# zero-copy-parser 🦾

> "Parse, don't validate."


A strict, type-safe parser combinator library for TypeScript. 

## Philosophy

- **Correctness**: If it compiles, it parses (mostly).
- **Zero-Copy**: We pass indices, not substrings. Allocation only happens on yield.
- **Explicit**: Errors are values, not exceptions.

## Usage

```typescript
import { 
  tag, 
  sequence, 
  map, 
  digit1, 
  separatedList0, 
  delimited, 
  multispace0 
} from 'zero-copy-parser';

// Parse "[1, 2, 3]"
const numberParser = map(digit1, Number);
const arrayParser = delimited(
  tag("["),
  separatedList0(
    numberParser, 
    sequence(tag(","), multispace0)
  ),
  tag("]")
);

const result = arrayParser("[1, 2, 3]", 0);
// Result: Ok([1, 2, 3])
```

## Combinators

- `tag(str)`: Match exact string
- `sequence(...parsers)`: Match in order
- `alt(...parsers)`: Match first success
- `map(parser, fn)`: Transform result
- `many0(parser)`: 0 or more
- `takeWhile(pred)`: 0 or more chars matching predicate
- `takeWhile1(pred)`: 1 or more chars
- `optional(parser)`: Match or null
- `oneOf(chars)` / `noneOf(chars)`: Character class
- `separatedList0(parser, separator)`: List with separator
- `delimited(start, parser, end)`: Between brackets/tags

## Pre-built

- `digit1`: One or more digits
- `alpha1`: One or more letters
- `multispace0`: Whitespace

## Contributions

PRs welcome. Keep it strict. Keep it typed.