`JOIN WITH <alias> TO <file> [FIELDS <list>] [FOR <expr>]` becomes a
preprocessor rewrite to a new RTL primitive __dbJoin. Cartesian
product of the current ("master") workarea and the named "detail"
alias, filtered by the FOR expression.
Output structure:
* No FIELDS clause: master's fields followed by detail's, dropping
any detail-side name that clashes with master.
* FIELDS list: one column per name in declaration order, resolved
against master first then detail.
Same shape as harbour-core/src/rdd/dbjoin.prg. Five-specific
simplifications: alias->name in FIELDS not yet supported (bare
names with master-precedence lookup); RDD/codepage args dropped
since Five only has DBFNTX.
Note for callers: don't name a workarea `M` or `MEMVAR` — both are
Harbour-reserved memvar aliases, so `M->field` and `MEMVAR->field`
always go through the memory-variable namespace, not the workarea.
This is gengo behavior matching Harbour, not new in this commit.
Parser cleanup: JOIN removed from the IDENT-statement no-op switch.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`TOTAL TO <file> ON <key> [FIELDS <list>] [FOR ...] [WHILE ...]
[NEXT ...] [RECORD ...] [REST] [ALL]` joins the family of std.ch
DML rewrites. New RTL primitive __dbTotal:
* Walk the source under dbEval-style FOR/WHILE/NEXT/RECORD/REST
bounds. The source must already be sorted/indexed on the key —
same precondition as Harbour's dbtotal.prg.
* Track the current group key. On each key change, flush the
accumulated row to the destination (writing the running totals
back into the most recently appended record's sum-fields,
preserving each field's declared length/decimals).
* On the *first* record of every group, append a fresh dst row
and copy all non-memo source fields into it; subsequent records
in the group only contribute to the sums. Net effect: non-summed
fields take the first record's value, summed fields hold the
group total. Same shape as harbour-core/src/rdd/dbtotal.prg.
* Memo fields are dropped from the destination structure (Harbour
does the same).
Parser cleanup: TOTAL removed from the IDENT-statement no-op switch.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`LIST [<fields>] [OFF] [FOR ...] [WHILE ...] [NEXT ...] [RECORD ...]
[REST] [ALL]` and `DISPLAY [<fields>] [OFF] [FOR ...] ... [ALL]`
reach the parser as plain function calls to a new RTL primitive
__dbList (rtlDbList in hbrtl/database.go).
Implementation: walk the workarea under dbEval-style FOR/WHILE/NEXT/
RECORD/REST bounds. For each visible record, evaluate each column
block and emit the rendered values via valueToDisplay (the same
formatter QOut already uses). Empty fields list defaults to
"all fields". OFF suppresses the record-number prefix.
LIST always emits the full filtered range; DISPLAY without ALL emits
only the current record (encoded as nCount=1). TO PRINTER / TO FILE
clauses are not yet wired through — for now everything goes to
stdout.
Wiring up LIST/DISPLAY surfaced four further gaps in PP that were
silently masking bugs in any rule with multiple word-list / list /
optional clauses chained together:
* matchSegment refused MarkerWordList inside `[...]`. The LIST
rule's `[<off:OFF>]` clause therefore never set the off
capture, and `<.off.>` substituted to nothing instead of .T./.F.
matchSegment now matches WordList markers the same way the
top-level matcher does.
* `<v,...>` and `<(f)>` capture stop boundaries didn't include the
values of following MarkerWordList markers. For
`[<v,...>] [<off:OFF>] [<all:ALL>]` against `LIST id, name OFF`,
the v list would happily eat OFF. New addStopFrom helper
contributes both literal keywords and word-list values; both
matchSegment's MarkerList branch and captureExpression now use
it.
* Optional-repeat loop in matchPattern merged a no-progress
iteration's empty capture into the running multi-capture string
(with the `\x01` separator) before the no-progress break check
fired. So a successful first iteration's value got contaminated
and the substitution loop then skipped it as multi-capture
garbage. The merge now happens after the progress check.
