Filed on: {Indigo}<Loops>LoopsCourse>LoopsCourseSummary.bravo
Last edited: GB June 13, 1983 6:43 PM

LOOPS Course Summary

Accessing Objects and Variables

($ name) evaluates to the object or class named name.

($! atom)evaluates to the object or class whose name is the value of atom
(@ accessExpr)evaluates to the value of the instance variable, class variable, or property of these referred to by accessExpr
(@ obj accessExpr)evaluates to the value of the instance variable, class variable, or property of these referred to by accessExpr in obj
(←@ accessExpr newValue)sets the value of the variable accessed by accessExpr to newValue
(←@ obj accessExpr newValue)sets the value of the variable accessed by accessExpr in obj to newValue
accessExpr is the concatenation of any combination of the following with evaluation strictly left to right
:ivNameinstance variable ivName
::cvNameclass variable cvName
:,propNamevalue of property propName
.selectorvalue returned by sending the unary message selector
N.B.a ! (bang) after any of the puctuation in the four lines above will cause the atom following it to be evaluated
and that value to be used as the name
(i.e. ::fee.fie:!foe:,fum will get the value of CV fee of self and send it the message fie, then it will get the instance variable whose name is the value
of foe from the object returned by the message fie, then it will get the value of property fum of that IV)

Defining and Editing Classes

DC(className supersList)(← ($ Class) New className supersList)create a class with name className and supers supersList
EC(className)(← ($ className) Edit)edit the class definition of class className

Defining and Editing Methods

DM(className selector)creates a function with the name className.selector to be used by the method called by selector
DM(className selector fnName)causes the function with the name fnName to be used by the method called by selector
EM(className selector)edit the method used by selector in class className

Creating, Editing, and Inspecting Instances

(← class New)creates a new instance of class
(← class New ’name)creates a new instance of class with the name name
(← obj Edit)(EI obj)edit obj

(← obj Inspect)(INSPECT obj)create an inspect window for obj

(←New class selector arg1 ... argN)create a new instance of class and sends it the the message selector with arguments arg1 ... argN

Sending Messages

(← obj selector arg1 ... argN)send obj the message selector with arguments arg1 ... argN
(←Super obj selector arg1 ... argN)send to the first super of obj which has it defined the message selector with arguments arg1 ... argN
(←! obj expr arg1 ... argN)send obj the message whose selector is the value of expr with the arguments arg1 ... argN

Active Values

#(localState getFn putFn)localState is where the value is stored (this may be another active value)
getFn is the function called on read access and putFn is called on write access

the value returned by getFn in the value of the get operation and putFn has responsibility for changing
the value of localState using the function PutLocalState

Debugging

BreakIt(obj varName)break whenever the instance variable varName of obj is accessed
BreakMethod(className selector)break whenever the method selector is used by any instance of class className
TraceMethod(className selector)trace whenever the method selector is used by any instance of class className
UNBREAK(onlyMostRecentFlg)standard Lisp function to unbreak methods
BreakIt(obj varName propName type breakOnGetAlsoFlg)break whenever the variable varName of obj is accessed (more general)
TraceIt(obj varName propName type breakOnGetAlsoFlg)trace whenever the variable varName of obj is accessed
UnBreakIt(obj varName propName type)remove the break on variable varName of obj
To attach a gauge and monitor a variable:
(←New ($ gaugeType) Attach obj ivName)attaches a gauge of type gaugeType to the instance variable ivName of obj

Rules

↑F gets you into the Rule Executive (OK gets you out of it and UE puts you in the User Executive (where OK will get you back again))
Variables are accesed by using the access expressions as defined above
accessExprgets value of variable (do not use @)
accessExpr←newValuevariable accessed gets newValue
\lispVarNamefor referring to lisp variables use backslash
.selector sends unary message to self (unary message is one that requires no arguments besides self)
DefRSM(className selector)creates a new rule set for the class className invoked by selector and places you in the rule editor

(← ruleSet CopyRules ’newRuleSetName)copies the ruleset ruleSet into a new one called newRuleSetName
(← ruleSet ER)ER(ruleSet)edit ruleSet

ListRuleSets(className)generates a listing of all the rule sets defined for the class className

Browsers

Browse(classList)creates a browser window for the class lattice structure of the classes in classList and their descendants
left or middle button in title area of the browser window updates the lattice structure
Left Mouse Buttongets pop-up menu to print information about class structure and methods
Middle Mouse Buttongets pop-up menu to aid in generating new classes or methods

An asterisk at the end of the name of any item in the menu signifies that there are multiple options for this item
To use the default option, click the left button, for a menu of options click the middle button (i.e. EM* will get a menu with EM and EM!)
To copy from class to class use the left button to "BoxNode" of recepient class then with the middle button menu select the "Move" item with
the middle button to get a menu for either copying of moving of IVs, CVs, Methods, or RuleSets
"Specialize" on the middle button menu will create a new subclass of the one selected and prompt for a name
"DefineMethod" on the middle button menu will create a new method for that class and prompt for its selector

Saving and Restoring Files

(FILES?)Lisp will ask you to assign a filename to each entity it does not already have a file name for
Type yes to specify the file names. For each entity type the filename to save it or ] to not have it saved
LineFeed (LF) means the same as the previous entity
MAKEFILE(filename)saves the file on the file server on the directory currently connected
LOAD(filename)loads the file from the file server on the directory currently connected