From def04721be506f1c7ff5ddf407f2333999570a89 Mon Sep 17 00:00:00 2001 From: Mark Green Date: Fri, 22 Jan 2016 00:54:44 +0000 Subject: Add a try at an Inform 7 tutorial. Obscure, but really interesting. --- inform7.html.markdown | 195 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 195 insertions(+) create mode 100644 inform7.html.markdown (limited to 'inform7.html.markdown') diff --git a/inform7.html.markdown b/inform7.html.markdown new file mode 100644 index 00000000..7f1da0e0 --- /dev/null +++ b/inform7.html.markdown @@ -0,0 +1,195 @@ +--- +language: Inform7 +contributors: + - ["Hyphz", "http://github.com/hyphz/"] +filename: LearnInform.Inform +--- +Inform 7 is a natural language based language created by Graham Nelson and Emily Short for writing text adventures, but also potentially usable for other text based applications, especially data backed ones. + +``` +"LearnInform" by Hyphz + +[This is a comment.] + +[Inform 7 is a language designed for building text adventures. +It can be used for other purposes too, although the default +library builds a text adventure. Inform 7 is object oriented.] + +[This creates a class by subclassing. "Value" is the universal subclass, +but "object" is the most basic that behaves like an OO object.] +A datablock is a kind of object. + +[Classes can have properties.] +A datablock can be broken. [This creates a boolean property.] +A datablock is usually not broken. [This sets its default value.] +A datablock can be big or small. [This creates an enumerated property.] +A datablock is usually small. [This sets its default value.] +A datablock has a number called the sequence number. [This creates a typed property.] +A datablock has some text called the name. ["Some text" means a string.] +A datablock has a datablock called the chain. [Declared classes become types.] + +[This creates a global named instance.] +Block1 is a datablock. +The sequence number of Block1 is 1. +The name of Block1 is "Block One." + +[Functions and procedures are defined as "phrases".] +To do the thing everyone does with their first program: + say "Hello World.". [Full stop indicates the end, indent indicates the scope.] + +To dump (the block - a datablock): [That's how we create a parameter.] + say the sequence number of the block; + say the name of the block; + if the block is broken, say "(Broken)". + +To toggle (the block - a datablock): + if the block is broken: [Conditional.] + now the block is not broken; [Updating a property.] + else: + now the block is broken. + +[Multiple parameters.] +To fix (the broken block - a datablock) using (the repair block - a datablock): + if the broken block is not broken, stop; [Comma for a non indented single command.] + if the repair block is broken, stop; + now the sequence number of the broken block is the sequence number of the repair block; + now the broken block is not broken. + +[Because of its text adventure origins, Inform 7 doesn't generally allow objects +to be created dynamically, although there's a language extension that enables it.] +Block2 is a datablock. +Block2 is broken. +The sequence number of Block2 is 2. +The name of Block2 is "Block two." + +To demonstrate calling a phrase with two parameters: + Let the second block be block2; [Local pointer variable.] + fix the second block using Block1; + say the sequence number of the second block. [1.] + +[Lists.] +To show how to use list types: + let the list be a list of datablocks; + add Block1 to the list; + add Block2 to the list; + say the list; ["Block1 and Block2"] + [Membership.] + if Block1 is listed in the list: + say "Block1 is there."; + [Loop.] + repeat with the block running through the list: + dump the block; [1 Block One. 1 Block Two.] + [Remember block two's sequence number was changed above.] + let X be entry 2 of the list; [Counting starts at 1.] + dump X; ["1 Block two."] + remove X from the list; + say the list. [Block1] + +[Here's how we define a function and do arithmetic.] + +To decide which number is the sum of all numbers up to (X - a number) (this is summing up): + let the total so far be a number; + repeat with the current number running from 1 to X: + now the total so far is the total so far + the current number; + decide on the total so far. [This is the return statement.] + +[ We have higher order functions too. ] + +To demonstrate a higher order function: + say summing up applied to {1, 2, 3, 4}. + +To decide which number is the result of applying (phrase - phrase A -> A) twice to (B - a value of kind A): + let b1 be phrase applied to B; + let b2 be phrase applied to b1; + decide on b2. + +To demonstrate defining a higher order function: + let X be 5; + say the result of applying summing up twice to X. + +[ Rulebooks allow a number of functions which apply to the same type under different conditions to be stacked. ] + +Datablock validation rules is a datablock based rulebook. + +A datablock validation rule for a broken datablock: rule fails. +A datablock validation rule for a datablock (called the block): + dump the block; + rule succeeds. + +To demonstrate invoking a rulebook: + follow datablock validation rules for Block1; + follow datablock validation rules for Block2. + +[ Objects can also have relations, which resemble those in a relational database. ] +A dog is a kind of thing. +Rover is a dog. +The kennel is a container. [This is a built in base class.] +Rover is in the kennel. [This creates an inbuilt relation called "containment".] + +[We can create relations by declaring their type.] + +Guide dog ownership relates one dog to one person. [One-to-one.] +Property ownership relates various things to one person. [Many-to-one.] +Friendship relates various people to various people. [Many-to-many.] + +[To actually use them we must assign verbs or prepositions to them.] + +The verb to own means the property ownership relation. +The verb to be the guide dog of means the guide dog ownership relation. +The verb to be guided by means the reversed guide dog ownership relation. +The verb to be friends with means the friendship relation. + +Edward is a person. A person can be blind. Edward is blind. +Edward is guided by Rover. +Benny is a person. Edward is friends with Benny. + +To demonstrate looking something up with a relation: + repeat with the dog running through things that are the guide dog of Edward: + say the dog; + repeat with the friend running through things that are friends with Edward: + say the friend. + +[We can also define relations that exist procedurally.] + +Helpfulness relates a person (called the helper) to a person (called the helpee) when the helpee is blind and the helper is not blind. +The verb to be helpful to means the helpfulness relation. +To demonstrate using a procedural relation: + repeat with the helper running through people that are helpful to Edward: + say the helper. + + +[ Interface to the text adventure harness to allow the above code to be run. ] +Tutorial room is a room. +"A rather strange room full of buttons. Push them to run the exercises, or turn on the robot to run them all." +A button is a kind of thing. A button is fixed in place. + +The red button is a button in tutorial room. +Instead of pushing the red button, do the thing everyone does with their first program. +The green button is a button in tutorial room. +Instead of pushing the green button, demonstrate calling a phrase with two parameters. +The blue button is a button in tutorial room. +Instead of pushing the blue button, show how to use list types. +The cyan button is a button in tutorial room. +Instead of pushing the cyan button, say the sum of all numbers up to 5. +The purple button is a button in tutorial room. +Instead of pushing the purple button, demonstrate a higher order function. +The black button is a button in tutorial room. +Instead of pushing the black button, demonstrate defining a higher order function. +The white button is a button in tutorial room. +Instead of pushing the white button, demonstrate invoking a rulebook. +The puce button is a button in tutorial room. +Instead of pushing the puce button, demonstrate looking something up with a relation. +The orange button is a button in tutorial room. +Instead of pushing the orange button, demonstrate using a procedural relation. + +The robot is an object in tutorial room. +Instead of switching on the robot: + say "The robot begins to frantically flail its arms about."; + repeat with button running through buttons in the tutorial room: + say "The robot randomly hits [the button]."; + try pushing button. +``` + +##Ready For More? + +* [Inform 7](http://www.inform7.com/) -- cgit v1.2.3