Hello In the thread 'including Pillar in Pharo image by default' it was suggested by Stephane Ducasse to include a subset of Pillar in the Pharo image[1] .
I'd like to extend that proposal a little bit it in order to do very simple presentations. This should allow to describe at least part of the slides used in the MOOC course [3]. This will be _a possible_ solution to the question brought up in the thread 'Writing "powerpoint" like presentations in Pharo?'. Another use is to write instructions with executable content within the image ("Assistants"). So below is the a proposal for a Pillar syntax _subset_ for class comments and _simple_ presentations. The numbering scheme follows the 'Pillar syntax cheat sheet' [2] MINI PILLAR SYNTAX (a subset of Pillar) 1. Headers !Header 1 !!Header 2 !!!Header 3 2. Lists - Unordered List # Ordered list 5. Emphasis ""bold"" 6. Code blocks [[[ Transcript show: 'Hello World'. \]]] 9. Annotation ${slide:title=About Pharo}$ Next week I plan to implement the rendering of this 'Mini Pillar' in Morphic using the Morphic API subset that works in Pharo and Squeak. A renderer using Bloc would also be nice. [4] Comments, suggestions, code snippets and other help is welcome. Regards Hannes -------------------------------------------------------------------------------------------------- [1] Pillar subset for class comments Stephane Ducasse <stepharo.s...@gmail.com> Fri, Aug 11, 2017 at 7:09 PM To: Any question about pharo is welcome <pharo-users@lists.pharo.org> Tx cyril For class comment I image that we want ! - - *url* and bold [[[ ]]] Did I miss something. Stef -------------------------------------------------------------------------------------------------- [2] http://pillarhub.pharocloud.com/hub/pillarhub/pillarcheatsheet -------------------------------------------------------------------------------------------------- 1. Headers !Header 1 !!Header 2 !!!Header 3 !!!!Header 4 !!!!!Header 5 !!!!!!Header 6 2. Lists - Unordered List # Ordered list 3. Table |! Left |! Right |! Centered |{Left |}Right| Centered 4. Description Note on a new line ;head :item 5. Emphasis ""bold"" ''italic'' --strikethrough-- __underscore__ ==inline code== @@subscript@@ ^^sub-script^^ 6. Code blocks [[[label=helloScript|caption=How to print Hello World|language=Smalltalk Transcript show: 'Hello World'. \]]] 7. Raw {{{latex: this is how you inject raw \LaTeX in your output file }}} {{{markdown: this is how you inject raw `markdown` in your output file }}} {{{html: this is how you inject raw <b>html</b> in your output file }}} 8. Links Anchor @anchor (new line) Internal link *anchor* External link *Google>http://google.com* Image +Caption>file://image.png|width=50|label=label+ 9. Annotation Note on a new line Annotation @@note this is a note Todo item @@todo this is to do 10. Comments % each line starting with % is commented 11. References This document is copied from http://www.cheatography.com/benjaminvanryseghem/cheat-sheets/pillar/ ---------------------------------------------------------------------- [3] Example pillar code for slides ---------------------------------------------------------------------- https://github.com/SquareBracketAssociates/PharoMooc/blob/master/Slides/1-Templates/SlideExample.pillar { "title":"To the Roots of Objects", "subtitle":"Learning from beauty", "author":"Stephane Ducasse", "complement":"http://stephane.ducasse.free.fr/ \\\\ stephane.duca...@inria.fr" } ${toc:depthLevel=2|level=0|highlight=0}$ %Les sections ne sont pas des titres de slide mais définnissent la structure du doucment. Il est possible de rajouter "renderStructureAsSlide":false dans pillar.conf pour ne pas créer de slide à partir d'un titre. ${slide:title=License}$ +>file://figures/CreativeCommons.png|width=50|label=figCreativeCommons+ ! Introduction % ${toc:depthLevel=1|level=0|highlight=1}$ ${slide:title=Really?!