#Conditionals

Reject invalid paths first and keep the successful transformation visible.

#Branching

#Why

Using an exception to distinguish success from failure hides a normal domain alternative from the return type.

#Rules

• MUST use early-return guards for invalid preconditions. [review]

• MUST handle closed domain alternatives explicitly with structural matching or typed guard branches. [review]

• MUST avoid authored raise, try/except, and unchecked Result extraction for branching. [review]

• MUST use Result map for successful pure transforms and bind for fallible transforms. [review]

• MUST avoid conditional expressions and deeply nested branches around successful paths. [review]

• MUST configure and verify exhaustiveness checks rather than assume Python match statements are exhaustive. [review]

• MUST keep assertions for tests rather than runtime input validation. [review]

[review]

Syntax checks can reject exception-control-flow nodes. Strict typing and review establish variant handling; Python alone does not enforce exhaustive matching.

#Enforcement

Syntax checks can reject exception-control-flow nodes. Strict typing and review establish variant handling; Python alone does not enforce exhaustive matching.