* Unreferenced `<.name.>` markers (optional clauses that didn't
match in the input) were getting cleaned up to empty by the
generic marker scrubber instead of the .F. sentinel Harbour's
std.ch expects. New replaceUnreferencedLogify pass mirrors the
existing replaceUnreferencedBlockify and runs just before the
cleanup.
Parser cleanup: LIST and DISPLAY removed from the IDENT-statement
no-op switch in both parseIdentStmt and parseExprStmt.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`SORT TO <file> [ON <key-list>] [FOR ...] [WHILE ...] [NEXT ...]
[RECORD ...] [REST] [ALL]` joins COPY in being a real preprocessor
rewrite to a function call. New RTL primitive __dbSort:
* Buffer visible source records (FOR/WHILE/NEXT/RECORD/REST same
as __dbCopy).
* Multi-key stable insertion sort. Each key may carry `/D` for
descending; ascending otherwise. /A and unknown suffixes fall
through as ascending. Comparison delegates to the existing
compareValues helper in sqlscan.go (numeric / string / NIL-aware).
* Create destination DBF with the source's struct, append rows in
sorted order, restore source selection.
Parser cleanup: SORT removed from the IDENT-statement no-op switch.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
`COPY TO <file> [FIELDS <list>] [FOR ...] [WHILE ...] [NEXT ...]
[RECORD ...] [REST] [ALL]` reaches the parser as a plain function
call to a new RTL primitive __dbCopy (rtlDbCopy in hbrtl/database.go).
Implementation: project the field list (case-insensitive name match
against the source's structure, full copy when omitted), dbCreate the
target file with that struct, open it under a temp alias, walk the
source under dbEval-style FOR/WHILE/NEXT/RECORD/REST bounds, and
GetValue/Append/PutValue per record into the target. SDF / DELIMITED
variants stay parser no-ops until those backends arrive.
Wiring up COPY surfaced four longstanding gaps in the PP that had to
be fixed for the rule to even reach the runtime:
* `<(name)>` *pattern* marker was treated as a regular `<name>`
with the parens baked into the captured key, so the matching
result substitution `<(name)>` couldn't find it. parseOneMarker
now strips the parens at parse time so capture key and result
marker share the bare name. The smart-stringify result behavior
is unchanged.
* matchSegment (the optional-clause matcher) bailed on every
non-Regular marker. `[FIELDS <fields,...>]` therefore failed to
match at all and the fields list arrived empty in the result
template. matchSegment now handles MarkerList with paren-balanced
capture and segment+outer literal stop boundaries.
* captureExpression only used the first literal in the pattern
tail as a stop boundary. With std.ch's chain of optional
clauses (`[TO <(f)>] [FIELDS ...] [FOR ...] [WHILE ...] ...`)
the file-name marker was happy to gobble a trailing FOR clause
when FIELDS was absent. It now stops at *any* of the remaining
pattern literals.
* `<(name)>` smart-stringify on a list-typed capture wrapped the
whole comma-joined string in one set of quotes — `{ "a , b" }` —
instead of `{ "a", "b" }`. New helper quoteListElements splits on
top-level commas (paren / bracket / brace / string-balanced) and
quotes each element. applyResult now consults the rule's marker
table to know which captures came from `<name,...>`.
Parser cleanup: COPY removed from the IDENT-statement no-op switch in
both parseIdentStmt and parseExprStmt.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Three xBase analytical commands that were silent no-ops in the
parser now execute as Harbour-style PP rewrites:
COUNT [TO <v>] [FOR <for>] [WHILE <while>] ... -> dbEval()
SUM <x> TO <v> [FOR <for>] [WHILE <while>] ... -> dbEval()
AVERAGE <x> TO <v> [FOR ...] -> __dbAverage()
COUNT and SUM expand to a `<v> := 0 ; dbEval( {|| ... } )` pair
matching harbour-core/include/std.ch verbatim. AVERAGE delegates to
a new RTL function rtlDbAverage (sum + count + divide; returns 0 on
empty match) — the chained-private-variable trick Harbour uses to
keep AVERAGE inline doesn't translate cleanly through Five's PP.
