Statements

Every statement is an expression, optionally followed by a modifier, and terminated with a semicolon. The semicolon may be omitted if the statement is the final one in a block.

Execution of expressions can depend on other expressions using one of the modifiers if, unless, while, or until, for example:

expr1 if expr2 ; expr1 until expr2 ; 

The logical operators | |, & &, or ? : also allow conditional execution:

expr1 | | expr2 ; expr1 ? expr2 : expr3 ; 

Statements can be combined to form a block when enclosed in { }. block s may be used to control flow:

• if (expr) block [ [ elsif (expr) block...] else block ]

  unless (expr) block [ else block ]

  [ label: ] while (expr) block [ continue block ]

  [ label: ] until (expr) block [ continue block ]

  [ label: ] for ( [ expr ] ; [ expr ] ; [ expr ] ) block

  [ label: ] foreach var(dagger) (list ) block

  [ label: ] block [ continue block ]

Program flow can be controlled with:

• goto label
• Continue execution at the specified label.
• last [ label ]
• Immediately exits the loop in question. Skips continue block.
• next [ label ]
• Starts the next iteration of the loop.
• redo [ label ]
• Restarts the loop block without evaluating the conditional again.

Special forms are:

do block while expr ; do block until expr ; 

which are guaranteed to perform block once before testing expr, and

do block 

which effectively turns block into an expression.