Pascal News

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if lip=nil then top' .fname:=fip else
begin
repeat lip 1: =lip;
if lip' .name>nam then
begin lip:=l1p' .llink; lleft :=true end
else
begin if lip' .name=nam then again:=true; {name conflict)
lip :=lip' .rlink; lleft: =false;
end;
until l1p=nil;
if Heft then lip1' .llink:=fip else lip1' .rlink:=fip
end:;
fip' .1link:=nll; fip' .rlink:=n11;
if again tben err id (+02, nam) ;
end;
procedure initpos( var ~ p:posi tion);
begin p.lv:=level; p.ad:=O;
lifdef SEGMENTS
p.sg:=O
lendif
end;
procedure inita(fsp:sp; fad:integer);
begin wi tb a do begin
asp:=fsp; packbit:=false; ak:=fixed; pos.ad:=fad; pos.lv:=level;
IUdef SEGMENTS
pos.sg:=O;
'endif
end_ end;
function newip(kl:idclass; n:alpba; idt:sp; nxt:ip):ip;
var p:ip; f:iflagset;
begin f:=[l;
case kl of
types,carrbnd~ {similar structure)
new(p,types);
konst:
beginnew(p,konst);~ p' .value:=O end;
vars:
begin new(p,vars); r :=[used ,assigned]; initpos(p ..... vpos) end;
field:
begin new(p,field); p' .foffset:=O end;
proc,func: {same structurel
begin new(p,proc ,actual); p' .pfkind: =actual;
initpos( p' .pfpos); p' .pfno: =0; p' .parhead: =n11; p' .headlc: =0
end
end;
p' .name:=n; p' .klass:=kl; p' .idtype:=idt; p' .next;=nxt;
p' .1link:=n11; p' .rlink:=nll; p' .iflag:=f; newip:=p
end;
function newsp(sf:structform; sz:integer):sp;
var p:sp; sflag:sflagset;
begin sflag:=[l;
case_sf of
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scalar:
begin new(p,scalar); p .... scalno:=O; p'" .fcanst:=nil end;
subrange:
new( p,subrange);
pointer:
begin new(p,pointer); p·.eltype:=n11 end;
power:
new( P ,power) ;
files:
begin new(p,files); sflag:=[withfilel end;
arrays,earray: {same structurel
new(p,arrays);
records:
new(p,records) ;
variant:
new(p,variant):
tag:
new(p,tag);
~d; ...
P .form:=sf; p .size:=sz; p'" .sflag:=sflag; newsp:=p;
end;
procedure init 1;
var c :char;
begin
!initialize the first name space)
new(top,blck); top·.occur:=blck; top·.nl1nk:=n11; top·.fname:=nll;
level :=0;
{reserved words}
rw[ Ol:='if '; rw[ 1]: =' do 1 ; rw[ 2l:='of ';
rw[ 3l:='to '; rw[ 4 J: =' in I; rw[ 5l:='or ';
rw[ 6]:='end '; rw[ 7l: = ' for ' • rw[ 8l:='nil
,.
rw[ 9]: ='var '; rw[10):='div I; rw[ 11]: = 'mod
,.
rw[12]:='set '; rw[13l: ='and '; rw[ 14l: = 'not
,.
rw[15l:='then ,. rw[ 16l: ='else '; rw[17l:='with ';
rw[ 1 B]: =' case I; rw[19l:='type ,. rw[20]: =' goto t;
rw[21]:='file I; rw[22l:='begin '; rw[23l:='until ';
rw[2ijl:='while ,. rw[25]:='array ,. rw[26]:='const I.
rw[27l:='label '; rw[28J:='r€>peat I; rw[29l: = 'record ,.
rw[30l:='downto '; rw[""; _::='packed , rw[32l:='program '~;
rw(33]: ='function'; r'."i. ]:::' procedur ';
{corresponding symbols)
rsy[ Ol:=ifsy; rsy[ 1]:=dosy; rsy[ 2l: =oj"sy;
rsy[ 3l:=tosy; rsy[ ijl:=insy; rsy[ 5l:=orsy;
rsy[ 6l:=endsy; rsy[ 7l:=forsy; rsy[ 8l: =nilcst;
rsy[ 9l:=varsy; rsy[10l:=divsy; rsy[11l: =modsy;
rsy[12l: =setsy; rsy[13l: =andsy; rsy[14l:=notsy;
rsy[ 15l: =thensy; rsy[ 16l: =elsesy; rsy[17l: =withsy;
rsy[ 18l: =casesy; rsy[ 19l: =typesy; rsy[20l: =gotosy;
rsy[21l: =filesy; rsy[22l: =beginsy; rsy[23l: =untilsy;
rsy[2ij l: =whilesy; rsy[25l: =arraysy; rsy[26l: =cOnstsy;
rsy[271: =labelsy; rsy[28l: =repeatsy; rsy[29l: =recordsy;
rsy[30l: =downtosy; rsy[31l: =packedsy'; r sy[ 32l: =progsy;
rsy[33l: =funcsy; rsy[34l: =procsy;
!indices into rw to find reserved words fast)
frw[Ol:= 0; frw[1l:= 0; frw[2l:= 6; frw[3l:=15; frw[4l:=22;
....
CD
00
....
,.
-0
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