feat(echo): surface @echo(...) function-grade annotation + upper-bound check (ADR-0009 D1)

[hyperpolymath]

Surfaces the Echo grade in the function arrow — the "Echo as a first-class function effect" surface slice of ADR-0009 D1 (the proof + effect-composition halves already landed). Built as Bundle A (the design we settled on): parameterised syntax + upper-bound policy.

Syntax — @echo(Safe|Neutral|Breaking)

@echo(Neutral) fn f(x: Int): Int { ... }
@pure @echo(Breaking) fn g(): Int { ... }   // order-independent with @pure/@total

One directive carrying the grade (grammar echo_marker; the parser consumes leading markers in a loop) — scales cleanly to a later @epi(...).

AST — and the cycle break

FunctionDecl.echo_annotation: Option<Echo>. The Echo enum moves from echo.rs to ast.rs so the AST can hold it without the ast↔echo module cycle, and is re-exported pub use crate::ast::Echo from echo.rs — so every existing echo::Echo site is unchanged.

Check — upper bound (inferred ⊑ annotated)

typechecker::check_echo_annotations (a 3rd pass of check_program) verifies the inferred grade doesn't exceed the declared ceiling, against the carrier-aware, call-graph-composed effect::resolved_effects. A function may declare more loss than it incurs, never less — so a caller can be checked against a callee's declared ceiling (modular).

Soundness note: the reverse {} gate still classifies against the actual inferred grade, never the annotation — so no annotation can loosen reversal soundness. The annotation governs the published interface grade only.

Round-trip

pretty.rs + formatter.rs emit @echo(...) after purity, pinned by a pretty-printer round-trip test (annotations no longer drop on format).

Tests / quality

6 new tests (parse + either-order; upper-bound accept/reject/absent; round-trip). 133 lib tests, cargo fmt + clippy clean.

Remaining (noted in effect.rs + STATE)

The grade carried in TypeAnnotation::Function (for function-valued params) and the parallel @epi(...) surface.

🤖 Generated with Claude Code

https://claude.ai/code/session_01BJmfoz1ZS1Pejy9LLMY742

---

Generated by Claude Code

[github-actions]

🔍 Hypatia Security Scan

Findings: 55 issues detected

Severity	Count
🔴 Critical	0
🟠 High	23
🟡 Medium	32

View findings

[
  {
    "reason": "No test directory or test files found",
    "type": "no_tests",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper",
    "action": "flag",
    "rule_module": "honest_completion",
    "severity": "high",
    "deduction": 20
  },
  {
    "reason": "Issue in secret-scanner.yml",
    "type": "missing_workflow",
    "file": "secret-scanner.yml",
    "action": "create",
    "rule_module": "workflow_audit",
    "severity": "high"
  },
  {
    "reason": "Issue in scorecard.yml",
    "type": "scorecard_wrapper_missing_job_permissions",
    "file": "scorecard.yml",
    "action": "flag",
    "rule_module": "workflow_audit",
    "severity": "high"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (10 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/crates/jtv-core/benches/interpreter_bench.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  },
  {
    "reason": "unwrap() without prior check -- DoS via panic (6 occurrences, CWE-754)",
    "type": "unwrap_without_check",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/crates/jtv-core/benches/parser_bench.rs",
    "action": "flag",
    "rule_module": "code_safety",
    "severity": "high"
  },
  {
    "reason": "Js.Array2 deprecated -- use Array (3 occurrences)",
    "type": "deprecated_api",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/vscode-extension/src/Extension.res",
    "action": "search_replace",
    "rule_module": "migration_rules",
    "severity": "high"
  },
  {
    "reason": "Js.Promise deprecated -- use Promise (2 occurrences)",
    "type": "deprecated_api",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/vscode-extension/src/Extension.res",
    "action": "module_replace",
    "rule_module": "migration_rules",
    "severity": "medium"
  },
  {
    "reason": "Belt.Array deprecated -- use Array (30 occurrences)",
    "type": "deprecated_api",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/packages/jtv-analyzer/src/Main.res",
    "action": "module_replace",
    "rule_module": "migration_rules",
    "severity": "high"
  },
  {
    "reason": "Belt.Option deprecated -- use Option (2 occurrences)",
    "type": "deprecated_api",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/packages/jtv-analyzer/src/Main.res",
    "action": "module_replace",
    "rule_module": "migration_rules",
    "severity": "medium"
  },
  {
    "reason": "Js.Array2 deprecated -- use Array (7 occurrences)",
    "type": "deprecated_api",
    "file": "/home/runner/work/julia-the-viper/julia-the-viper/packages/jtv-analyzer/src/Main.res",
    "action": "search_replace",
    "rule_module": "migration_rules",
    "severity": "high"
  }
]

Powered by Hypatia Neurosymbolic CI/CD Intelligence