punyexpr
v1.0.4
Published
A minimalist expression compiler and evaluator
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9,702
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punyexpr 🦴
A minimalist (4955 bytes) expression compiler and evaluator.
Live demo
https://arnaudbuchholz.github.io/punyexpr/samples/calc.html
Usage
1. Include the punyexpr helper
<script src="https://cdn.jsdelivr.net/npm/punyexpr/dist/punyexpr.js"></script>
2. Compile an expression
const incValue = punyexpr('value + 1')
3. Evaluate the expression
incValue({ value: 1 }) // 2
Use with punybind@>=1.2.0
const safebind = punybind.use({
compiler: punyexpr
})
// Use safebind to bind HTML
Implementation notes
Regular expressions are not secure and are not allowed by default
Leverage the option
{ regex: true }
to enable regular expressions using the default JavaScript implementation:
const unsecure = punyexpr('value.match(/a+b/)', { regex: true })
- Or plug any custom regular expression builder using
{ regex: (pattern, flags) => { /* */ } }
const unsecure = punyexpr('value.match(/a+b/)', { regex: (pattern, flags) => new RegExp(pattern, flags) })
- Check the source for the (altered and) implemented grammar, in particular the following are not supported :
- Bitwise, async and coalesce operations
new
andthis
- Object literals
- See the tests for supported expressions.
- The implementation is compliant with Content Security Policy.