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overlookmotel
a4478e960a
Add `oxc-codegen` package - a printer written in TS. ### Features - Prints JS, JSX, TS, TSX. - Matches `oxc_codegen` exactly on all Test262, TypeScript, Acorn-JSX fixtures. - Very fast. ### Deficiencies - Pretty-printing only (no compact/minified output). - No support for printing comments. - Source map support is semi-there, but largely untested, and poor API (design doc has some ideas on how to improve it). ### This PR adds - The printer code. - Conformance testing infra. - Further tests for edge cases. - README. - Design doc - how it differs from `oxc_codegen` and why, what produces the perf. ### This PR doesn't add - Not integrated into CI or release pipeline. ### Notes This started as a slop port of `oxc_codegen`. I've iterated on that base, cleaned it up a lot, and at least skimmed through all of it. I think it's in fairly decent shape. The design doc is I think worth a read. It explains the rationale for the choices, in particular the "1 codebase, 4 builds" approach. I've put it in a new top-level directory called `packages`. It's not an app, so didn't seem to me to fit alongside `apps/oxlint` and `apps/oxfmt`. It's pure JS, so not like e.g. `napi/parser`. And it felt too heavyweight to put into `npm` dir. But maybe there's a better place for it. Co-authored-by: Cameron <cameron.clark@hey.com>
30 lines
1.4 KiB
TypeScript
30 lines
1.4 KiB
TypeScript
// Operator precedence levels, on the scale `oxc_syntax::precedence::Precedence` uses.
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//
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// A printer is told the precedence of the position it is printing into, and parenthesizes itself
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// when its own precedence is lower. The numbering is Oxc's, so the two agree on what needs parens.
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/** No precedence at all - nothing parenthesizes itself against this. */
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export const PREC_LOWEST = 0;
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/** The comma operator, as in a sequence expression. */
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export const PREC_COMMA = 1;
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/** `yield` and `yield*`. */
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export const PREC_YIELD = 3;
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/** Assignment, including the compound and logical forms, and arrow functions. */
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export const PREC_ASSIGN = 4;
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/** The `?:` conditional operator. */
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export const PREC_CONDITIONAL = 5;
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/** The equality operators, `==` through `!==`. */
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export const PREC_EQUALS = 12;
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/** The relational operators, including `in` and `instanceof`. */
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export const PREC_COMPARE = 13;
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/** `**`, the one right-associative binary operator. */
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export const PREC_EXPONENTIATION = 17;
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/** The prefix unary and update operators, `await`, and `!`. */
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export const PREC_PREFIX = 18;
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/** The postfix update operators, and the position a member expression's object prints at. */
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export const PREC_POSTFIX = 19;
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/** `new` without an argument list, which binds tighter than a call. */
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export const PREC_NEW = 20;
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/** Calls, member access and tagged templates - the tightest binding there is. */
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export const PREC_CALL = 21;
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