--- freem/doc/freem.texi 2025/04/18 15:39:23 1.27 +++ freem/doc/freem.texi 2025/04/18 22:02:33 1.29 @@ -235,15 +235,15 @@ Steve Zeck (Code) $ @command{./freem} [@emph{OPTIONS}...] [[-r ] | [--routine=]] @end example -When FreeM loads, it searches the @code{SYSTEM} namespace for the @code{^%SYSINIT} routine, and begins executing it. +When FreeM loads, it searches the @code{SYSTEM} namespace for the @code{%SYSINIT} routine, and begins executing it. -When @code{-r} or @code{--routine} are passed on the command line, FreeM will load and run the specified routine after running @code{^%SYSINIT}. Beginning with FreeM 0.1.7, routines invoked in this manner are no longer required to perform their own namespace setup with @code{VIEW} commands. +When @code{-r} or @code{--routine} are passed on the command line, FreeM will load and run the specified routine after running @code{%SYSINIT}. Beginning with FreeM 0.1.7, routines invoked in this manner are no longer required to perform their own namespace setup with @code{VIEW} commands. @section %SYSINIT Routine -The @code{^%SYSINIT} routine runs every time a FreeM interpreter process starts. This routine defines some useful constants, enables handling of @code{TRIGGER} events, and handles the execution of code passed via the @code{-x\--execute} or routines passed via @code{-r|--routine}. +The @code{%SYSINIT} routine runs every time a FreeM interpreter process starts. This routine defines some useful constants, enables handling of @code{TRIGGER} events, and handles the execution of code passed via the @code{-x\--execute} or routines passed via @code{-r|--routine}. -Do not modify the supplied @code{^%SYSINIT} routine to add site-specific startup items. Instead, create a @code{^LCLINIT} routine in the @code{USER} namespace of one or more environments. @code{^%SYSINIT} will automatically run @code{^LCLINIT} each time it starts. +Do not modify the supplied @code{%SYSINIT} routine to add site-specific startup items. Instead, create a @code{LCLINIT} routine in the @code{USER} namespace of one or more environments. @code{%SYSINIT} will automatically run @code{LCLINIT} each time it starts. @section Command-Line Options @cindex options, command-line @@ -278,7 +278,7 @@ Allows your M routines to be used as UNI Selects the FreeM namespace to be entered on startup. Must be defined in @file{/etc//freem.conf}. @item @option{-r @emph{}}, @option{--routine=@emph{}} -Causes @code{} to be executed at load, instead of @code{^%SYSINIT}. +Causes @code{} to be executed at load, instead of @code{%SYSINIT}. @item @option{--standard=@emph{}} Sets the default FreeM dialect to use for new routine buffers. @@ -435,10 +435,6 @@ Displays a list of @code{LOCK}s held in @item @command{rbuf} Lists the status of all FreeM routine buffers. -@anchor{dbstats} -@item @command{dbstats} -Shows statistics for the BerkeleyDB global handler. - @anchor{wh} @item @command{wh} Forces an immediate flush of this process's @code{readline} history buffer to disk. @@ -474,7 +470,7 @@ DEFAULT.USER> @end example @item @command{!@emph{}} -Invokes a shell to run @emph{} from within FreeM. This temporarily disables @command{SIGALRM} handling in FreeM, which may interrupt the use of event-driven M programming commands including @command{ESTART} and @command{ESTOP}. +Invokes a shell to run @emph{} from within FreeM. This temporarily disables @command{SIGALRM} handling in FreeM, which may interrupt the use of event-driven M programming commands including @command{ASTART} and @command{ASTOP}. If the @command{>} character is supplied immediately preceding @emph{}, FreeM will append the contents of an M local or global variable referenced in @code{^$JOB($JOB,"PIPE_GLVN")} to the standard input stream of @emph{}. @@ -663,6 +659,8 @@ Please note that FreeM is not entirely s Returns a comma-delimited list of error conditions currently present, and is writable. An empty @code{$ECODE} indicates no errors. +Writing a value in the format @code{,,} into @code{$ECODE} will raise that error condition. + @node $ESTACK @section $ESTACK @cindex $ESTACK @@ -1242,8 +1240,8 @@ The optional fourth argument is the fina Can be used on the left-hand side of an expression in order to @code{@ref{SET}} a value into a @code{d}-delimited piece of @code{s}, as in: @example -; ^jpw="this^is^a^piece" -SET $PIECE(^jpw,"^",2)="isn't" ; => "this^isn't^a^piece" +; ^snw="this^is^a^piece" +SET $PIECE(^snw,"^",2)="isn't" ; => "this^isn't^a^piece" @end example @node $QLENGTH() @@ -1275,7 +1273,7 @@ Returns the number of subscripts in @emp @code{$QSUBSCRIPT(@emph{expr V glvn},@emph{expr V n})} @end example -Returns the @emph{n}th subscript of @emph{glvn}. +In the RHS form, returns the @emph{n}th subscript of @emph{glvn}. @emph{Example} @@ -1283,6 +1281,14 @@ Returns the @emph{n}th subscript of @emp @code{SET SUB=$QSUBSCRIPT("^GBL(1,2,3)",2) ; => 2} @end example +@emph{Syntax} + +@example +@code{SET $QSUBSCRIPT(@emph{expr V glvn},@emph{expr V n})=@emph{expr} ; => ^GBL(1,4,3)} +@end example + +In the LHS form, sets the @emph{n}th subscript of @emph{glvn} to @emph{expr}. + @node $QUERY() @section $QUERY @cindex $QUERY @@ -1300,16 +1306,16 @@ Returns the next subscripted reference i We will assume the following data structure exists: @example -^jpw(1)=1 -^jpw(1,2)="foo" -^jpw(2)=3 -^jpw(3)="" +^snw(1)=1 +^snw(1,2)="foo" +^snw(2)=3 +^snw(3)="" @end example -The following code will retrieve the next subscripted name after @code{^jpw(1)}: +The following code will retrieve the next subscripted name after @code{^snw(1)}: @example -@code{SET NEXTNAM=$QUERY(^jpw(1)) ; => ^jpw(1,2)} +@code{SET NEXTNAM=$QUERY(^snw(1)) ; => ^snw(1,2)} @end example @node $RANDOM() @@ -3300,33 +3306,33 @@ WATCH[@emph{:postcondition}] [+|-|?]@emp @end example -The following example demonstrates turning watchpoint processing on and adding a watchpoint for global variable @code{^jpw(1)}. It then changes the value of @code{^jpw(1)}. +The following example demonstrates turning watchpoint processing on and adding a watchpoint for global variable @code{^snw(1)}. It then changes the value of @code{^snw(1)}. @example DEFAULT.USER> WATCH Watchpoints enabled. -DEFAULT.USER> WATCH +^JPW(1) +DEFAULT.USER> WATCH +^SNW(1) -Added '^JPW("1")' to the watchlist. +Added '^SNW("1")' to the watchlist. -DEFAULT.USER> SET ^JPW(1)="new value" +DEFAULT.USER> SET ^SNW(1)="new value" ->> WATCHPOINT: ^JPW("1") => 'new value' (changed 1 times) +>> WATCHPOINT: ^SNW("1") => 'new value' (changed 1 times) @end example The following example will remove that watchpoint: @example -DEFAULT.USER> WATCH -^JPW(1) +DEFAULT.USER> WATCH -^SNW(1) -Removed '^JPW("1")' from the watchlist. +Removed '^SNW("1")' from the watchlist. -DEFAULT.USER> WATCH ?^JPW(1) +DEFAULT.USER> WATCH ?^SNW(1) -'^JPW("1")' is not being watched. +'^SNW("1")' is not being watched. @end example @node WITH @@ -4166,38 +4172,76 @@ Forces a number to positive, whether pos @section Unary - @cindex operators, unary - +Forces a number to negative, whether positive or negative. Also forces numeric coercion of strings. + @node + @section + (Add) @cindex operators, + +@emph{Syntax} + +@example +S X=1+2 ; => 3 +@end example + +Adds numbers together. + @node += @section += (Add/Assign) @cindex operators, += +@emph{Syntax} + +@example +S X=5 +S X+=3 ; => 8 +@end example + +Increments the variable on the LHS by the value on the RHS. + @node ++ @section ++ (Postfix Increment) @cindex operators, ++ +Increments a variable by 1. + @node - @section - (Subtract) @cindex