λ
0.1 - Setup 1.0 - Values 1.1 - Let expressions 1.2 - Basic data types 1.3 - Built-in data structures 1.4 - Functions 1.5 - Fun with Functions 1.6 - Modules 1.7 - Module Signatures 1.8 - Signatures, continued 1.9 - Functors 1.10 - Defining data types 1.11 - Recursive types 2.0 - Pattern matching 2.1 - Exhaustivity checking 2.2 - Value deconstruction 2.3 - Pattern matching in functions 2.4 - Conditional expressions 2.5 - Recursion 2.6 - Higher order functions 2.7 - Infinite loops 2.8 - Chaining expressions for side effects 2.9 - Mutable references 2.10 - While loops 3.0 - Concurrent ML Introduction 3.1 - Spawning a light-weight thread 3.2 - Channels 3.3 - Select 3.4 - Mailboxes 3.5 - IVars 3.6 - MVars 0.0 - Welcome

2.10: While loops

Standard ML has a while loop defined which may be used in place of recursion or higher order functions, wherein one expression is repeated while a condition holds.

Recursion and higher order functions tend to be preferred, as while only makes sense with a mutable condition, and Standard ML tends to prefer immutability.

(* examples/while.sml *)