Loops

Allow the repetition of a group of instructions according to a computation. Every loop body defines its hierarchy level, from the local variables' point of view.

WHILE

(while [BOOL]
   [I0 = INSTRUCTION]
   ...
   [IM = INSTRUCTION]
)

Executes [I0] … [IM] if, and as long as, [BOOL] yields true.

DO WHILE

(do_while [BOOL]
   [I0 = INSTRUCTION]
   ...
   [IM = INSTRUCTION]
)

Executes [I0] … [IM], and does so again as long as, [BOOL] yields true.

FOR

(for
   [PRE = INSTRUCTION]
   [BOOL]
   [POST = INSTRUCTION]

   [I0 = INSTRUCTION]
   ...
   [IM = INSTRUCTION]
)

Executes [PRE], then, if and as long as [BOOL] yields true, executes [I0] … [IM] followed by [POST].

FOR EACH

(foreach [COLLECTION] {String}
   [I0 = INSTRUCTION]
   ...
   [IM = INSTRUCTION]
)

Executes [I0] … [IM] for each member of [COLLECTION], in order. The current member is stored in a new local variable named {String}.

BREAK

(break!)

Exits the current loop.