Files
Joseph Doherty
d5034c40f7
Phase 3 PR 63 -- S7AddressParser for DB/M/I/Q/T/C address strings. Adds S7AddressParser + S7ParsedAddress + S7Area + S7Size to the Driver.S7 project. Grammar follows driver-specs.md \u00A75 + Siemens TIA Portal / STEP 7 Classic convention: (1) Data blocks: DB{n}.DB{X|B|W|D}{offset}[.bit] where X=bit (requires .bit suffix 0-7), B=byte, W=word (16-bit), D=dword (32-bit). (2) Merkers: MB{n}, MW{n}, MD{n}, or M{n}.{bit} for bit access. (3) Inputs + Outputs: same {B|W|D} prefix or {n}.{bit} pattern as M. (4) Timers: T{n}. (5) Counters: C{n}. Output is an immutable S7ParsedAddress record struct with Area (DataBlock / Memory / Input / Output / Timer / Counter), DbNumber (only meaningful for DataBlock), Size (Bit / Byte / Word / DWord), ByteOffset (also timer/counter number when Area is Timer/Counter), BitOffset (0-7 for Size=Bit; 0 otherwise). Case-insensitive via ToUpperInvariant, whitespace trimmed on entry. Parse throws FormatException with the offending input echoed in the message; TryParse returns bool for config-validation callers that can't afford exceptions (e.g. Admin UI tag-editor live validation). Strict rejection policy -- 16 garbage cases covered in the theory test: empty/whitespace input, unknown area letter (Z0), DB without number/tail, DB bit size without .bit suffix, bit offset 8+, word/dword with .bit suffix, DB number 0 (must be >=1), non-numeric DB number, unknown size letter (Q), M without offset, M bit access without .bit, bit 8, negative offset, non-digit offset, non-numeric timer. Strict rejection surfaces config errors at driver-init time rather than as BadInternalError on every Read against the bad tag. No driver code wires through yet -- PR 64 is where IReadable/IWritable consume S7ParsedAddress and translate into S7netplus Plc.ReadAsync calls (the S7.Net address grammar is a strict subset of what we accept, and the parser's S7ParsedAddress is the bridge). Unit tests (S7AddressParserTests, 50 facts): parse-valid theories for DB/M/I/Q/T/C covering all size variants + edge bit offsets 0 and 7; case-insensitive + whitespace-trim theory; reject-invalid theory with 16 garbage cases; TryParse round-trip for valid and invalid inputs. 50/50 pass, dotnet build clean.