[README] Added a more detailed definition of the language with many examples

1 files changed, 347 insertions, 56 deletions

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 # csma
 
+csma is a tiny superset of CSS, with the goal of making rules more organizeable and modular than ever.
 
+## How to use
 
-## Getting started
+Currently the only preprocessor is "preproc.awk":
 
-To make it easy for you to get started with GitLab, here's a list of recommended next steps.
+```bash
+awk -f preproc.awk styles.csma styles.csma
+```
+
+Remember to pass the csma file **twice**
+
+## Language reference
+
+The syntactical additions to CSS are two:
+
+- macro name
+- macro definition
+
+The concept is inspired from C-like macros.
+There is no **CSS modification**, you can only really move around rules (and text).
+
+### (Standalone) Macro name
+
+A macro name is a string in the form:
+
+```
+<LETTERS>
+```
+
+where LETTERS can be any combination and length of letters, excluding `>`, `&` and newlines.
+
+A macro name can be placed almost anywhere in a CSS file and it will be replaced by some value.
+
+### Macro definition
+
+That value is specified via macro definitions, a macro name followed by curly braces:
+
+```
+<NAME> {
+    VALUE
+}
+```
+
+Now, every time you have a standalone `<NAME>`, it will be replaced with `VALUE`.
+The curly brace can be anywhere after the macro name, even after multiple new lines, but there must only be blank characters between them.
+
+Let's look at an example:
+
+```
+<Number>
+<Number> { 5 }
+```
+
+The resulting file will be:
+
+```
+5
+```
+
+As you can see, the definitions are parsed before (standalone) macro names, so it doesn't matter if the standalone name is before or after the definition.
+
+Multiple definitions with the same macro name are concatenated, so with:
+
+```
+<Number>
+<Number> { 5 }
+<Number> { 6 }
+```
+
+you'll get:
+
+```
+56
+```
+
+Newlines inner empty lines are preserved, so this:
+
+```
+<Number>
+<Number> {
+
+  5
+
+}
+<Number> {
+  6
+
+}
+```
+
+results into:
+
+```
+
+5
+
+6
+
+```
+
+### Inner macro definitions
+
+You are also allowed to put definitions inside other definitions:
+
+```
+<Color> {
+  <Text> { black }
+  <Body> { white }
+}
+```
+
+#### Nested macro's name
+
+Inner definitions come with a trick: their name is accessed by prepending their parent and "/".
+So, this **won't** result in anyting:
+
+```
+<Color> {
+  <Text> { black }
+  <Body> { white }
+}
+<Text>
+```
+
+however this **will** result in the word "black":
+
+```
+<Color> {
+  <Text> { black }
+  <Body> { white }
+}
+<Colors/Text>
+```
+
+It's important to note that this changes the **entire name** of the macro and every macro is globally accessible.
+There is no actual tree-like structure behind it, so the syntax:
+
+```
+<A> {
+  <B1> { ... }
+  <B2> { ... }
+  ...
+  <BN> { ... }
+}
+```
+
+is (almost) equivalent to:
+
+```
+<A> {
+}
+<A/B1> { ... }
+<A/B2> { ... }
+...
+<A/BN> { ... }
+```
+
+You can nest as much as you like, and for every paren't you get another "name/" prepended, in this:
+
+```
+<A> {
+  <B> {
+    <C> {
+      89
+    }
+  }
+}
+```
+
+you have three macros: `<A>`, `<A/B>` and `<A/B/C>`.
+
+#### Nested macro replacement
+
+Nested macro definitions are also automatically replaced in their parent.
+So here:
+
+```
+<A> {
+  rule1
+  <B> {
+    rule2
+  }
+}
+
+<A>
+
+<A/B>
+```
+
+you'll get:
+
+```
+
+rule1
+rule2
+
+rule2
+```
+
+So nested definitions:
+
+```
+<A> {
+  <B1> { ... }
+  <B2> { ... }
+  ...
+  <BN> { ... }
+}
+```
 
