The input in a work window is processed in the following sequence:
Syntactical and semantic check of the input in the statement code column
Evaluation of the data window
Execution of the statement codes entered in the statement code column
Execution of the statements entered in the statement line
If two work windows are present (see also section “Second work window”) then each of the above steps is performed first for the upper and then for the lower work window.
irrespective of the number of work windows, as long as insert or delete statement codes (1..9,I,X,H or E) are present in the statement code column of one of the work windows, only data windows and the statement code are evaluated. First of all, the records are taken over from the data window into the file. The statement code column is then evaluated. The content of the statement line remains unchanged and is not evaluated until none of the above-mentioned statement codes is still specified in any of the work windows. In contrast, if the permanent insert function is active (see statement code I) then this does not prevent the evaluation of the statement line.
If errors occur during processing then the following applies:
If errors are detected while checking the syntax or semantics of the statement code column, the invalid statement codes are overwritten with question marks (
'?') and the further processing of the input is aborted.If errors occur during the evaluation of the data window, for example because it is not possible to split a line with @PAR RENUMBER=OFF, then the statement codes in the affected work window are processed. However, the statement line is not processed and is instead displayed again unchanged. Entries in a second work window, if present, are processed normally.
If errors occur during the processing of statement codes, for example because it is not possible to insert lines with @PAR RENUMBER=OFF, then the remaining statement codes in the affected work window are processed. However, the statement line is not processed and is instead displayed again unchanged. Statement codes in a second work window, if present, are also processed. Here again, the statement line is not executed.
Errors during the processing of entries in the statement line are not detected until statements in the data window or statement codes have already been processed. Statements in a statement sequence continue to be executed until an invalid statement is found. This applies to each work window independently of the other (see also section “Statement line”).
Note
If, when the screen is split, @PAR SPLIT=OFF is entered in the upper statement line and a statement is entered in the lower statement line then @PAR SPLIT=OFF is rejected with an error message.
If the two work windows are displaying the same or overlapping sections of the same work file, then statement codes and statements in the two work windows may affect one another, for example if a line is to be simultaneously deleted in one work window and transferred to the copy buffer in the other.
Users are therefore advised not to work in this way. In contrast, non-overlapping sections from the same work file can be processed simultaneously in two different work windows without difficulty.