operators, - +Subtracts one number from another. + @node -= @section -= (Subtract/Assign) @cindex operators, -= +@emph{Syntax} + +@example +S X=5 +S X-=3 ; => 2 +@end example + +Decrements the variable on the LHS by the value on the RHS. + @node -- @section -- (Postfix Decrement) @cindex operators, -- +Decrements the variable by one. + @node * @section * (Multiply) @cindex operators, * +Multiplies one number by another. + @node *= @section *= (Multiply/Assign) @cindex operators, *= + + @node / @section / (Divide) @cindex operators, / @@ -4361,11 +4405,15 @@ An @code{INTEGER} is an interpretation o @cindex data types, REAL @cindex types, REAL +A @code{REAL} is a numeric interpretation of data including a fractional part. + @node STRING @section STRING @cindex data types, STRING @cindex types, STRING +A @code{STRING} is any data in FreeM. + @node Custom Types (Classes) @section Custom Types (Classes) @cindex data types, custom @@ -4438,30 +4486,126 @@ See @ref{Classes}. @cindex programming, object-oriented @menu -* Classes:: The basis of object-oriented programming. +* Classes:: The basis of object-oriented programming. +* Inheritance:: Basing one class upon another. +* Methods:: Attaching code to a class. +* Public and Private Variables:: Managing class member access. @end menu @node Classes @section Classes -@menu -* Inheritance:: Basing one class upon another. -* Methods:: Attaching code to a class. -* Public Variables:: Variables visible outside of a class. -* Private Variables:: Variables only visible within a class. -@end menu +A @emph{class} is the primary organizing concept of FreeM support for object-oriented programming, and in FreeM, is simply an M routine with a few special properties: + +@example +MYCLASS(THIS,INIT):OBJECT ; Constructor for MYCLASS, inherits OBJECT + ; two private variables + S THIS("NUMERATOR"):PRIVATE=$P(INIT,"/",1) + S THIS("DENOMINATOR"):PRIVATE=$P(INIT,"/",2) + Q + ; +DESTROY(THIS) ; This is the destructor + Q +@end example + +The above example demonstrates general class syntax. + +@node Constructors +@subsection Constructors + +A @emph{constructor} is an M entry point that is called when a new instance of a class is created. + +A constructor must be the first entry point in a class routine, its tag must match the class/routine name, and it must take two arguments, @code{THIS} and @code{INIT}. + +@code{THIS} represents the instance of the object being accessed, and @code{INIT} represents an initializer that can be used to assign an initial value to the object when instantiating the class. + +A constructor looks like this: + +@example +%FRACTION(THIS,INIT):OBJECT ; + S THIS("NUMERATOR"):PRIVATE=$P(INIT,"/",1) + S THIS("DENOMINATOR"):PRIVATE=$P(INIT,"/",2) + Q +@end example + +@emph{Syntax} +@example +@emph{}(THIS,INIT)[:@emph{}] +@end example + +In the above example, @emph{} represents the name of a class from which this class should inherit. In this case, the @code{FRACTION} class inherits from the @code{OBJECT} class. Note that this is not strictly necessary in this case, as all classes in FreeM automatically inherit from @code{OBJECT}. + +@node Destructors +@subsection Destructors +A @code{destructor} is called when you @code{KILL} an instance variable. Its tag must be @code{DESTROY}, and it must take one argument (@code{THIS}). + +The destructor should be used to clean up any resources used by class methods. + +A destructor looks like this: + +@example +DESTROY(THIS) ; + ; free any resources that should be freed at the end of the object's lifetime + Q +@end example @node Inheritance -@subsection Inheritance +@section Inheritance + +Every class you create will automatically inherit the methods and functionality of the @code{OBJECT} class, supplied with