-Already a pro? Just edit this README.md and make it your own. Want to make it easy? [Use the template at the bottom](#editing-this-readme)!
+are "spiritually" equivalent to:
 
-## Add your files
+```
+<A> {
+  <B1>
+  <B1> { ... }
+  <B2>
+  <B2> { ... }
+  ...
+  <BN>
+  <BN> { ... }
+}
+```
 
-- [ ] [Create](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#create-a-file) or [upload](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#upload-a-file) files
-- [ ] [Add files using the command line](https://docs.gitlab.com/ee/gitlab-basics/add-file.html#add-a-file-using-the-command-line) or push an existing Git repository with the following command:
+But **only when actually nested!**
+So if we rewrite the example from above like:
 
 ```
-cd existing_repo
-git remote add origin https://gitlab.com/Syndamia/csma.git
-git branch -M main
-git push -uf origin main
+<A> {
+  rule1
+}
+<A/B> {
+  rule2
+}
+
+<A>
+
+<A/B>
 ```
 
-## Integrate with your tools
+the result will be:
 
-- [ ] [Set up project integrations](https://gitlab.com/Syndamia/csma/-/settings/integrations)
+```
 
-## Collaborate with your team
+rule1
 
-- [ ] [Invite team members and collaborators](https://docs.gitlab.com/ee/user/project/members/)
-- [ ] [Create a new merge request](https://docs.gitlab.com/ee/user/project/merge_requests/creating_merge_requests.html)
-- [ ] [Automatically close issues from merge requests](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html#closing-issues-automatically)
-- [ ] [Enable merge request approvals](https://docs.gitlab.com/ee/user/project/merge_requests/approvals/)
-- [ ] [Set auto-merge](https://docs.gitlab.com/ee/user/project/merge_requests/merge_when_pipeline_succeeds.html)
+rule2
+```
 
-## Test and Deploy
+#### Nested macro concatenation
 
-Use the built-in continuous integration in GitLab.
+Since multiple definitions are concatenated, there is no problem in doing:
 
-- [ ] [Get started with GitLab CI/CD](https://docs.gitlab.com/ee/ci/quick_start/index.html)
-- [ ] [Analyze your code for known vulnerabilities with Static Application Security Testing (SAST)](https://docs.gitlab.com/ee/user/application_security/sast/)
-- [ ] [Deploy to Kubernetes, Amazon EC2, or Amazon ECS using Auto Deploy](https://docs.gitlab.com/ee/topics/autodevops/requirements.html)
-- [ ] [Use pull-based deployments for improved Kubernetes management](https://docs.gitlab.com/ee/user/clusters/agent/)
-- [ ] [Set up protected environments](https://docs.gitlab.com/ee/ci/environments/protected_environments.html)
+```
+<A/B>
+<A> {
+  <B> {}
+}
+<A/B> { 1 }
+<A> {
+  <B> { 5 }
+}
+```
 
-***
+the result will be:
 
-# Editing this README
+```
+15
+```
 
-When you're ready to make this README your own, just edit this file and use the handy template below (or feel free to structure it however you want - this is just a starting point!). Thanks to [makeareadme.com](https://www.makeareadme.com/) for this template.
+### Inner standalone macro names
 
-## Suggestions for a good README
+Replacement of standalone macro names also happens inside definitions.
+This:
 
-Every project is different, so consider which of these sections apply to yours. The sections used in the template are suggestions for most open source projects. Also keep in mind that while a README can be too long and detailed, too long is better than too short. If you think your README is too long, consider utilizing another form of documentation rather than cutting out information.
+```
+<A>
+<A> {
+  <B>
+}
+<B> {
+  rule
+}
+```
 
-## Name
-Choose a self-explaining name for your project.
+results into:
 
