Category:M2000 Interpreter: Difference between revisions

M2000 start as an experimental interpreted language, using a Module in Module idea (like a Procedure in Procedure) where each inner Module is closed for modification, but open for expansion, by replacing code at run time. Source code executed as is, without second interpretation of a simple form, although block of code arranged for execution in a manner of consuming code (code which executed deleted, code in a loop kept as a copy for next iteration).

Module's may be Global, or local to other modules. We can define global modules in a module, and all these definitions deleted at the end of module execution. Because we have to execute the definition of a module, we can select definition, or load definition before we call the module. Also modules can be part of object's of type Group. A module can't call itself unless we use Call module_name. The standard call is by using only the name of module. So from a module we can call local modules or global, but we can't call parent module (if isn't global). In a group we can call anything like a module plus the modules of the groups.

We can change a inner module at the calling of a module, see the example: We call inner Beta in two stages. At the second stage we change inner Theta with Theta2. This is the decoration of Beta with Theta as Theta2. This is a temporary decoration because Beta after execution erase any new identifier including Theta. So each time we call Beta, statement Module Theta make this module unless a decoration stop it.

====English Vocabulary====

====Greek Vocabulary====

As we can see from code, some statements are like BASIC, except the use of curly brackets {}. Check the code below. We have a Module (as a Procedure), where we define some functions and some variables, as entities. These entities defined in every call to CheckIt, and erased when execution return from CheckIt. By default every parameter in M2000 pass by value. We define two functions, Alfa() where we set type for parameter x and ExpType$() where we not set type for x, and we wish to return the name of type when we make a call.

double z // new from version 12

Currency Z1=212.12, Z2=323233.12, Z3=223212323323.12

// We can call it again

For small programs, for learning algorithms there is no need to use types, except the major types, Numeric and Strings, plus one more: Integer. Integers can be number types like Long and Integer types, or can be any numeric type using without decimal part. So Integer variables are variables with % suffix on their name. String Variable can use a $ suffix. From version 12 we can use string variables without suffix. Although the interpreter own string functions use suffix $ (like str$()).

A statement Input Alfa$ can input characters for a string or for object typed group with that name. Interpreter implicitly use the appropriate method.