Wiring up these rules surfaced four PP issues that had to be fixed
for the rewrite to even reach the parser:
* Result template did not implement <{name}> blockify. So a rule
body like `{|| x := x + <x> }, <{for}>` left the literal text
`<{for}>` in the output. Added blockify substitution: captured
-> `{|| <captured> }`, missing -> NIL.
* findMarkerEnd did not recognise `{`/`}` so unreferenced
blockify markers were not cleaned up either. Added `{`/`}` to
its prefix/suffix sets.
* Optional-clause matching had no view of the outer pattern, so a
regular marker at the end of `[TO <v>]` would swallow the rest
of the line — `COUNT TO n FOR x>5` captured `<v>` as
"n FOR x>5". matchSegment now takes outerTail and stops at its
first literal.
* `#command` directives could not span multiple physical lines.
A trailing `;` is harbour-core's line-continuation marker for
std.ch and now joins the next line into the directive before
parsing.
Parser cleanup: COUNT, SUM, AVERAGE removed from the IDENT-statement
no-op switch in parseIdentStmt + parseExprStmt. The remaining xBase
verbs (COPY, SORT, TOTAL, JOIN, LIST, DISPLAY, LABEL, REPORT, ...)
stay in the parser until their RTL backends arrive.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Introduce compiler/pp/std.ch with 19 #command rules so that ERASE,
RENAME, DELETE FILE, CLOSE [<a>|ALL|DATABASES], COMMIT, UNLOCK,
LOCATE/CONTINUE, REINDEX, PACK, ZAP, KEYBOARD, RUN, MENU TO, and
CLEAR GETS reach the parser pre-rewritten as plain function calls.
Embedded into the compiler binary via //go:embed so it auto-loads
without an explicit #include in user code, exactly the way Harbour
auto-loads its std.ch.
This is a pure dispatch move, not a behavior change for the
already-working forms: the same Five RTL functions get called.
But it does fix three regressions that the parser was masking:
* ERASE / RENAME / DELETE FILE used to be silent no-ops — the
parser swallowed the entire line and returned NIL. They now
actually delete/rename files (FErase / FRename).
* CLOSE <alias> used to silently ignore the alias and close the
current area. It now switches to the named area first
(<a>->( DbCloseArea() )).
* Two latent #command matcher bugs that surfaced while wiring
std.ch up:
- bare `CLOSE` would match rule `CLOSE ALL` because the tail
of the pattern wasn't checked for unconsumed literals.
- bare `CLOSE` would match rule `CLOSE <a>` because all
unconsumed pattern markers were unconditionally treated as
optional. They are only optional when nested inside `[...]`.
Parser cleanup: parseIdentStmt + parseExprStmt no longer hardcode
ERASE / RENAME / RUN / KEYBOARD / REINDEX / LOCATE / CONTINUE /
COMMIT / CLOSE — the rewriter handles them. Other xBase verbs
(COPY / SORT / COUNT / SUM / AVERAGE / TOTAL / JOIN / LIST /
DISPLAY / LABEL / REPORT / DIR ...) still no-op in the parser
because their RTL backends aren't implemented yet — once the
backends land they move into std.ch the same way.
Gates green:
go test ./... : PASS
FiveSql2 SQL:1999 : 43/43
Harbour compat : 56/56
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Two related fixes for Harbour's data-driven `USE &cFile ALIAS &cAlias
INDEX &cNdx` idiom — common in any app that dispatches table names
at runtime.
Parser (compiler/parser/parser.go parseUse):
- `USE &cFile` / `USE &(expr)` previously triggered a
skipToEndOfLine short-circuit, emitting an empty UseCmd (equivalent
to bare USE = close current area). Now parseMacro runs and the
MacroExpr becomes the File node, so codegen emits MacroPush +
dbUseArea.
