How are created programming languages: variable declaration
Programming languages like to be different. Example: simply declaring a variable.
In this second part of the article: How to create a programming language, this time we are studying how variables are declared. It seems that two lines were followed, that of Pascal and that of C, also with a bit of BASIC.
Pascal language (1970): Very formal, it was estimated that combining declaration and initialization, that's too much at once, under the inspiration of Basic (see below).
var x : Integer; x:= 10;
Language C (1972), C++ (1980), Java (1994), C# (2000): The shorter the better, one seems to think, if we consider the number of programs written in these languages. But under the influence of Pascal (what the author later said to regret), he adds to C the ending semicolon and that will be emulated by Java and C#.
int x = 10;
Erlang (1986): The lesson of C is comprised.
int x = 17;
JavaScript (1995): Like C but without type, and semicolon optional because it is not clear whether it is useful.
var x = 10
OCaml (1996): C found the formula, let's keep it.
int i = 17;
Scala (2004): It would be too simple, back to Pascal but with the shortcut from C, Int instead of Integer and the semicolon is kept.
var x : Int;
Langage Go (2009): We come back to Pascal's syntax but without semicolon which is useless in fact.
var x int = 2
Dart (2011): It does not follow Go and comes back to the simplicity of C. But semicolon is back because it would be too easy otherwise.
int x = 10;
TypeScript (2012): No agreement for simplicity, we return to Pascal, but with a number type such as in Scriptol (I like to note it) ... And the semicolon is back.
var x: number = 6;
In this contest of unnecessary complication , the winner is actually the first.... BASIC (1964).
10 Dim x As Integer 20 x = 10
At this time, one does not imagine to declare a variable and assign it at the same time! But at least there is no semicolon, because we knew from the outset that it is useless ...
Speaking like a coder
What we can do with variables, why not do it with data structures?
Authors of Go did it:
type name struct {
}
This is strongly reminiscent of the record structure of Pascal:
type name = record ... end;
In conclusion, when one want to innovate in creating a programming language, the style of C is dropped and one returns to that of Pascal!