[_CD8_]<doradomicrocode>MicroD>MDSymbolsImpl.mesa!2

MDSymbolsImpl.mesa

Willie-sue, April 14, 1986 6:48:14 pm PST

taken from MicSym.bcpl and (distantly) MicSA.bcpl

DIRECTORY

Atom USING [MakeAtom],

RefTab USING [EachPairAction, Create, Fetch, Pairs, Ref, Store, Val],

IO,

Rope,

MDDefs,

MDOps USING [],

MDUtils;

MDSymbolsImpl: CEDAR PROGRAM

IMPORTS

Atom, RefTab

EXPORTS

MDOps, MDUtils

= BEGIN OPEN MDDefs;

ROPE: TYPE = Rope.ROPE;

symbolTable: RefTab.Ref;

symbolTableSize: NAT = 2047;

AddSym: PUBLIC PROC[symName: ROPE, addIfNew: BOOL ← TRUE]

RETURNS[symbol: Symbol] = {

found: BOOL;

val: RefTab.Val;

symb: ATOM ← Atom.MakeAtom[symName];

[found, val] ← RefTab.Fetch[symbolTable, symb];

IF found THEN symbol ← NARROW[val];

IF found OR ~addIfNew THEN RETURN[symbol];

symbol ← NEW[SymbolRec ← [atm: symb, name: symName]];

[] ← RefTab.Store[symbolTable, symb, symbol]; -- add to table

};

InitSymbolTable: PUBLIC PROC =

{ symbolTable ← RefTab.Create[symbolTableSize] }; -- easiest

SearchTableProc: TYPE = PROC[sym: MDDefs.Symbol] RETURNS[quit: BOOL];

SearchSymbolTable: PUBLIC PROC[proc: MDUtils.SearchTableProc] = {

LookAt: RefTab.EachPairAction = {

sym: Symbol ← NARROW[val];

quit ← proc[sym];

};

[] ← RefTab.Pairs[symbolTable, LookAt];

};

GS: PROC[symName: ROPE] RETURNS[symbol: Symbol] =

{ RETURN[AddSym[symName, FALSE]] };

END.