Pros of TOML

• Simple and human-readable configuration file format
• Widely adopted in various programming languages and tools
• Stricter and less ambiguous than alternatives like YAML

Cons of TOML

• Limited expressiveness compared to Ohm's parsing capabilities
• Focused solely on configuration, while Ohm is a general-purpose parsing toolkit
• Less flexibility for complex data structures or custom grammars

Code Comparison

TOML example:

[database]
server = "192.168.1.1"
ports = [ 8001, 8001, 8002 ]
connection_max = 5000

Ohm grammar example:

Arithmetic {
  Exp     = AddExp
  AddExp  = AddExp "+" MulExp  -- plus
          | AddExp "-" MulExp  -- minus
          | MulExp
  MulExp  = MulExp "*" PriExp  -- times
          | MulExp "/" PriExp  -- divide
          | PriExp
  PriExp  = "(" Exp ")"        -- paren
          | number
  number  = digit+
}

TOML is designed for simple configuration files, making it easy to read and write. It's widely supported across languages and tools. However, it lacks the flexibility and power of Ohm, which can define complex grammars for parsing various languages and formats. Ohm provides a more comprehensive toolkit for language processing tasks, while TOML focuses on a specific use case of configuration management.

Pros of PEG.js

• More mature and widely adopted, with a larger community and ecosystem
• Supports generating parsers in multiple target languages (JavaScript, TypeScript, Rust)
• Offers a web-based editor for testing and debugging grammars

Cons of PEG.js

• Less flexible grammar syntax compared to Ohm
• Limited support for incremental parsing and error recovery
• Steeper learning curve for complex grammars

Code Comparison

PEG.js grammar example:

Expression
  = head:Term tail:(_ ("+" / "-") _ Term)* {
      return tail.reduce(function(result, element) {
        if (element[1] === "+") { return result + element[3]; }
        if (element[1] === "-") { return result - element[3]; }
      }, head);
    }

Ohm grammar example:

Arithmetic {
  Exp   = AddExp
  AddExp = AddExp "+" MulExp  -- plus
         | AddExp "-" MulExp  -- minus
         | MulExp
  MulExp = MulExp "*" PriExp  -- times
         | MulExp "/" PriExp  -- divide
         | PriExp
  PriExp = "(" Exp ")"        -- paren
         | number
  number = digit+
}

Pros of Parsimmon

• More flexible and customizable parsing approach
• Better performance for certain types of grammars
• Easier integration with existing JavaScript code

Cons of Parsimmon

• Steeper learning curve for complex grammars
• Less readable for non-programmers
• Lacks built-in error reporting and debugging tools

Code Comparison

Parsimmon:

const P = require('parsimmon');
const parser = P.string('hello')
  .then(P.string(' '))
  .then(P.string('world'));

Ohm:

const ohm = require('ohm-js');
const grammar = ohm.grammar(`
  Greeting = "hello" " " "world"
`);

Summary

Parsimmon offers more flexibility and potentially better performance for certain use cases, while Ohm provides a more declarative and readable approach to grammar definition. Parsimmon may be preferred by developers who want fine-grained control over parsing logic, while Ohm is often favored for its simplicity and built-in tooling. The choice between the two depends on the specific requirements of the project and the preferences of the development team.

Pros of ohm

• More actively maintained with recent updates
• Larger community and contributor base
• Better documentation and examples

Cons of ohm

• Potentially more complex for simple use cases
• May have more dependencies

Code Comparison

ohm:

const ohm = require('ohm-js');
const grammar = ohm.grammar(`
  Arithmetic {
    Exp = AddExp
    AddExp = AddExp "+" MulExp  -- plus
           | AddExp "-" MulExp  -- minus
           | MulExp
    MulExp = MulExp "*" PriExp  -- times
           | MulExp "/" PriExp  -- divide
           | PriExp
    PriExp = "(" Exp ")"  -- paren
           | number
    number = digit+
  }
`);

ohm>:

// No direct code comparison available as ohm> is not a separate repository
// It appears to be a typo or misunderstanding in the original question

Note: The comparison to "ohm>" seems to be an error, as there is no separate repository named "ohmjs/ohm>". The comparison is based solely on the ohm repository.

Pros of Chevrotain

• Better performance for large-scale parsing tasks
• More flexible and customizable parsing approach
• Extensive documentation and examples for various use cases

Cons of Chevrotain

• Steeper learning curve, especially for beginners
• Requires more boilerplate code for simple grammars
• Less intuitive syntax for defining grammar rules

Code Comparison

Ohm grammar example:

Arithmetic {
  Exp     = AddExp
  AddExp  = AddExp "+" MulExp  -- plus
          | AddExp "-" MulExp  -- minus
          | MulExp
  MulExp  = MulExp "*" PriExp  -- times
          | MulExp "/" PriExp  -- divide
          | PriExp
  PriExp  = "(" Exp ")"        -- paren
          | number
  number  = digit+
}

Chevrotain lexer and parser example:

const createToken = chevrotain.createToken;
const Lexer = chevrotain.Lexer;
const CstParser = chevrotain.CstParser;

const Plus = createToken({ name: "Plus", pattern: /\+/ });
const Minus = createToken({ name: "Minus", pattern: /-/ });
const Mult = createToken({ name: "Mult", pattern: /\*/ });
const Div = createToken({ name: "Div", pattern: /\// });

Both Ohm and Chevrotain are powerful parsing libraries, but they cater to different needs and preferences. Ohm focuses on simplicity and readability, while Chevrotain offers more control and performance at the cost of complexity.

Pros of ANTLR4

• Supports multiple target languages (Java, C#, Python, JavaScript, etc.)
• Extensive documentation and large community support
• Powerful parsing capabilities with built-in error recovery

Cons of ANTLR4

• Steeper learning curve, especially for complex grammars
• Can be overkill for simpler parsing tasks
• Generated code can be verbose and less readable

Code Comparison

ANTLR4 grammar example:

grammar Expression;
expr : term (('+' | '-') term)*;
term : factor (('*' | '/') factor)*;
factor : NUMBER | '(' expr ')';
NUMBER : [0-9]+;
WS : [ \t\r\n]+ -> skip;

Ohm grammar example:

Expression {
  Expr = Term (("+" | "-") Term)*
  Term = Factor (("*" | "/") Factor)*
  Factor = number | "(" Expr ")"
  number = digit+
}

Both ANTLR4 and Ohm are powerful parsing tools, but they cater to different needs. ANTLR4 is more feature-rich and versatile, supporting multiple languages and complex parsing scenarios. However, it can be more challenging to learn and use for simpler tasks. Ohm, on the other hand, offers a more concise and readable grammar syntax, making it easier to use for smaller projects or when working primarily with JavaScript. The choice between the two depends on the specific requirements of your project and your familiarity with parsing concepts.