Variables

The language used 4 kinds of variables:

• predefined variables - These variables concern the current context of the user. In order to distinguish themselves from other variables, they are prefixed by the $ character. The list is given by the table 1.            

  
  

   

  Table 1: Predefined variables

  Name	Type	Description
  $csel	AST	this variable is set when a pattern-matching is successful (mark the beginning of the fortran code matched). It may also be set through the displacement statements (see chapter 7.4) or directly by a selection made by the user in the current fortran window.
  $cstat	AST	this variable is set to the statement containing $csel or to $csel (if it is a statement).
  $cfile	Undocumented	This variable describes the file which contains the current unit.
  $cunit	AST	This variable is the root of the AST which defines the fortran code of the current unit. It allows to acces to several informations (statements, symbol table, forlib, ...)
  $cforlib	Undocumented	This variable allows to access to the current forlib.
  $csymtab	Undocumented	This variable allows to access to the current fortran symbol table. In fact, it is never used since the symbol table can be accessed via the unit (i.e. $cunit)

   
  
  

• pattern variables - Those variables are used in pattern definitions. They can be read in the action field (transformation script) only if they are presented in the pattern definition. In a such case, they are used like pointers on the matched fortran program. According to their specific usage, these variables are prefixed by the ? character.
• local variables - Those variables are local to the script which creates them. They are not declared.
• global variables - Those variables are declared by a GLOBAL   statement at the begining of each script which want to use them.

  $\vartriangleright$ Example 4: A counter of calls of script

   
    SCRIPT hello ()
      GLOBAL call_cpt 
      call_cpt := call_cpt+1 
      PRINT "hello" 
      CALLSCRIPT world() 
    ENDSCRIPT
    
    SCRIPT world ()
      GLOBAL call_cpt 
      call_cpt := call_cpt+1 
      PRINT "world" 
    ENDSCRIPT
    
    SCRIPT main ()
      GLOBAL call_cpt 
      call_cpt := 0 
      CALLSCRIPT hello() 
      PRINT call_cpt 
    ENDSCRIPT