-## Description
-Let people know what your project can do specifically. Provide context and add a link to any reference visitors might be unfamiliar with. A list of Features or a Background subsection can also be added here. If there are alternatives to your project, this is a good place to list differentiating factors.
+```
+rule
+```
 
-## Badges
-On some READMEs, you may see small images that convey metadata, such as whether or not all the tests are passing for the project. You can use Shields to add some to your README. Many services also have instructions for adding a badge.
+This also allows us to kinda do the nested macro replacement without actually nesting the entire macro definition:
 
-## Visuals
-Depending on what you are making, it can be a good idea to include screenshots or even a video (you'll frequently see GIFs rather than actual videos). Tools like ttygif can help, but check out Asciinema for a more sophisticated method.
+```
+<A> {
+  rule1
+  <A/B>
+}
+<A/B> {
+  rule2
+}
 
-## Installation
-Within a particular ecosystem, there may be a common way of installing things, such as using Yarn, NuGet, or Homebrew. However, consider the possibility that whoever is reading your README is a novice and would like more guidance. Listing specific steps helps remove ambiguity and gets people to using your project as quickly as possible. If it only runs in a specific context like a particular programming language version or operating system or has dependencies that have to be installed manually, also add a Requirements subsection.
+<A>
 
-## Usage
-Use examples liberally, and show the expected output if you can. It's helpful to have inline the smallest example of usage that you can demonstrate, while providing links to more sophisticated examples if they are too long to reasonably include in the README.
+<A/B>
+```
+
+the result is:
+
+```
 
-## Support
-Tell people where they can go to for help. It can be any combination of an issue tracker, a chat room, an email address, etc.
+rule1
+rule2
 
-## Roadmap
-If you have ideas for releases in the future, it is a good idea to list them in the README.
+rule2
+```
+
+## How to use effectively in CSS
 
-## Contributing
-State if you are open to contributions and what your requirements are for accepting them.
+Image the following scenario, you have a website with:
 
-For people who want to make changes to your project, it's helpful to have some documentation on how to get started. Perhaps there is a script that they should run or some environment variables that they need to set. Make these steps explicit. These instructions could also be useful to your future self.
+- header with website logo, links to pages and a hidden menu bar, for mobile devices
+- page with text and picture contents
+- image reel
+- footer with social links, a map with your business address and disclaimers
 
-You can also document commands to lint the code or run tests. These steps help to ensure high code quality and reduce the likelihood that the changes inadvertently break something. Having instructions for running tests is especially helpful if it requires external setup, such as starting a Selenium server for testing in a browser.
+The CSS rules can stack up very quickly, and it can be difficult to maintain.
+One way in which you can use CSMA is by representing your site structure with different macros and dividing everything into them:
+
+```
+<Page>
 
-## Authors and acknowledgment
-Show your appreciation to those who have contributed to the project.
+<Page> {
+  body { ... }
+
+  <Page/Header>
+  <Page/Contents>
+  <Page/Footer>
+}
+
+<Page/Header> {
+  header { ... }
+
+  <Link> {
+    .header-link {
+      ...
+    }
+    .header-link:hover() {
+      ...
+    }
+  }
+
+  <Logo> {
+    .header-logo {
+      ...
+    }
+  }
+}
+
+<Page/Contents> {
+  article {
+    ...
+  }
+  <Image reel>
+  a {
+    ...
+  }
+  b {
+    ...
+  }
+}
+
+<Page/Footer> {
+  ...
+}
+```
 
-## License
-For open source projects, say how it is licensed.
+But this is just an example.
 
-## Project status
-If you have run out of energy or time for your project, put a note at the top of the README saying that development has slowed down or stopped completely. Someone may choose to fork your project or volunteer to step in as a maintainer or owner, allowing your project to keep going. You can also make an explicit request for maintainers.
+You may want to have even more macros that mostly contain other macros (like with `<Page>`).
+This way you can very easily turn on or off a feature, and rules are easily discoverable (for example, try finding the rule for the header logo).