The Use of Symbol-State Tables

This paper describes how a certain kind of table may be used to check the syntax of a string of symbols. In its simplest form, a symbol-state table closely resembles a finite state machine, and requires a large amount of space, often to store duplicated information. By means of the subroutine principle such duplication may be avoided, and recursive use of the table achieved, making possible the checking of recursive structures. When syntax checking is not the only aim, or when checking needs to be performed which is beyond the scope of the table, sections of program coding may be called from the table. Applications have included the writing in FORTRAN of a syntax checker for FORTRAN, and the automatic proof reading of dictionary entries.