Freeze the vertical-slice subset #79

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opened 2026-10-04 02:37:21 +00:00 by jacksonopp · 0 comments

jacksonopp commented

2026-10-04 02:37:21 +00:00

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Design/risk issue, same shape as #69/#76 - decide this before writing any codegen.

Explicitly freeze what's in and out of the vertical slice, so later steps have a fixed target:

In:

Int/Bool literals, arithmetic/comparison ops
let/var bindings and reassignment
if/else as a value-producing expression
non-generic fn definitions and calls

Out, explicitly unreachable from this subset (not just "unused"):

fail(Reason)/?/where fails
the effect system
generics
structs/enums/arrays/maps/strings
loops
concurrency (sync/race/rush/branch/spawn)

The "explicitly unreachable" framing matters: the point of this milestone is to not need rework once Step 3/4 land, so nothing in the slice should quietly assume semantics (e.g. "this function can't fail") that later steps will contradict.

Also decide:

The entry-point convention (fn main() -> Int? something else?)
How output is observed - process exit code, a minimal print builtin calling back into a tiny Rust runtime function, or both

This issue blocks every other issue in the milestone.

Design/risk issue, same shape as #69/#76 - decide this before writing any codegen. Explicitly freeze what's in and out of the vertical slice, so later steps have a fixed target: **In:** - `Int`/`Bool` literals, arithmetic/comparison ops - `let`/`var` bindings and reassignment - `if`/`else` as a value-producing expression - non-generic `fn` definitions and calls **Out, explicitly unreachable from this subset** (not just "unused"): - `fail(Reason)`/`?`/`where fails` - the effect system - generics - structs/enums/arrays/maps/strings - loops - concurrency (`sync`/`race`/`rush`/`branch`/`spawn`) The "explicitly unreachable" framing matters: the point of this milestone is to not need rework once Step 3/4 land, so nothing in the slice should quietly assume semantics (e.g. "this function can't fail") that later steps will contradict. Also decide: - The entry-point convention (`fn main() -> Int`? something else?) - How output is observed - process exit code, a minimal `print` builtin calling back into a tiny Rust runtime function, or both This issue blocks every other issue in the milestone.

jacksonopp added this to the Vertical Slice: Minimal End-to-End Backend milestone

2026-10-04 02:37:21 +00:00

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2026-10-04 02:37:21 +00:00