Control flow

Informative guide. This Book page explains Beskid but does not define the standard. For normative requirements, use the Beskid Standard.

Control flow is how programs admit they have choices. Beskid expects you to make those choices explicit enough for the analyzer to follow.

if

Standard conditional binding: exact grammar in lexical and syntax. Do not use if to simulate nullable checks; narrow Option<T> with match.

match

match is the honest tool for enums and Option<T>:

• Exhaustive arms are a feature, not bureaucracy
• Combine with enums and match for algebraic types

flowchart TD
  accTitle: Match arms
  accDescr: A match on an enum or Option dispatches to one arm, and the arms must be exhaustive.
  E[enum or Option] --> M[match]
  M --> A1[arm 1]
  M --> A2[arm 2]
  M --> AN[arm n - exhaustive]

Loops and fibers

Iteration and concurrency primitives live under evaluation features (fibers and spawn etc.). This tutorial does not pretend to be the concurrency bible. Read spec before spawning threads because a blog post said async.

Control flow vs effects

Branching across contract boundaries may interact with effect tracking. When in doubt, run beskid dev syntax analyze and read the diagnostic rather than guessing.

Next

Read a diagnostic