This is an old revision of this page, as edited by NevilleDNZ (talk | contribs) at 02:52, 22 April 2007 (add links to appropriate ALGOL 68 & C++ sections). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 02:52, 22 April 2007 by NevilleDNZ (talk | contribs) (add links to appropriate ALGOL 68 & C++ sections)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)The nearest living sibling to ALGOL 68 may be C++, making this a good comparison candidate:
C++ doesn't have:
- PROC - nested functions,
- OP and PRIO - definable operator symbols and priorities,
- garbage collection,
- use before define,
- formatted transput using complex formatting declarations,
- := - assignment operation symbol (to avoid confusion with equal sign),
- array (and slice operations on them, but in layered libraries),
- automatic UNIONs,
- CASE expressions,
- nonlocal GOTO
- intuitive declaration syntax due to its origin from C.
ALGOL 68 doesn't have:
- public/private access protection,
- overloaded procedures (in contrast to operators),
- explicit memory allocation and deallocation,
- forward declarations,
- textual preprocessing (header files),
- confusion between &- and pointer-style,
- comment lines (only bracketed comments),
- hierarchical classes.
Code Example
Mode declaration
A new mode (type) may be declared using a mode declaration:
int max=99;
mode newtype = struct (
long real a, b, c, short int i, j, k, ref real r
);
This has the similar effect as the following C++ code:
const int max=99;
typedef class {
public: double a, b, c; short i, j, k; float &r;
} newtype;
Note that for ALGOL 68 only the newtype name appears to the left of the equality, and most notably the construction is made - and can be read - from left to right without regard to priorities.
External references
- A comparison of PASCAL and ALGOL 68 - Andrew S. Tanenbaum - June 1977.