Micro web-framework for COBOL

I've been interested in getting into this market. Can you point me to these jobs?

There's a nice overview of APL here: http://www.zerobugsandprogramfaster.net/essays/5b.html

FoxPro! :)

I was in the other side of xBase languages, did some dBase III Plus stuff, Clipper Summer '87 followed by OOP with Clipper 5.x, hurray!

High level programming in MS-DOS and were just perfect for crushing out database frontends.

Who said I'm not a mainframe programmer? :)

I've worked for a big financial corp. I was in one of their mainframe teams for a year or so [1]. There's still a lot I don't know but I sure know Rexx is the most fun you can have on a mainframe. It's kind of like the polar opposite of JCL, or getting stuck on a TSO command line.

The first reason why Rexx is great for parsing is the fact that variables equal themselves. There's no "string" data type. If you type "myvar" then that's the name and the contents of your variable (unless you assign it another value):

  DO INDEX = 1 TO 10 BY 2
  SAY HELLO
  END
  
  /* Outputs:
     HELLO
     HELLO
     HELLO
     HELLO
     HELLO
     ***  
   */

Skipping the assignment reduces clutter and makes it very easy to see what you're dealing with. Unless you mess it up later, obviously.

Second, for parsing, Rexx has a keyword instruction called ...(drumroll)... PARSE that essentially implements pattern-matching, of some sort, probably as a regular automaton like regexes but without the regex syntax which is actually really nice. Instead, you define a pattern as a string with literals and variables and the special symbol '.' (a period) to indicate any token, (that's similar to the regex '.' but it matches between spaces).

Here's an example from my notes from that time (spaces delimit literals and variables) [2]:

  /* Fun with patterns at the REXXREPL*/ 
  BANDS = 'SLAYER, BATHORY, MOTORHEAD, VENOM'
  PARSE VAR BANDS ABAND ', ' BEST ', ' REST  
  SAY ABAND                                  
   SLAYER                                    
  SAY BEST                                   
   BATHORY                                   
  SAY REST                                   
   MOTORHEAD, VENOM                          
  PARSE VAR BANDS . ', ' BEST ', ' REST /* Skipped Slayer */
  SAY BEST                                 
   BATHORY                                 
  SAY REST                                 
   MOTORHEAD, VENOM

You can also use numbers to indicate positions in a string (absolute, in the example below, but there's also relative ones):

  DIGITS = '11001011'                        
  PARSE VAR DIGITS FIRSTTWO 3 NEXTFOUR 7 LAST
  SAY FIRSTTWO                               
   11                                        
  SAY NEXTFOUR                               
   0010                                      
  SAY LAST                              
   11     

On top of that, Rexx has "compound variables", a data structure that (to me) resembles a tree and lets you compose hierarchical structures. For instance, here's part of a program that reads in JCL files (formatted to a standard format with another Rexx program so that everything of the same kind is in the same column) and stores their DD, dataset, step and program names in such a structure:

  /*PARSE JOBNAME OFF FIRST LINE IN JCL FILE*/                           
  PARSE VAR CA.1 '//' JOBNAME .                                          
                                                                         
  /*PARSE OTHER NAMES INTO A STEM CALLED 'MATCHES.'                      
  EACH TYPE OF NAME GOES INTO ITS OWN TAIL                               
  TAILS FOR DDNAMES AND DATASET NAMES ARE INDEXED IN TANDEM              
  SAME FOR TAILS WITH STEP AND PROGRAM NAMES                             
                                                                         
  IN OTHER WORDS, MATCHES. IS STRUCTURED AS FOLLOWS:                     
  TAIL INDEX           CONTENTS                                          
  ----------           --------                                          
  MATCHES.DDNAMES.N    N'TH DD NAME FOUND IN JCL FILE                    
  MATCHES.DSNAMES.N    DATASET NAME FOR N'TH DD NAME                     
  MATCHES.STEPNAMES.M  N'TH STEP NAME                                    
  MATCHES.PROGNAMES.M  PROGRAM NAME FOR N'TH STEP NAME                   
                                                                         
  SO, TO GET THE DATASET NAME THAT CORRESPONDS                           
  TO THE 5TH DD AND DATASET NAME                                         
  FOUND IN THE JCL FILE, YOU LOOK INTO:                                  
      MATCHES.DDNAMES.5                                                  
      MATCHES.DSNAMES.5                                                  
  */                                                                     
  DO INDEX = 2 TO CA.0 BY 1                                              
      PARSE VAR CA.INDEX '//' DDNAME . 'DSN=' DSNAME ','                 
      /* IF DD NAME IS EMPTY, DON'T ASSUME DDNAME='DD'*/                 
      IF DDNAME = 'DD' THEN                                              
          DDNAME = ''                                                    
      PARSE VAR CA.INDEX '//' STEPNAME . 'EXEC' PROGNAME ','             
  IF DSNAME ¬= ''                                                        
     THEN                                                                
         MATCHES.DDNAMES.INDEX = DDNAME                                  
         MATCHES.DSNAMES.INDEX = DSNAME                                  
  IF PROGNAME ¬= ''                                                      
     THEN                                                                
         MATCHES.STEPNAMES.INDEX = STEPNAME                              
         MATCHES.PROGNAMES.INDEX = PROGNAME                              
  END                                                                    

(The above will probably make more sense if you've seen a jcl script before).

The point is that all of that is very hard to do with COBOL, and, I believe, impossible with JCL [3]. In Rexx on the other hand, it's a doozy.

I also note that all of the above is nice to have in any language and that not very many of the languages popular outside of mainframes let you parse strings that easily, without explicitly calling a regex library or such.

_______________

[1] I raised hell until they put me in one of those teams. I could get plenty of experience with Spring and Hibernate outside of that corp. Since I was there, I figured I might as well learn something I couldn't learn anywhere else as easily. Still, people looked to me as if I was mad. "You want to be on a mainframe team? Why?".

Dude. Big computers. Millions of users. What the hell?

[2] Note that the "REXXREPL" in my comment is a Rexx program running on TSO (the Z/OS command line, ish):

  /* REXX INTERPRET */              
  REPLPROMPT = "SAY  '>>'"          
  INTERPRET REPLPROMPT              
  DO FOREVER                        
    PULL USERINPUT                  
    IF USERINPUT = "END" THEN EXIT 0
    INTERPRET USERINPUT ; END       

The INTERPRET instruction is another funky bit of Rexx that's real cool to have on a mainframe.

[3] Though I'm sure there's someone, somewhere still on this planet who would laugh in my face for saying that. But probably no more than four or five people.

I'm continually surprised there's not a widely adopted, xBase variant for the web. It seems so obvious? Maybe there is and I'm just not aware of it.