Compiled script instructions can be assembled "on the fly" with opcode and mod byte escape sequences.

OpcodeOrModByteEscape ::= ‘&’ OpcodeOrModByteString ‘;’
NumericEscape ::= ‘&#’ ((‘x’ HexDigit+) | DecimalNumber) ‘;’

It is not expected for I.F. designers to understand the technical nature of opcodes and mod bytes, so direct escaping of such instructions is ill-advised.  However, one type of escape is appropriate for debugging purposes:

&stop;

The "stop" opcode indicates a breakpoint.  The BAR_Services engine control flags on initialization determine how breakpoints are treated during function execution.  By default, breakpoints halt execution in a function body, but the settings can be modified to force BAR to ignore these instructions.

  See also:  [Evaluation and null statements] [The "goto" statement and text labels] [The "return" statement] [The "if" and "else" statements]
[The "for" statement] [The "while" statement] [The "do" statement] [The "switch," "case," and "default" statements]
[The "break" statement] [The "continue" statement] [Opcode and mod byte escape sequences]