CCom language

Compiler for the CCom (Conditional Comments) language.

Note: This language is part of the Compose Generator project, but also can be used independently.

Introduction

CCom is a language for pre-processing source files. It's primary purpose is to evaluate conditional sections in formats like YAML or XML, but can also be used for a variety of programming languages with support for comments.

Documentation

Please visit the documentation at ccom.compose-generator.com.

Supported data formats

	Line comment iden	Block comment iden open	Block comment iden close
Assembly	;	-	-
C	//	/*	*/
C++	//	/*	*/
Dart	//	/*	*/
Dockerfile	#	-	-
Elixir	#	"""	"""
Go	//	/*	*/
Groovy	//	/*	*/
Haskell	--	-{	-}
HTML	-	<!--	-->
Java	//	/*	*/
JavaScript	//	/*	*/
Julia	#	#=	=#
Kotlin	//	/*	*/
Lua	--	--[[	]]
Pascal	-	(*	*)
Perl	#	=item	=cut
PHP	//	/*	*/
Powershell	#	<#	#>
Python	#	"""	"""
R	#	-	-
Ruby	#	=begin	=end
Rust	//	/*	*/
Spice	//	/*	*/
SQL	--	-	-
Swift	//	/*	*/
TypeScript	//	/*	*/
XML	-	<!--	-->
YAML	#	-	-

Note: Formats like JSON, where no comments are supported can also work with CCom, however then the file input is not valid before pre-processing it with CCom.

Install

Install on Debian / Ubuntu

$ sudo apt-get install ca-certificates
$ curl -fsSL https://server.chillibits.com/files/repo/gpg | sudo apt-key add -
$ sudo add-apt-repository "deb https://repo.chillibits.com/$(lsb_release -is | awk '{print tolower($0)}')-$(lsb_release -cs) $(lsb_release -cs) main"
$ sudo apt-get update
$ sudo apt-get install ccom

Install on Fedora

$ sudo dnf -y install dnf-plugins-core
$ sudo dnf config-manager --add-repo https://server.chillibits.com/files/repo/fedora.repo
$ sudo dnf install ccom

Install on CentOS

$ sudo yum install -y yum-utils
$ sudo yum-config-manager --add-repo https://server.chillibits.com/files/repo/centos.repo
$ sudo yum install ccom

Install on Raspbian

$ sudo apt-get install ca-certificates
$ curl -fsSL https://server.chillibits.com/files/repo/gpg | sudo apt-key add -
$ sudo echo "deb [arch=armhf] https://repo.chillibits.com/$(lsb_release -is | awk '{print tolower($0)}')-$(lsb_release -cs) $(lsb_release -cs) main" > /etc/apt/sources.list.d/chillibits.list
$ sudo apt-get update
$ sudo apt-get install ccom

Install on Windows

CCom gets distributed for Windows via the new Windows package manager called winget. In the future, winget will be available for download in the Microsoft Store. Currently, the easiest way to install winget is, to download it manually from GitHub. Visit the installation instruction from Microsoft.
As soon as the Windows package manager is installed on your Windows machine, you can open powershell and execute this installation command:

$ winget install ChilliBits.CCom

Use with Docker

Linux:

$ docker run --rm -it -v $(pwd):/ccom/out chillibits/ccom

Windows:

$ docker run --rm -it -v ${pwd}:/ccom/out chillibits/ccom

Note: This command does not work with Windows CMD command line. Please use Windows PowerShell instead.

Usage

In general, you call the cli like so:
ccom [options] <input>

CLI options

Option	Shortcut	Description	Default
--benchmark <number>	-b <no>	Execute compiler benchmarks. n is the number of benchmark runs	0
--compiler <name> (temporarily unavailable)	-c <name>	Can be used to switch the compiler backend. Valid inputs are cpp and java	"cpp"
--data <data>	-d <data>	JSON string or path to JSON file, which holds the evaluation work data	{}
--lang <lang>	-l <lang>	File format / programming language (e.g. yaml, java, html, ...)	"auto"*
--mode-single	-m	Set input mode to single statement list	-
--out-file <path>	-o <path>	Path to output file. If you omit this flag, the output will be printed to the console	-
--silent	-s	Only print raw compiler output and no debug output	-
--force	-f	Ignore safety checks. Warning: This could cause demage	-
--line-comment-iden <string>	-lci <string>	Specifies the line comment char(s) of your data format	"#"
--block-comment-iden-open <string>	-bcio <string>	Specifies the opening block comment char(s) of your data format	""
--block-comment-iden-close <string>	-bcic <string>	Specifies the closing block comment char(s) of your data format	""

*) Lang "auto" determines the language based on the file extension of the input file.

