Patrick Walton
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pcwalton.bsky.social
Patrick Walton
@pcwalton.bsky.social
2.5K followers 41 following 130 posts
Programming languages and graphics person. Rust compiler, Firefox, and Bevy contributor. Currently working on an unannounced project!
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pcwalton.bsky.social
I think I just answered my own question, from Kent Dybvig's 1987 dissertation agl.cs.unm.edu/~williams/cs...
Lexical variable bindings are recorded in an environment structure. The environment is a list of pairs of lists, the two lists in each pair being a list of variables and a corresponding list of values. During the evaluation of any expression, the list of pairs corresponds to the nesting of the lambda expressions surrounding the expression; the first pair of lists contains the bindings for the closest enclosing lambda, the second contains the bindings for the next enclosing lambda, and so on. This environment representation is often referred to as a rib cage because of its structure, and the list of variables and list of values are referred to as variable and value ribs. This structure is used as well in Chapter 3 and is described more completely there.
August 12, 2025 at 11:26 PM
pcwalton.bsky.social
Also something I realized: AArch64 has a scaled base + index addressing mode, so the lookup and branch in the compressed instruction case is 3 instructions. godbolt.org/z/nnWKcPcWc
May 9, 2025 at 6:08 PM
pcwalton.bsky.social
And they say that comptime is better than generics.
May 2, 2025 at 7:17 PM