Claude Code transcript

6 prompts · 75 messages · 28 tool calls · 1 commits · 2 pages

#1

Implement the following plan:

Fix: Channel array slices incompatible with direction-restricted params (#57)

Context

When a proc parameter is []CHAN BYTE in?, codegen emits in []<-chan byte. Callers passing []chan byte fail to compile because Go slices are not covariant — []chan byte cannot be assigned to []<-chan byte. This blocks transpilation of sort_pump.occ and other programs that pass channel arrays to direction-annotated params.

Approach: Drop direction from channel array params

Generate []chan T instead of []<-chan T / []chan<- T for channel array parameters. Single-channel params (CHAN OF INT c?) continue to use direction prefixes since Go individual channels ARE covariant.

Rationale: The codegen has no type-tracking system to know whether an argument is already directional, making call-site conversion loops impractical. Occam enforces direction safety at the source level, so the transpiler doesn't need to re-enforce it in Go. This is a one-line fix with no risk of regression.

Changes

1. codegen/codegen.go line 2039 — Drop direction for channel arrays

// Before:
goType = "[]" + chanDirPrefix(p.ChanDir) + g.occamTypeToGo(p.ChanElemType)
// After:
goType = "[]chan " + g.occamTypeToGo(p.ChanElemType)

2. codegen/codegen_test.go lines 617-629 — Update unit test assertions

Update TestChanArrayDirParamGen to expect []chan int for both ? and ! directions.

3. codegen/e2e_array_test.go — Add e2e test

Add TestE2E_ChanArrayDirParam that passes a [n]CHAN OF INT array to a proc with []CHAN OF INT in? and []CHAN OF INT out! params. Verifies the transpiled code compiles and runs correctly.

4. CLAUDE.md — Update mapping table

Add row documenting that direction is dropped for channel array params.

Verification

go test ./codegen -run TestChanArrayDirParamGen   # updated unit test
go test ./codegen -run TestE2E_ChanArrayDirParam  # new e2e test
go test ./...                                      # full suite
# Course module regression check:
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/course_out.go kroc/modules/course/libsrc/course.module && go vet /tmp/course_out.go
# Repro from issue:
./occam2go -I kroc/modules/course/libsrc -D TARGET.BITS.PER.WORD=32 -o /tmp/sort_pump.go kroc/modules/course/examples/sort_pump.occ && go vet /tmp/sort_pump.go

If you need specific details from before exiting plan mode (like exact code snippets, error messages, or content you generated), read the full transcript at: /home/david/.claude/projects/-home-david-projects-code-associates-occam2go/2e133da4-2875-49f0-ade2-e7a0ac8c9763.jsonl

5 read · 5 bash · 5 edit · 2 taskupdate · 1 grep · 1 taskcreate

All done. Here's a summary of the changes:

  1. codegen/codegen.go:2039 — Changed channel array param generation from "[]" + chanDirPrefix(p.ChanDir) + ... to "[]chan " + ..., dropping direction prefixes for array params (Go slices aren't covariant).

  2. codegen/codegen_test.go:623-628 — Updated TestChanArrayDirParamGen assertions to expect []chan int instead of []<-chan int / []chan<- int.

  3. codegen/e2e_array_test.go — Added TestE2E_ChanArrayDirParam that passes a [3]CHAN OF INT array to procs with ? and ! direction annotations, verifying it compiles and runs correctly.

  4. CLAUDE.md — Added two rows documenting that direction is dropped for []CHAN OF INT cs? and []CHAN OF INT cs! array params.

All tests pass, course module regression passes, and sort_pump.occ now transpiles and vets cleanly.

#2

Thank you. Please create a PR for this fix.

7 bash
235652f
Drop direction from channel array params to fix Go slice covariance issue
#3

Thank you. If the PR has been approved and CI checks have passed, please merge it.

2 bash
#5

/exit exit

#6

See ya!

#4

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