Changelog

All notable changes are recorded here. The format follows Keep a Changelog, and versions follow Semantic Versioning.

Unreleased

A Windows source path no longer breaks the generated module. The path is embedded in the module docstring, where a backslash is an escape sequence, so D:\a\plant\Motor.scl produced Python that would not parse. Paths and comments are now escaped wherever they land in a docstring, and a source path containing *) can no longer close a Structured Text comment early.

plcforge scaffold: generates a complete, installable Python repository with a vendored runtime, an entry point that runs the scan cycle, tests and packaging metadata. The result has no dependency on plcforge.
Python frontend: lifts Python control code back into the IR, so a project can go SCL to Python and back and still be recognisable.
Implicit Python locals are declared in a VAR_TEMP block with the type the resolver derived, rather than being dropped.
plcforge lift as a direct route from Python to Structured Text.

A return <value> inside a lifted function is assigned to the function result instead of being lost.
The section markers that group variables (# VAR_INPUT) are read from the source that was handed in, not re-read from disk, so lifting a string works.

C++17 backend with a header-only runtime: types, standard blocks, bounds checked arrays and a scan engine.
CASE over single labels becomes a switch; ranges become a branch chain.
--namespace and --no-runtime for the C++ target.

LIMIT, MIN, MAX and SEL deduce a common type, so mixing REAL and a double literal compiles.
A negated literal loop step (BY -1) is folded at translation time, so the loop comparison is chosen statically rather than at run time.
An undeclared FOR counter is declared in the generated C++, which Structured Text permits and C++ does not.

PLCopen XML frontend for Ladder Diagram and Function Block Diagram: contacts, coils, set/reset and negated coils, parallel branches, operator blocks, function block instances and executionOrderId.
Edge sensitive contacts create an implicit R_TRIG/F_TRIG instance.
Structured Text backend, which is what makes a ladder rung reviewable as text.
Diagnostics carry a code and a hint.

A block whose outputs nothing reads is still called, instead of being skipped.
Dangling connections and unsupported body languages are reported rather than producing an empty POU with no explanation.

Structured Text / SCL frontend: full statement set, IEC operator precedence, structures, enumerations, multi-dimensional arrays, based and duration literals, direct addresses, nested comments and pragmas.
Typed intermediate representation with a resolver that annotates every expression.
Python backend with a scan-cycle runtime: injectable clocks, the standard function blocks and the IEC functions where Python's operators disagree.
Error recovery: a malformed statement is reported and parsing continues.
Command line interface: convert, check, info.