- `ALIAS &cAlias` / `ALIAS &a.1` similarly dropped the macro result;
now captures it into UseCmd.AliasExpr so codegen evaluates the
alias at runtime. Both the IDENT-path ("ALIAS") and keyword-path
(token.ALIAS) handlers fixed.
PP (compiler/pp/command.go):
- captureExpression and the MarkerList branch now paren-balance
`(`/`[`/`{` so nested grouping inside a macro argument doesn't let
an inner `)` terminate the capture. Example:
_REGULAR_(&(a))
previously captured `&(a` (missing inner `)`) and left the outer
`)` dangling, producing parse errors in the expanded output.
- MarkerList capture still joins tokens with " " for raw `<z>`
substitution — comma tokens stay in the stream, so `s(<z>)`
re-emits them as argument separators and the list expands cleanly.
Bench: harbour-core/tests/pp.prg 2 errors → 0 for the realistic
`USE ¯o` / `&(expr)` patterns. Remaining parse errors on line 70
are a pathological `_REGULAR_L` list that includes `&a. [2]`
(space between macro's terminating dot and an array index) — the
PP expands it correctly but Five's lexer refuses the expanded
result. That form doesn't occur in real code.
/tmp/test_use_macro.prg — all four patterns (`USE &f`, `USE &f ALIAS
&f`, `USE &f ALIAS &f INDEX &i`, dot-terminated) now compile. FiveSql2
43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Harbour permits keywords (CASE, DO, WHILE, etc.) to be used as
variable/array names. In most expression contexts Five already
handles this via expr.go:362 which whitelists keywords when used
as bare identifiers. But parseStmtBlock was stopping on any stop
token unconditionally, so a line like
case[ n ] := x -- 'case' is a LOCAL array
terminated the enclosing stmt block at `case` and left `[ n ] := x`
unparsable.
Add isIdentSuffix(): peeks one ahead and reports whether the next
token is something that can only follow an identifier ([, :=, +=,
-=, *=, /=, %=, ^=, ++, --, :, .). parseStmtBlock now treats the
stop token as a statement-start when its suffix matches, so the
block keeps going.
Verified with /tmp/test_kwident.prg (`case[...]` outside DO CASE,
`arr[...]` inside DO CASE body), /tmp/test_kwident2.prg (both the
`case case[n] == "two"` arm and `case[1] := "updated"` assignment
after ENDCASE). Pathological harbour-core/tests/keywords.prg still
fails — it places `case[...]` in the arm-expected position of a
DO CASE block with no leading arm, which no sane parser can
disambiguate.
FiveSql2 43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Classic Clipper/Harbour form writes method implementations as bare
`METHOD Name(params)` statements following a `CLASS X ... ENDCLASS`
declaration, with the binding inferred from the most recent class:
CREATE CLASS Shape
METHOD Area
ENDCLASS
METHOD Area -- binds to Shape
RETURN 0
Five was requiring `METHOD Area CLASS Shape` explicitly. Without it,
parseMethodDecl left MethodDecl.ClassName empty, gengo skipped the
body emission, and the link step failed with `undefined: HB_SHAPE_AREA`.
The class registration had AddMethod("AREA", HB_SHAPE_AREA) pointing
at the missing symbol.
Parser tracks p.lastClassName at parseClassDecl, and parseMethodDecl
falls back to that value when no CLASS clause is supplied. Each new
CLASS declaration updates the tracker, so multi-class files still
dispatch correctly — verified with /tmp/test_implicit_class.prg
(Shape + Box both resolve their own Name/Area methods).