Work process

The first thing CCom does, is to analyze the input and determine, whether it is a single condition or a source file. This depends on how you call the CCom CLI. To switch to a single statement, you can call it with the flag --mode-single

Source file mode

CCom takes the whole file and feeds it into the interpreter, starting with the CONTENT grammar node.

Here is an example YAML file, which can be evaluated by CCom:

...
property1: "value1"
#? if has service.angular | has service.mysql {
# property2:
# 	property3: true
#? }
...

Another example for Java with line comments (whatever you want to achieve with that)

public class Example {
	public static void main(String[] args) {
		//? if has property_name | has property
		//? {
		// if () {
		//    System.out.println("True");
		// }
		//? }
		//? if not has property_name {
		// System.out.println("False");
		//? }
	}
}

Another Java example with block comments:

public class Example {
	public static void main(String[] args) {
		/*? if has property_name {
			if () {
				System.out.println("True");
			}
		}*/
		/*? if has property_name {
			if () {
				System.out.println("True");
			}
		}*/
	}
}

Single condition mode (--mode-single)

CCom feeds the condition into the interpreter, starting by the STMT_LST grammar node. The result is either true or false.

Here is an example input:

has service.angular | has service.frontend[1] | has backend

Data file

CCom needs a JSON data tree to work with. To pass a file or a JSON string to CCOM, please use the --data flag.
An example file looks like this:

{
    "version": "0.7.0",
    "service": {
        "frontend": [
            {
                "label": "Spring Maven",
                "name": "spring-maven",
                "dir": "./spring-maven"
            },
            {
                "label": "Spring Gradle",
                "preselected": false
            }
        ],
        "backend": []
    },
    "var": [
        {
            "name": "SPRING_MAVEN_SOURCE_DIRECTORY"
        },
        {
            "name": "SPRING_MAVEN_PACKAGE_NAME",
            "value": "com.chillibits.test-app"
        }
    ]
}

To access 0.7.0, you can use the key version. To access ./spring-maven, you can use the key service.frontend[0].dir.

Grammar

Note a grammar is dependent on the line comment identifiers and the block comment identifiers. In this particular case the line comment char is //, the block comment char open is /* and the block comment char close is */

Start symbol: CONTENT.

CONTENT               --> CHARS (SECTION CHARS)*
SECTION               --> COM_LINE_BLOCK | COM_BLOCK_BLOCK
COM_LINE_BLOCK        --> COM_LINE_IDEN if STMT_LST COM_LINE_IDEN? { PAYLOAD COM_LINE_IDEN }
COM_BLOCK_BLOCK       --> COM_BLOCK_IDEN_OPEN IF_BLOCK COM_BLOCK_IDEN_CLOSE
IF_BLOCK              --> if STMT_LST { PAYLOAD }
COM_LINE_IDEN         --> //?
COM_IDEN_PAYLOAD      --> //
COM_BLOCK_IDEN_OPEN   --> /*?
COM_BLOCK_IDEN_CLOSE  --> */
PAYLOAD               --> (COM_IDEN_PAYLOAD CHARS)+
STMT_LST              --> STMT (`|` STMT)*
STMT                  --> HAS_STMT | COMP_STMT | CONTAINS_STMT
HAS_STMT              --> not? has KEY
COMP_STMT             --> KEY COMP_OP VALUE
CONTAINS_STMT         --> KEY not? contains KEY COMP_OP VALUE
KEY                   --> IDENTIFIER INDEX? (.IDENTIFIER INDEX?)*
INDEX                 --> [NUMBER]
IDENTIFIER            --> (Letter|UNDERSCORE) (LETTER* DIGIT* UNDERSCORE*)*
VALUE                 --> STRING | NUMBER | BOOLEAN
STRING                --> "CHARS_LIMITED"
NUMBER                --> DIGIT+
BOOLEAN               --> true | false
COMP_OP               --> == | != | < | > | <= | >=
CHARS                 --> ({UNICODE}\{COM_LINE_IDEN, COM_BLOCK_IDEN_OPEN})*
CHARS_LIMITED         --> (LETTER* DIGIT* SCHAR* UNDERSCORE*)*
LETTER                --> a|b|...|y|z|A|B|...|Y|Z
DIGIT                 --> 0|1|2|3|4|5|6|7|8|9
SCHAR                 --> -|.|[|]|{|}|/|\|'
UNDERSCORE            --> _
UNICODE               --> Any unicode character

Keywords

• if
• has
• not
• contains

Special characters

• ?
• |
• .
• "
• { / }

AST Classes

Contribute to the project

If you want to contribute to this project, please ensure you comply with the contribution guidelines.

© Marc Auberer 2021-2022