The XECUTE command makes an entry in the GT.M invocation stack and executes the argument as GT.M code.
The format of the XECUTE command is:
X[ECUTE]:tvexpr expr[:tvexpr][,...]
The optional truth-valued expression immediately following the command is a command postconditional that controls whether or not GT.M executes the command.
The required expression specifies a fragment of GT.M source code.
The optional truth-valued expression immediately following the argument expression specifies the argument postconditional and controls whether GT.M performs an XECUTE with that argument.
An indirection operator and an expression atom evaluating to a list of one or more XECUTE arguments form a legal argument for an XECUTE.
An explicit or implicit QUIT within the scope of the XECUTE, but not within the scope of any other DO, FOR, XECUTE or extrinsic, returns execution to the instruction following the calling point. This may be the next XECUTE argument or another command. At the end of the code specified by the XECUTE argument expression, GT.M performs an implicit QUIT.
Because XECUTE causes run-time compilation in GT.M, and because it tends to obscure code, use XECUTE only when other approaches clearly do not meet your particular requirement.