The COMIS compiler

This chapter gives a brief description of the COMIS syntax. Only the main differences between the COMIS syntax and standard Fortran 77 will be discussed.

The COMIS system language is an almost full implementation of Fortran 77. As the user is working in a realtime environment, some simplifications of the language syntax (in addition to the standard one) are also available: short forms for key-words (CHAR instead of CHARACTER and so on) and a free source code format.

The main differences between the COMIS syntax and standard Fortran77 are:

• COMIS does not accept:
  • character functions;
  • statement functions;
  • INTRINSIC statements;
  • ENTRY statements;
  • BLOCK DATA statements.
• COMIS does not allow a character type variable to be equivalenced with another character variable.
• A type declaration statement, which define the data type of common block name's, must precede the COMMON statement.
• The logical operators .EQV. and .NEQV. are not included in COMIS.
• COMIS does not allow a character expression and an alternate return specifiers as actual arguments.

• The source format
• Data types and constants
• Declarations
• Other language elements
• Programs