FreeM. + +When attempting to call a method, FreeM will first search the class routine for a matching entry point, and then follow the inheritance chain upwards until a matching entry point is found. If the final class in the chain does not have a matching entry point, FreeM will try to find a matching entry point in the @code{OBJECT} class. + +Inheritance is achieved by specifying the name of the superclass in the constructor: + +@example +CLASS(THIS,INIT):SUPERCLASS +@end example + +@node Runtime Polymorphism +@subsection Runtime Polymorphism + +You can achieve runtime polymorphism by subclassing, and defining methods in the subclass that match the names of existing methods in the superclass. Following FreeM inheritance rules, the overridden method in the subclass will be called, and the method in the superclass will not. + +Note that the overridden method in the subclass can take a different set or number of arguments than the @emph{formallist} of the superclass method would specify. @node Methods -@subsection Methods +@section Methods +Class methods are defined as tags with @emph{formallist}s in a class routine, and per the typical FreeM object pattern, must take at least one argument, being @code{THIS} (representing a reference to the object instance being accessed). + +The following class (@code{MYCLASS}) has a constructor, a destructor, and a method called @code{MYMETHOD}: + +@example +%MYCLASS(THIS,INIT) ; + Q THIS +DESTROY(THIS) ; + Q +MYMETHOD(THIS) ; + Q "VALUE" +@end example + +@node Public and Private Variables +@section Public and Private Variables + +FreeM supports private fields with the @code{:PRIVATE} specifier in the @code{SET} command, enforcing classical object-oriented data encapsulation. The code{:PUBLIC} specifier is provided for completeness, and is the default. + +The below constructor for a @code{FRACTION} class defines two private fields: -@node Public Variables -@subsection Public Variables +@example +%FRACTION(THIS,INIT):OBJECT ; + S THIS("NUMERATOR"):PRIVATE=$P(INIT,"/",1) + S THIS("DENOMINATOR"):PRIVATE=$P(INIT,"/",2) + Q +@end example + +Either of the following commands will create a public field: + +@example + S THIS("VARNAM")="Initial Value" + S THIS("VARNAM"):PUBLIC="Initial Value" +@end example -@node Private Variables -@subsection Private Variables +Attempting to access private fields from outside of the class will raise error condition @code{ZOBJFLDACCV}. @node Libraries @chapter Libraries @@ -4606,7 +4750,7 @@ TL1:DEFAULT.USER> trantab ------- ------ -------- 1 SET ^FOO=3 2 KILL ^FOO - 3 SET ^jpw=10 + 3 SET ^snw=10 4 SET ^BRANDNEW=6 Global checkpoints: @@ -4614,8 +4758,8 @@ TL1:DEFAULT.USER> trantab GLOBAL MODE FILES ------ ---- ----- ^BRANDNEW CP_REMOVE IN: /usr/local/var/freem/USER/globals/^BRANDNEW - ^jpw CP_RESTORE IN: /usr/local/var/freem/USER/globals/^jpw - OUT: /usr/local/var/freem/USER/globals/^jpw.23390.1.chk + ^snw CP_RESTORE IN: /usr/local/var/freem/USER/globals/^snw + OUT: /usr/local/var/freem/USER/globals/^snw.23390.1.chk ^FOO CP_RESTORE IN: /usr/local/var/freem/USER/globals/^FOO OUT: /usr/local/var/freem/USER/globals/^FOO.23390.1.chk @end verbatim @@ -4834,9 +4978,9 @@ You can also set up a trigger that appli This routine is the implementation of the @code{$ZCOLUMNS} intrinsic special variable. -@section ^%SYSINIT -@cindex ^%SYSINIT -@cindex system library routines, ^%SYSINIT +@section %SYSINIT +@cindex %SYSINIT +@cindex system library routines, %SYSINIT This routine is the default startup routine for FreeM running in direct mode. @@ -6059,7 +6203,7 @@ Module headers should adhere to the foll * binding library * * - * Author: Serena Willis + * Author: Serena Willis * Copyright (C) 1998 MUG Deutschland * Copyright (C) Coherent Logic Development LLC *