Command formats are designed to simplify notation for the most popular formats. To achieve this, several parameter name identification mechanism are implemented,
Parameter is identified explicitly by name on command line:
name=value
barcode left=3.4, bottom=0.5, value=”123456”
Parameter is identified implicitly by the position of the parameter on the command line.
The unnamed text ”123456” as the last parameter of barcode command is
a value.
Left and top offsets are first and second values
text 0.4, 0.5, ”123456”
Parameter is identified defined implicitly by matching the value to the expected type. The typical use is to set enumerated vales. In command formats such usage is identified by the absence of a parameter name (e.g. unit command) or a command name in [] (e.g. output command, onexists parameter)
Enumerated parameter in the output command.
output append, “output.pdf”
A parameter group consists of several parameters (sub-parameters) separated by a colon character ‘:’. They parameters of the group are identified as described in Parameter position and Parameter value identification, however, the identification is applied not to command line, but to the value of a single parameter.
Font parameter group in text command
text left=3.4, bottom=0.5, font=”Helvetica:bold:10”, ”123456”
Font face (Helvetica)is always the first parameter in the group
Font size (10)is a numeric value
Font style (bold)matches on of valid font style values