news.shamcode.ru | yoav-lavi / melody

yoav-lavi / melody

суббота, 19 февраля 2022 г. в 00:29:59

Melody is a language that compiles to regular expressions and aims to be more easily readable and maintainable

Melody is a language designed to compile to and maintain a 1-1 relationship with regular expressions, while being more readable and maintainable.

The current goal is supporting the JavaScript implementation of regular expressions.

⚠️ Melody is very new and is unstable at the moment ⚠️

Examples

Note: these are for the currently supported syntax and may change

Batman Theme

16 of "na";

2 of match {
  <space>;
  "batman";
}

// 🦇🦸‍♂️

Turns into

/(?:na){16}(?:\sbatman){2}/

Twitter Hashtag

"#";
some of <word>;

// #melody

Turns into

/#\w+/

Introductory Courses

some of <word>;
<space>;
"1";
2 of <digit>;

// classname 1xx

Turns into

/\w+\s1\d{2}/

Indented Code (2 spaces)

some of match {
  2 of <space>;
}

some of char;
";";

//  let value = 5;

Turns into

/(?:\s{2})+.+;/

Install

From Source

git clone https://github.com/yoav-lavi/melody.git
cd melody
cargo install --path .

CLI Usage

melody [OPTIONS] <PATH>

OPTIONS:
  -f, --file <FILE>    write to an output file
  -n, --no-color       print output with no color
  -V, --version        print version information
  -h, --help           print help information

Keywords

of - used after a number or a range and before a sequence to be matched, e.g. 5 of "A";, equivalent to regex {5}
to - used to create a range (either as a quantifier or as a character range), e.g. 5 to 9, equivalent to regex {5,9} if before an of or [5-9] otherwise
capture - used to open a capture or named capture block, equivalent to regex (...)
match - used to open a match block, equivalent to regex (?:...)
start - matches the start of the string, equivalent to regex ^
end - matches the end of the string, equivalent to regex $
char - matches a single character, equivalent to regex .
some - used with of to express 1 or more of a pattern, equivalent to regex +
over - used with of to express more than an amount of a pattern, equivalent to regex {6,} (assuming over 5 of ...)

Symbols

<space> - equivalent to regex \s
<newline> - equivalent to regex \n
<tab> - equivalent to regex \t
<return> - equivalent to regex \r
<feed> - equivalent to regex \f
<null> - equivalent to regex \0
<digit> - equivalent to regex \d
<vertical> - equivalent to regex \v
<word> - equivalent to regex \w

Concepts

"..." or '...' - used to mark a literal part of the match

Extras

// - used to mark comments

File Extension

The Melody file extension is .mdy

Syntax Highlighting

VSCode

Get the extension here

Feature Status

✅ - Implemented

🐣 - Partially implemented

❌ - Not implemented

❓ - Unclear whether this will be implemented

❔ - Unclear what the syntax will be

Melody	Regex	Status
`5 of "hello";`	`(?:hello){5}`	✅
`5 to 7 of "A";`	`A{5,7}`	✅
`capture { ... }`	`(...)`	✅
`capture name { ... }`	`(?<name>...)`	✅
`match { ... }`	`(?:...)`	✅
`<space>;`	`\s`	✅
`A to Z;`	`[A-Z]`	✅
`a to z;`	`[a-z]`	✅
`0 to 9;`	`[0-9]`	✅
`// comment`		✅
`start;`	`^`	✅
`end;`	`$`	✅
`<newline>;`	`\n`	✅
`<tab>;`	`\t`	✅
`<return>;`	`\r`	✅
`<feed>;`	`\f`	✅
`<null>;`	`\0`	✅
`<digit>;`	`\d`	✅
`<vertical>;`	`\v`	✅
`<word>;`	`\w`	✅
`"...";` (raw)	...	✅
`'...';` (raw)	...	✅
`'\'';`	`'`	✅
`"\"";`	`"`	✅
support non alphanumeric characters		✅
output to file		✅
no color output		✅
`char`	`.`	✅
`some of`	`+`	✅
syntax highlighting extension		✅
`over 5 of "A";`	`A{6,}`	✅
enforce group close		🐣
tests		🐣
`not <space>;`	`\S`	❌
`not <digit>;`	`\D`	❌
`not <word>;`	`\W`	❌
`<backspace>`	`[\b]`	❌
file watcher		❌
nested groups	`(...(...))`	❌
multiple ranges	`[a-zA-Z0-9]`	❌
general cleanup and modules		❌
auto escape for non Melody patterns		❌
rust library / macro		❌
TS/JS build step		❌
more robust parsing mechanism (ast)		❌
`not "A";`	`[^A]`	❔
`flags: global, multiline, ...`	`/.../gm...`	❔
`/* comment */`		❔
`maybe of`	`?`	❔
`maybe some of`	`*`	❔
`either of ..., ...`	`\|`	❔
`any of "a", "b", "c"`	`[abc]`	❔
`... not before ...`	`...(?!...)`	❔
`... not after ...`	`...(?<!...)`	❔
`... before ...`	`...(?=...)`	❔
`... after ...`	`...(?<=...)`	❔
(?)	`*?`	❔
(?)	`\#`	❔
(?)	`\k<name>`	❔
(?)	`\p{...}`	❔
(?)	`\P{...}`	❔
(?)	`\uYYYY`	❔
(?)	`\xYY`	❔
(?)	`\ddd`	❔
(?)	`\cY`	❔
(?)	`\b`	❔
(?)	`\B`	❔
(?)	`$1`	❔
(?)	$`	❔
(?)	`$&`	❔
(?)	`x20`	❔
(?)	`x{06fa}`	❔
variables / macros		❓
regex optimization		❓
standard library / patterns		❓
reverse compiler		❓

Acknowledgments

Melody uses: