Browse Prior Art Database

Dynamic Syntax

IP.com Disclosure Number: IPCOM000075237D
Original Publication Date: 1971-Aug-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

McKeehan, JB: AUTHOR

Abstract

The ability to dynamically modify syntactically significant characters in statements of a program extends the use of a data processing system to what would otherwise be foreign language systems and allows existing language systems to be treated as subsets. It also allows a user to tailor the syntax of a language to his own purposes.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Dynamic Syntax

The ability to dynamically modify syntactically significant characters in statements of a program extends the use of a data processing system to what would otherwise be foreign language systems and allows existing language systems to be treated as subsets. It also allows a user to tailor the syntax of a language to his own purposes.

To do this, a syntax processor 1 analyzes each statement of a program 2. Processor 1 uses a syntax table 3 that is initially set to the correct syntactic symbols or characters associated with different keywords of the language system. When processor 1 encounters a keyword in a statement, it looks up the correct syntax in table 3 and makes a comparison and either allows the statement or indicates a syntactic error. A DELIMIT statement permits the syntax to be changed. This statement specifies the keyword and the old and new syntax.

In the illustrated examples, table 3 is set so that ( ) (at 4) are the correct syntax associated with a keyword. When statement A is encountered, processor 1 looks up the ( ) in table 3 and determines that the syntax of statement A is correct. Upon encountering statement B, the syntax is changed from ( ) to = by overwriting the current syntax in table 3 at 5 with the new syntax. Thereafter, in subsequent statements in the program, such as statement C, the = symbol is treated as the correct syntax.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]