Strictness Levels

Infr supports three strictness levels that control how aggressively it checks your code. This lets you start permissive and increase strictness as your codebase matures.

Levels

Level	Bare <- behavior	Nullable access without null check	Notes
relaxed (default)	Treated as mutable, no warnings	No diagnostic	Maximum compatibility with existing R
moderate	Treated as mutable, warns "consider const or let"	Warning	Nudges toward explicit intent
strict	Error: must use const or let	Error	Full explicitness required

Configuration

Set the strictness level in infr.toml:

infr.toml

[check]
strictness = "moderate"

Examples

Bare <- assignment

x <- 10

• relaxed: No diagnostic
• moderate: Warning [infr]: Consider using const or let for explicit intent
• strict: Error [infr]: Must use const or let (strict mode)

Nullable access

const val: numeric? <- maybe_get()
val + 1

• relaxed: No diagnostic
• moderate: Warning [infr]: val is numeric? (nullable). Consider checking for NULL first.
• strict: Error [infr]: Cannot pass numeric? to + which expects numeric. Check for NULL first.

Recommended progression

1. Start with relaxed — check your existing R code without changes
2. Move to moderate — get warnings that guide you toward const/let and null checks
3. Adopt strict — enforce full explicitness in mature codebases