|label=really}$ ${columns}$ ${column:width=50}$ %the width parameter take an Int between 1 and 100 %For now we have to pass a line before and after an annotation, I'll correct that soon in Pillar. - No primitive types - No hardcoded constructs for conditional - Only messages - Only objects ${column:width=50}$ - and this works? - I mean really? - Not even slow? - Can't be real! ${endColumns}$ ${slide:title=Motto}$ - Let's open our eyes, look, understand, and deeply understand the underlying design aspects of object-oriented programming. *@really* *TEST !>@really* ${slide:title=Booleans}$ [[[language=smalltalk 3 > 0 ifTrue: ['positive'] ifFalse: ['negative'] -> 'positive' ]]] ${slide:title=Yes ifTrue\:ifFalse\: is a message!}$ [[[language=smalltalk Weather isRaining ifTrue: [self takeMyUmbrella] ifFalse: [self takeMySunglasses] ]]] - Conceptually ==ifTrue:ifFalse:== is a message sent to an object: a boolean! - ==ifTrue:ifFalse:== is in fact radically optimized by the compiler but you can implement another one such ==siAlors:sinon:== and check. ${slide:title=Booleans}$ In Pharo booleans have nothing special - & | not - or: and: (lazy) - xor: - ifTrue:ifFalse: - ifFalse:ifTrue: - ... ${slide:title=Lazy Logical Operators}$ *LINK>@frm:really* [[[language=smalltalk false and: [1 error: 'crazy'] -> false and not an error ]]] ! Exercices ${toc:depthLevel=1|level=0|highlight=1}$ !! Exercise 1: Implement not ${slide:title=Exercise 1\: Implement not}$ - Propose an implementation of not in a world where you do not have Booleans. - You only have objects and messages. [[[language=smalltalk false not -> true true not -> false ]]] !!Exercise 2: Implement | (Or) ifTrue: ifFalse: ${toc:depthLevel=2|level=0|highlight=1}$ ${slide:title=Exercise 2\: Implement \| (Or)}$ - Propose an implementation of or in a world where you do not have Booleans. - You only have objects and messages. [[[language=smalltalk true | true -> true true | false -> true true | anything -> true false | true -> true false | false -> false false | anything -> anything ]]] ${slide:title=Exercise2\: Variation - Implement ifTrue\:ifFalse\:}$ - Propose an implementation of not in a world where you do not have Booleans. - You only have objects, messages and closures. [[[language=smalltalk false ifTrue: [ 3 ] ifFalse: [ 5 ] -> 5 true ifTrue: [ 3 ] ifFalse: [ 5 ] -> 3 ]]] ! Boolean Implementation ${toc:depthLevel=1|level=0|highlight=1}$ ${slide:title=Booleans Implementation Hint One}$ - The solution does not use conditionals - else we would obtain a recursive definition of ==ifTrue:ifFalse:== ${slide:title=Boolean Implementation Hint Two}$ - The solution uses three classes: ==Boolean==, ==True== and ==False== - ==false== and ==true== are unique instances described by their own classes - ==false== is an instance of the class ==False== - ==true== is an instance of the class ==True== +Boolean Hierarchy>file://figures/BooleanHiearchyAndInstances.png|width=50+ ${slide:title=How do we express choice in OOP?}$ - We send messages to objects [[[language=smalltalk aButton color -> Color red aPane color -> Color blue aWindow color -> Color grey ]]] - Let's the receiver decide - Do not ask, tell ${slide:title=Boolean not implementation}$ - Class ==Boolean== is an abstract class that implements behavior common to true and false. Its subclasses are ==True== and ==False==. Subclasses must implement methods for logical operations ==&==, ==not==, and controls ==and:==, ==or:==, ==ifTrue:==, ==ifFalse:==, ==ifTrue:ifFalse:==, ==ifFalse:ifTrue:== [[[language=smalltalk Boolean>>not "Negation. Answer true if the receiver is false, answer false if the receiver is true." self subclassResponsibility ]]] ${slide:title=Not implementation in two methods}$ [[[language=smalltalk False>>not "Negation -- answer true since the receiver is false." ^ true ]]] [[[language=smalltalk True>>not "Negation--answer false since the receiver is true." ^ false ]]] ${slide:title=Not implementation in two methods}$ +Not implementation.