Overview

Hilmas is a programming language for IBM mainframe environment. It can run on a S/370 or S/390 machine with operating systems like VM, MVS or OS/390 and VSE. It can support five environments in which develop, compile and run programs: CMS (the convesational pseudo-oprating system hosted by VM), TSO (interactive evironment in MVS or OS/390), CICS (in MVS or VSE), MVS batch and VSE batch.

Hilmas peculiarities aren't the instruction set or its purposes; isn't object oriented or innovative language; is a traditional procedural language and its instruction set is vaguely similar to REXX, the mainframe well-known interpreted language. It is a general purpose language with some instructions to facilitate low level programming.
Actually, Hilmas peculiarity is that is a compiled language but it has not a compiler, it is simply a set of assembler macros, and assembler is used to produce a load module. It hasn't a precompiler; writing rules are that of every assembler program but Hilmas ambition is to allow every "normal" programmer to write a "normal" assembler program without any knowledge of assembler.

Hilmas highlights

Hilmas is a structured language, so it is possible build every program without using GO TO instruction because there are flow-control instructions like IF/ELSE/ENDIF, FOR/NEXT, WHILE/ENDWHILE that can be freely nested to reflect every complex logic.

There are some simple instructions, like SAY and INPUT, to display and accept input from a terminal, with the same use in CMS, CICS and TSO; the same SAY and INPUT can be used in batch to write in SYSOUT and read from SYSIN.

Sequential and VSAM files can be managed in TSO, CICS, MVS batch and VSE with the same instructions, by which is possible open, read, write, browse and close all the files needed by the program.

With a plenty of instruction to manipulate strings is possible to obtain a flexibility similar to a REXX program; with conversion instructions is possible to use every numeric format available in mainframe environment; with screen handling instructions is possible dinamically build a 3270 data stream (i.e. a full screen map) in the same manner in CICS, CMS and TSO, and do a full screen portable application.

In a Hilmas program can be defined internal subroutines to improve the structure of a complex application; can be recalled external routines written in every compiled language and a Hilmas program can be written to be recalled as external routine by another program written in every language; an Hilmas program can be recalled by a REXX program and exchange data with it.

If needed, an internal subroutine can be tranformed in a recursive routine (a routine that can recall itself); memory can be dinamically allocated and deallocated and a CICS fullscreen program can be changed from conversational to pseudo-conversational without change not even a line of code. If needed, a CICS program can use EXEC CICS interface, or every program, if needed, can mix native assembler code or user's macros with Hilmas instructions.

Finally, Hilmas can be used to make programs in the old free IBM operating system like VM/370 and MVS.38J, that, together Hercules emulator, can be used to develop mainframe programs in home using a PC with Linux or Windows.