Migration Guide

This guide covers breaking and notable changes between MIRR compiler versions. Each version section is organized by audience.

0.1.0 → 0.2.0

For Rust API Consumers

New enum variants on PropertyFormula

PropertyFormula now has 6 variants (was 3). If your code matches on this enum without a wildcard arm, you must handle the new variants:

The exprs() and exprs_mut() methods on PropertyFormula handle all 6 variants, so code using those methods needs no changes.

New directive field on PropertyDecl

PropertyDecl has a new field:

pub directive: PropertyDirective,  // Assert (default), Cover, Assume

It is annotated with #[serde(default)], so JSON deserialization of old data still works (defaults to Assert).

New fields on Module

Three new fields were added to Module:

All three have #[serde(default)], so deserialization of old JSON is backward-compatible.

New public types

New public functions

For JSON Netlist Consumers

New top-level field: schema_version

The JSON netlist now includes a schema_version field as the first key:

{
  "schema_version": "0.2.0",
  "ir_version": "1.0",
  ...
}

ir_version remains "1.0" and tracks the IR contract version. schema_version tracks the JSON output schema and will be bumped when fields are added, removed, or renamed.

Action required: If your JSON parser rejects unknown fields, allow schema_version (type: string).

properties array is always present

Previously, the properties key was absent when no properties existed. Now it is always present as an array (may be empty []).

Property objects have new fields and values

Each object in the properties array now has:

pattern_origins array (conditional)

When a module uses pattern calls, a pattern_origins array appears:

"pattern_origins": [
  { "pattern_name": "threshold_guard", "args_summary": "temperature, 100, 5, temp_alarm" }
]

This array is omitted (not present) when empty.

For MIRR Syntax / Tool Authors

New keywords in property blocks

Five new keywords are recognized inside property blocks:

These keywords only have special meaning inside property {} blocks. They do not affect parsing of signal, guard, or reflex blocks.

New top-level keywords: def and reflect

The pattern system introduces two new top-level constructs:

def pattern_name(param1: type, ...) {
    reflect {
        guard ... { ... }
        reflex ... { ... }
        property ... { ... }
    }
}

Pattern calls appear at module scope: pattern_name(arg1, arg2, ...);

For Error Message Parsers

All error messages now start with a structured error code prefix:

If you parse error output, you can now match on the [Ennn] prefix to categorize errors programmatically.

0.2.0 → 0.3.0

Version 0.3.0 ships the results of 8 implementation campaigns. This section covers all breaking and notable changes.

Campaign summary

For Rust API Consumers

New public types

New public functions

New PipelineConfig fields

Two new boolean fields control the additional pipeline stages:

Both fields default to false for backward compatibility. Existing PipelineConfig values continue to work without modification.

New enum variants

SignalType gains a Signed(u8) variant (TYPE-001). If your code matches on SignalType without a wildcard arm, you must handle:

SignalType::Signed(width) => { /* i8, i16, i32, i64 */ }

UnaryOp gains a Negate variant (TYPE-001). If your code matches on UnaryOp, add:

UnaryOp::Negate => { /* unary minus, e.g. -x */ }

PatternParamKind gains a Pattern variant (TYPE-005). Pattern parameters can now accept other patterns as arguments via PatternArg::PatternRef.

For JSON Netlist Consumers

schema_version bumped to "0.3.0"

The schema_version field is now "0.3.0". ir_version remains "1.0".

Signal objects may contain signed: true

Signals declared with signed types (i8, i16, i32, i64) include a "signed": true field. Unsigned signals omit this field or set it to false.

For MIRR Syntax / Tool Authors

Signed type keywords

Four new type keywords are recognized in signal declarations:

prev() temporal back-reference

The prev(signal, delay) built-in is now available in guard and reflex expressions. The delay argument must be a positive integer (≥ 1).

Higher-order pattern arguments

Pattern definitions can now accept other patterns as parameters using the pattern parameter kind, enabling composition of reusable design patterns.

For Error Message Parsers

The structured error code table is extended with the following new entries:

The full error code table (0.1.0 through 0.3.0) is:

See Also

• Error Codes — Complete error code catalogue
• Type System — New type rules added in 0.2.0+
• R-SPU ISA Spec — R-SPU backend added in 0.3.0
• Tutorial — Updated for all current features
• Roadmap — Upcoming changes to plan for