Unblocks harbour-core/tests/clsscope.prg and other OOP compat
tests that use this form. FiveSql2 43/43, Harbour compat 56/56,
Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Harbour's `DATA name1, name2, name3` (and `VAR`, `CLASSDATA`)
should declare every listed field. Five's parseDataDecl instead
returned a single DataDecl for the first name and silently dropped
the rest — the comma branch just consumed the identifier without
producing a new decl. Surfaced by the OPERATOR overloading test
(/tmp/test_operator.prg originally had `DATA x, y` for a Vec2
class) where later `::y` access panicked with "unknown method y".
Change the signature to `[]*ast.DataDecl` and rewrite the loop so
each comma closes the current decl and starts a fresh one. AS /
INIT / qualifier runs still attach to the most recent name, so:
DATA x, y, z → three decls, no init
DATA x INIT 10, y, z INIT 0 → init attaches to preceding name
DATA cName AS CHARACTER → typed single decl
All seven class-body call sites flatten the slice into `members`.
Verified with /tmp/test_multidata.prg (`DATA x, y, z` + mixed
`DATA label INIT "origin", count INIT 0`) and the OPERATOR test
which now passes with the original `DATA x, y` form restored.
FiveSql2 43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Harbour lets a class define custom behaviour for arithmetic and
comparison operators via `OPERATOR "<sym>" ARG <name> INLINE <expr>`.
Five already had the runtime slot infrastructure (ClassDef.Operators
+ AddOperator + parent-chain copy) but parser skipped the form and
the VM ops never consulted the slots.
Parser: parseOperatorDecl captures the symbol, ARG binding, and
INLINE body into a MethodDecl with IsOperator=true and OperatorOp
set to the hbrt.Op* slot. Synthesised method name is __OP_<idx>
to keep the regular method namespace clean.
Codegen: emitClassDecl routes IsOperator members through
_def.AddOperator instead of AddMethod. Inline body generation is
shared with the MESSAGE/INLINE path (34485cd).
VM: Thread.tryBinaryOp walks the LHS object's class operator slot,
pushes args with Self bound to LHS, and returns true if the slot
is populated. Wired into Plus/Minus/Mult/Divide and Equal/NotEqual/
Less/Greater/LessEqual/GreaterEqual. Falls through to built-in
behaviour when no overload exists — non-object LHS costs one tag
check per op.
Operator symbol→slot mapping keeps `=` and `==` on the same slot
(OpEqual=8) because Five's gengo routes both to t.Equal() and the
VM doesn't distinguish strict vs non-strict equality today.
Tested (/tmp/test_operator.prg): Vec2 + - == < with per-field
results all correct.
FiveSql2 43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Harbour's inline-method sugar was parsed but the body was skipped,
leaving any `METHOD X() INLINE expr` declaration registered in the
class vtable with no matching HB_<CLASS>_X function — link error
at build time.
Parser: MethodDecl gains an InlineBody Expr field. parseClassMethodDecl
captures the expression after INLINE instead of skipping to EOL.
New parseMessageDecl handles `MESSAGE <name> [(params)] INLINE expr`
and returns the same MethodDecl shape.
Codegen: emitClassDecl walks members a second time after the class
registration init block and emits emitInlineMethodBody for each
IsInline method — a Frame(nParams, 0) + emitExpr(InlineBody) +
RetValue function. curMethodClass is bound so ::super: inside an
inline body still resolves.
Tested (/tmp/test_inline.prg): all four patterns — bare INLINE,
MESSAGE INLINE, INLINE with params, INLINE reading ::field —
produce expected values.
FiveSql2 43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
All 3 remaining known constraints resolved. CLAUDE.md now shows zero.
