=) comparisons.
• Operands: Can be double-quoted strings (e.g. "prod"), single-quoted strings (e.g. 'dev'), or bare words (e.g. prod, dev, numbers). They are resolved after variables, allowing comparisons with variable values (e.g. ${ENV}).

Example Usage

Environment-based Port Configuration

@var ENV "prod"

if ${ENV} == "prod" {
    server "80"
} else {
    server "8080"
}

If the ${ENV} variable is "prod", the port 80 is configured; otherwise, it configures port 8080.

Conditional Downloads

@var GET_EXTRA_PAPERS "yes"

downloads {
    https://arxiv.org/pdf/2203.08877 as "primary.pdf"

    if ${GET_EXTRA_PAPERS} == "yes" {
        https://arxiv.org/pdf/2405.01513 as "extra.pdf"
    }
}

Notes

• if blocks can nest inside other blocks like downloads { ... } or group "name" { ... }.
• Conditionals are expanded in a preprocessing pass after variable interpolation has run, so the body can evaluate variables directly.
• The else block is optional.