CS320/03 Evolution of Major Languages.
- Check the schedule and syllabus on the WWW site.
- Read Warnings below.
- Study chapter 2
- Try answering the Review Questions at the end chapter 2.
- Bring written questions+answers to 3 of these review questions to class. You can do more if you want. Your graded questions and answers can be used in the final.
| Previous 02 Preliminaries | Study handouts + Chapter 1 | lab02 HTML home page |
| 03 Evolution of Main Languages | Chapter 2 (sections 1-12 +16). | lab03 HTML lab pages |
| Next 04 Syntax: grammars, EBNF, parsing | Chapter 3 sections 1 to 3 + Chapter 4 sections 1 to 3 + XBNF |
Assigned work due
Warnings
C++
In Chapter 2, Figure 2.1 and Figure 2.10 are a little misleading. They give the impression that C++ was finished in the 1980's and ANSI C was derived from C++. In fact, C++ was developed from C in parallel with ANSI C and collected several ideas from ANSI C. The early C++ did not have much effect on ANSI C. ANSI C was completed in 1989. C++ continued to develop until 1998. ANSI C++ was drafted in 1997. ANSI/ISO C++ was finished in 1998. See the diagram below:
COBOL
I've never known a real COBOL programmer who wrote "PICTURE IS". We all
wrote the shorter "PIC". We always omitted stuff like "IS", "LABEL RECORDS
ARE STANDARD", and "RECORD SIZE IS <blah>". The compiler worked these out
for us.
Ada
My memory of the Ada design process was that both PL/1 and Pascal where
used as the basis of the early designs. Certainly PL/I was the basis of one
of the 17 early designs even if it didn't make it into the final four.
APL
The book omits a later development! APL finally escaped the "IBM Golf
Ball with Greek letters" environment. There is language called J
[ wiki?JayLanguage ]
that is
the direct descendent of APL that works on ASCII/DOS systems.
SNOBOL
This lead directly to a strange semi-procedural language called
ICON. The idea of string processing by substitutions re-emerges in UNIX
interpreted languages (sh, csh, ksh, bash, ...) and tools like ed, sed, and
awk. This line of evolution leads to Perl, PHP, Ruby, and Python.