1. CDX compound index WRITE support (was read-only)
New file: hbrdd/cdx/build.go (~400 LOC)
- CreateOrAddTag() builds Harbour-compatible CDX files
- Bit-packed leaf pages (RecBits/DupBits/TrlBits compression)
- Interior nodes with big-endian RecNo/ChildPage
- Compound root directory (structural B-tree of tag names)
- Append-safe: preserves existing tags when adding new ones
- Linked leaf pages (LeftPtr/RightPtr for sequential scan)
Pipeline: INDEX ON expr TAG tagname TO file
- ast.IndexCmd gains TagName field
- Parser captures TAG name (was discarded)
- gengo passes TagName to OrderCreateParams
- indexer.go routes to cdx.CreateOrAddTag when TAG specified
Verified: 3 tags (BYNAME/BYCITY/BYAGE), OrdSetFocus by name,
SEEK, GoTop/GoBottom, close+reopen with SET INDEX TO
2. {||} empty code block parsing in function arguments
Parser's parseArrayOrBlock() called parseExpr() unconditionally
after closing |, failing when body was empty ({||}).
Fix: check for RBRACE after closing | and emit NIL literal body.
{=>} empty hash already worked.
3. Semicolon IF...ENDIF — already worked (removed from constraints)
Tests:
go test ./... 14 packages ALL PASS
FiveSql2 43/43 100%
compat_harbour 51/51
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Release-blocking compatibility issues discovered during the 258-test
pre-release validation suite (100 syntax + 44 RDD + 114 RTL).
1. PCount() always returned 0 in PRG code
Root cause: ParamCount() returned t.pendingParams, which is
overwritten by every nested Function() call. By the time the
PCount() RTL's Frame() executes, pendingParams is already 0.
Fix: Frame() now stores pendingParams in frame.paramCount.
PCount() RTL uses CallerParamCount() which reads callSP-2
(the PRG caller's frame), while RTL functions still use
ParamCount() (reads pendingParams before their own Frame).
Verified: PCount(1,2,3)=3, PCount(1)=1, PCount()=0
2. Break("string") panicked instead of being caught by RECOVER USING
Root cause: Generated SEQUENCE code only caught *HbError panics.
Break() panics with BreakValue (a different type), which fell
through to EndProc's "runtime error" message and re-panic.
Fix (two parts):
a) gengo emitBeginSequence: recover closure now catches any
panic (interface{}), then dispatches via type switch:
- *HbError → extract .Error() string
- hasValue interface (BreakValue) → extract .GetValue()
- other → static "error" string
b) hbrtl/error.go: BreakValue gets GetValue() method for
duck-type detection without import cycles
c) hbrt/thread.go EndProc: BreakValue type name check added
so it re-panics silently (no stderr noise)
3. SET INDEX TO a, b, c only opened the last file
Root cause: Parser's parseSet() called parseExpr() once for
INDEX setting, stopping at the first comma. Remaining file
names were consumed by the "eat rest of line" loop.
Fix: Parser now collects comma-separated identifiers into a
single string literal "a,b,c". gengo splits on comma and
calls OrderListAdd() for each file.
Verified: SET INDEX TO si_name, si_city → OrdCount=2
All tests pass:
go test ./... 14 packages OK
FiveSql2 43/43 100%
compat_harbour 51/51
Syntax test 100/100
RDD test 44/44
RTL test 114/114
Windows cross-compile OK
Linux cross-compile OK
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
- skipFilter: skip deleted records in GoTop/GoBottom/Skip when SET DELETED ON
- hbrdd.IsSetDeleted callback: avoids circular import hbrdd→hbrtl
- Parser: capture ON/OFF for boolean SET commands (DELETED, EXACT, SOFTSEEK, etc.)
- Parser: capture TO expr for SET DATE/DECIMALS/EPOCH
- Gengo: emit proper t.Do() calls for 11 SET toggles + 3 value SETs
- stmtSet: was stub (skipToEOL), now calls parseSet()
- RTL: register 11 SET toggle functions (SETDELETED, SETEXACT, etc.)
- RTL: DBLOCATE/DBCONTINUE for sequential search
- RTL: DBSETFILTER/DBCLEARFILTER/DBFILTER
- PadL/PadR: support 3rd param fill character
- Area interface: added SetFound, SetLocate, LocateBlock, filter methods
- MemRDD: implements new Area interface methods
- Comprehensive PRG test: test_search.prg (7 test suites all pass)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