>file://figures/BooleanHiearchyAndInstancesWithNotMethods.png|width=80+ ${slide:title=\| (Or)}$ [[[language=smalltalk true | true -> true true | false -> true true | anything -> true false | true -> true false | false -> false false | anything -> anything ]]] ${slide:title=Boolean>> \| aBoolean}$ [[[language=smalltalk Boolean>> | aBoolean "Evaluating disjunction (OR). Evaluate the argument. Answer true if either the receiver or the argument is true." self subclassResponsibility ]]] ${slide:title=False>> \| aBoolean}$ [[[language=smalltalk false | true -> true false | false -> false false | anything -> anything ]]] [[[language=smalltalk False >> | aBoolean "Evaluating disjunction (OR) -- answer with the argument, aBoolean." ^ aBoolean ]]] ${slide:title=True>> \| aBoolean}$ [[[language=smalltalk true | true -> true true | false -> true true | anything -> true ]]] [[[language=smalltalk True>> | aBoolean "Evaluating disjunction (OR) -- answer true since the receiver is true." ^ self ]]] ${slide:title=Or implementation in two methods}$ +>file://figures/BooleanHiearchyAndInstancesWithOrMethods.png|width=80+ ${slide:title=Implementing ifTrue\:ifFalse\:}$ - Do you see the pattern? - Remember that a closure freezes execution and that value launches the execution of a frozen code. [[[language=smalltalk True>>ifTrue: aTrueBlock ifFalse: aFalseBlock ^ aTrueBlock value ]]] [[[language=smalltalk False>>ifTrue: aTrueBlock ifFalse: aFalseBlock ^ aFalseBlock value ]]] ${slide:title=Implementation Note}$ - Note that the Virtual Machine shortcuts calls to boolean such as condition for speed reason. - But you can implement your own conditional method and debug to see that sending a message is dispatching to the right object. ! So what ? ${toc:depthLevel=1|level=0|highlight=1}$ ${slide:title=Ok so what?}$ - You will probably not implement another Boolean classes - So is it really that totally useless? ${slide:title=Message sends act as case statements}$ - The execution engine will select the right method in the class of the receiver - The case statements is dynamic in the sense that it depends on the classes loaded and the objects to which the message is sent. - Each time you send a message, the system will select the method corresponding to the receiver. ${slide:title=A Class Hierarchy is a Skeleton for Dynamic Dispatch}$ - If we would have said that the ==Boolean== would be composed of only one class, we could not have use dynamic binding. - A class hierarchy is the exoskeleton for dynamic binding - Compare the solution with one class vs. a hierarchy. +One single class vs. a nice hierarchy.>file://figures/Design-FatVsDispatch.png|width=70+ - The hierarchy provides a way to specialize behavior. - It is also more declarative in the sense that you only focus on one class. - It is more modular in the sense that you can package different classes in different packages. ${slide:title=Avoid Conditionals}$ - Use objects and messages, when you can - The execution engine acts as a conditional switch: Use it! - Check the AntiIfCampaign. ${slide:title=Follow-up: Implement ternary logic}$ - Boolean: ==true==, ==false==, ==unknown== +Ternaru Logic decision table >file://figures/ArrayBoolean.png|width=30|label=fig:ternLogic+ - Implementing in your own classes. ! Summary ${toc:depthLevel=1|level=0|highlight=1}$ ${slide:title=Summary}$ - Tell, do not ask - Let the receiver decide - Message sends as potential dynamic conditional - Class hiearchy builds a skeleton for dynamic dispatch - Avoid conditional ----------------------------------------- [4] Bloc Load Bloc with executing in a playground (Pharo 6.1) Metacello new baseline: 'Bloc'; repository: 'github://pharo-graphics/Bloc:pharo6.1/src'; load: #core A tutorial to use bloc is available on http://files.pharo.org/books/ Bloc Memory Game (alpha) is a first tutorial on Bloc the new graphics core for Pharo. Booklet written by A. Chis, S. Ducasse, A. Syrel. http://files.pharo.org/books-pdfs/booklet-Bloc/2017-11-09-memorygame.pdf To load the memory game Metacello new baseline: 'BlocTutorials'; repository: 'github://pharo-graphics/Tutorials/src'; load A similar booklet could be done for the title 'Doing a presentation / slide show / assitant with Bloc' (or similar, adapt .....)