Differences

This shows you the differences between two versions of the page.

--- guide:start [2023/04/21 13:35]
rajit [Referencing a process]
+++ guide:start [2023/04/21 13:43] (current)
rajit [Referencing a particular language body]
@@ Line 19: / Line 19: @@
 ==== Referencing a process ====
-Once the ''Act'' pointer has been created, a process (provided in the command-line arguments) within the file can be accessed and expanded:
+Once the ''Act'' pointer has been created, a process (provided in the command-line arguments) within the file can be accessed and expanded (if necessary):
 <code>
 Process *p = a->findProcess (argv[2]);
@@ Line 26: / Line 26: @@
 }
 </code>
+In this example, the assumption is that ''argv[2]'' holds a string that corresponds to the process name.
 ==== Referencing the languages body ====
@@ Line 34: / Line 34: @@
 lang = p->getlang();
 </code>
+This provides access to all the sub-languages specified within the process.((The refinement body is processed by the expansion phase, and hence the expanded process will contains the appropriate sub-language bodies after taking the specified number of refinement steps into account. This is why ''-ref=k'' is an ACT command-line option.))
 ==== Referencing a particular language body ====
 A language body can be accessed from the languages pointer. For example, for the chp body:
-<code>
+<code c++>
 act_chp *chp;
 chp = lang->getchp();
 </code>
+Note that the ''chp'' pointer will be NULL if there is no CHP sub-language specified within the process definition.
-Finally, to get a pointer to the actual object that stores the chp data structure:
+Finally, to get a pointer to the actual object that stores the CHP data structure:
 <code>
 act_chp_lang_t *chp_lang;
@@ Line 53: / Line 54: @@
 ==== The statement list data structure ====
-The linked list ''list_t'' contains elements of type ''listitem_t''. See ''list.h'' or ''list.c'' for details and available methods. This is used to store lists of statements. To get the actual statement stored in the list of statements, call ''list_value'' on the required ''listitem_t'' of the list:
+The linked list ''list_t'' contains elements of type ''listitem_t''. See ''list.h'' or ''list.c'' for details and available methods. In a CHP data structure, this is used to store lists of statements. To get the actual statement stored in the list of statements, call ''list_value'' on the required ''listitem_t'' of the list:
-<code>
+<code c++>
 act_chp_lang_t *c; // contains the overall chp body
 act_chp_lang_t *stmt;
@@ Line 60: / Line 61: @@
 listitem_t *li;
+// if c->type is ACT_CHP_SEMI or ACT_CHP_COMMA
 stmt_list = c->u.semi_comma.cmd; // returns the linked list