[ivy]<Satterthwaite>Mimosa>Literals.mesa!5

Literals.mesa
Copyright © 1985 by Xerox Corporation. All rights reserved.
Satterthwaite, June 25, 1986 9:34:11 am PDT
Russ Atkinson (RRA) January 31, 1985 1:02:07 pm PST
DIRECTORY
Symbols: TYPE USING [Type],
Table: TYPE USING [Base, Finger, IndexRep, Selector, Tag],
Target: TYPE MachineParms USING [bitsPerByte];
Literals: DEFINITIONS = {
Base: TYPE = Table.Base;
Finger: TYPE = Table.Finger;
tag codes (0-2 reserved)
ltTag: Table.Tag = 3;
stTag: Table.Tag = 4;
literal constants
Byte: TYPE = [0..256);-- limited to 8-bit bytes (source and target) for now
byteCheck: BOOL[TRUE .. Target.bitsPerByte=8] = TRUE;
ByteSequence: TYPE = PACKED ARRAY [0..0) OF Byte;
LTRecord: TYPE = RECORD[
link: LTIndex,
datum: SELECT kind: * FROM
short => [value: CARD],-- numeric unsigned, but may represent 2's complement signed
long => [
codeIndex: [0..CARDINAL.LAST/2],
length: CARDINAL,
value: ByteSequence]
ENDCASE];
LTIndex: TYPE = Base RELATIVE LONG POINTER TO LTRecord;
LTFirst: LTIndex = LOOPHOLE[Table.IndexRep[tag: ltTag, highBits:0, lowBits:0]];
LTLast: LTIndex = LOOPHOLE[Table.IndexRep[tag: ltTag]];
LTNull: LTIndex = LTLast;
LTId: TYPE = RECORD [baseP: Finger, index: LTIndex];
LitDescriptor: TYPE = RECORD[
offset: Base RELATIVE LONG POINTER TO ByteSequence,
length: CARDINAL];
string literals
STRecord: TYPE = RECORD[
SELECT kind: * FROM
master => [
link: MSTIndex,
local: BOOL,
info: CARDINAL,
codeIndex: CARDINAL,
string: StringBody],
the actual string text follows here
copy => [
mark: BOOL,
link: MSTIndex],
heap => [
link: MSTIndex,
type: Symbols.Type,
info: CARDINAL]
ENDCASE];
STIndex: TYPE = Base RELATIVE LONG POINTER TO STRecord;
STFirst: STIndex = LOOPHOLE[Table.IndexRep[tag: stTag, highBits:0, lowBits:0]];
STLast: STIndex = LOOPHOLE[Table.IndexRep[tag: stTag]];
STNull: STIndex = STLast;
MSTIndex: TYPE = Base RELATIVE LONG POINTER TO STRecord.master;
table allocation codes
ltType: Table.Selector = 7;
stType: Table.Selector = 8;
}.