All parsing instructions assign parts of the source string to the variables named in the template. The following table summarizes where the source string comes from.
Table 9-1. Parsing Source Strings
| Instruction | Where the source string comes from |
|---|---|
| ARG | Arguments you list when you call the program or arguments in the call to a subroutine or function. |
| PARSE ARG | Arguments you list when you call the program or arguments in the call to a subroutine or function. |
| PARSE LINEIN | Next line in the default input stream. |
| PULL | The string at the head of the external data queue. (If the queue is empty, it uses default input, typically the terminal.) |
| PARSE PULL | The string at the head of the external data queue. (If the queue is empty, it uses default input, typically the terminal.) |
| PARSE SOURCE | System-supplied string giving information about the executing program. |
| PARSE VALUE | Expression between the keywords VALUE and WITH in the instruction. |
| PARSE VAR name | Parses the value of name. |
| PARSE VERSION | System-supplied string specifying the language, language level, and (three-word) date. |