# Scanner (`scanner.txt` 1901 lines, `SCANNER.DEF/MOD`)

Lexer + source window + tiny allocators. All parsers call
`GetSym/Accept/Expect/Test`.

## State

| old | proposed | role |
|---|---|---|
| global2 | `scanOptions` | `0=list, 9=caseSens, 12=noHalt` |
| global3 | `curChar` | `377C`=EOF |
| global5 | `curSym` | token 0..60; `10`=ident |
| global6 | `isLiteral` | after number/string |
| global7 | `cardVal` | integer literal |
| global8/9 | `curNode/identKind` | found node / `0=ident,1=num/str,6=with,7=other` |
| global11 | `tokenBuf[0..128]` | ident/number text + `0C` |
| global12 | `curType` | `CARD/REAL/LONGREAL/...` of literal |
| global13 | `curScopeWalk` | `SymTab.global9` chain |
| global14/17 | `realVal/longVal` | via `Doubles.StrToDouble` |
| global16 | `srcFile` | `Files.ReadBytes/SetPos/Open` |
| global4 | `codeFile` | output of `Compile` |
| global21/22/23 | `codeBuf/codeSize/listing` | `GENZ80` 4K buffer |
| global24 | `charClass[0..255]` | `10`=letter, `11`=digit, `12`=quote ... |
| global25/26 | `tokPos/tokCol` | start of token |
| procPtr27 | `keywordHash` | `(ADR(tokenBuf),case)->CARD` |
| buffer/bufIndex/filePos/column | same | 128B window at `0080H/006CH/006EH/0070H` |
| stackLimit | same | heap guard at `0316H`, `FREEMARKER=3AE3H` |

Pipeline: `OpenSource(proc29) -> InitScan(proc28) -> NextChar(proc2) ->
scanNextToken(proc39) -> GetSym(proc1)` + `Number/SkipComment` helpers.

128B window: `bufIndex=128` = empty; `NextChar` calls `Refill(proc34)`
(`ReadBytes 128`, pad `EOT=032C`), else `buffer[bufIndex++]`,
`INC(filePos)`, echo if `0 IN options` (`EchoChar proc33`).

## Procedures (proposed)

| old | proposed |
|---|---|
| proc1 | `GetSym` |
| proc39 | `ScanNextToken` |
| NUMBER | `ParseNumber` (base `*10/*8/*16`, `.`->real, `D/E` exp, `H/O/C/L` suffix) |
| proc38 | `SkipComment` (nested `(* *)`, `$L+-` toggles options) |
| proc2/34/28/29 | `NextChar/RefillBuffer/InitScan/OpenSource` |
| proc32/33 | `ListPrefix/EchoChar` |
| proc4/8/9/10/11 | `Accept/Expect/TestSet/Test40/Test13` |
| proc12/13/21 | `NeedIdent/ExpectKind/ExpectString` |
| proc3 | `PushWithScope` |
| proc25 | `AddExtension` |
| proc26 | `ScanError` -> `Errors.proc1` |
| proc27 | `EnterSymtabKey` |
| proc7=Allocate | `HeapAlloc` (was Z80) |
| proc5/6 | `GetStackMark/CheckStack` |
| proc22/23/24=`FindIdent/StrCmp/StrLen` | keyword/scope search (were Z80) |
| proc16/15/14 | `CopyString/NewNode/NewSizedNode` |
| proc18/19/20/17 | `MkIdent/DeclIdent/InsertSym/NewScope` |
| proc30=`COMPIL` | `Compile` (top driver) |