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WebFreak001WebFreak001
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separate ASTVisitor.visit for ExpressionNode
abstract classes should not have visitor functions, but rather only do dynamic dispatch. This becomes more important later with #409
1 parent 2490a81 commit 776ca6b

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2 files changed

+67
-42
lines changed

2 files changed

+67
-42
lines changed

‎src/dparse/ast.d‎

Lines changed: 29 additions & 4 deletions
Original file line numberDiff line numberDiff line change
@@ -92,11 +92,32 @@ enum DeclarationListStyle : ubyte
9292
*/
9393
abstract class ASTVisitor
9494
{
95-
96-
/** */
95+
deprecated("Don't use or override visit(ExpressionNode). For usage: dynamicDispatch(ExpressionNode) is equivalent; "
96+
~ "for overriding: you should probably override more specific cases. If you need to override to inject some "
97+
~ "before/after code for all cases, make sure to call `super.dynamicDispatch(n)` instead of `n.accept(this)`!")
9798
void visit(const ExpressionNode n)
9899
{
99-
switch (typeMap[typeid(n)])
100+
dynamicDispatch(n);
101+
}
102+
103+
/**
104+
* Looks at the runtime type of `n`, then calls the appropriate `visit`
105+
* method at runtime.
106+
*
107+
* Rule of thumb: when the type is an abstract class, use `dynamicDispatch`,
108+
* otherwise use `visit`.
109+
*
110+
* For templated calls:
111+
* ---
112+
* static if (__traits(isAbstractClass, typeof(node)))
113+
* visitor.dynamicDispatch(node);
114+
* else
115+
* visitor.visit(node);
116+
* ---
117+
*/
118+
void dynamicDispatch(const ExpressionNode n)
119+
{
120+
switch (typeMap.get(typeid(n), 0))
100121
{
101122
case 1: visit(cast(AddExpression) n); break;
102123
case 2: visit(cast(AndAndExpression) n); break;
@@ -383,11 +404,15 @@ template visitIfNotNull(fields ...)
383404
{
384405
static if (typeof(fields[0]).stringof[$ - 2 .. $] == "[]")
385406
{
386-
static if (__traits(hasMember, typeof(fields[0][0]), "classinfo"))
407+
static if (__traits(isAbstractClass, typeof(fields[0][0])))
408+
immutable visitIfNotNull = "foreach (i; " ~ fields[0].stringof ~ ") if (i !is null) visitor.dynamicDispatch(i);\n";
409+
else static if (__traits(hasMember, typeof(fields[0][0]), "classinfo"))
387410
immutable visitIfNotNull = "foreach (i; " ~ fields[0].stringof ~ ") if (i !is null) visitor.visit(i);\n";
388411
else
389412
immutable visitIfNotNull = "foreach (i; " ~ fields[0].stringof ~ ") visitor.visit(i);\n";
390413
}
414+
else static if (__traits(isAbstractClass, typeof(fields[0])))
415+
immutable visitIfNotNull = "if (" ~ fields[0].stringof ~ " !is null) visitor.dynamicDispatch(" ~ fields[0].stringof ~ ");\n";
391416
else static if (__traits(hasMember, typeof(fields[0]), "classinfo"))
392417
immutable visitIfNotNull = "if (" ~ fields[0].stringof ~ " !is null) visitor.visit(" ~ fields[0].stringof ~ ");\n";
393418
else static if (is(Unqual!(typeof(fields[0])) == Token))

‎src/dparse/astprinter.d‎

Lines changed: 38 additions & 38 deletions
Original file line numberDiff line numberDiff line change
@@ -23,12 +23,12 @@ class XMLPrinter : ASTVisitor
2323
{
2424
output.writeln("<addExpression operator=\"", str(addExpression.operator), "\">");
2525
output.writeln("<left>");
26-
visit(addExpression.left);
26+
dynamicDispatch(addExpression.left);
2727
output.writeln("</left>");
2828
if (addExpression.right !is null)
2929
{
3030
output.writeln("<right>");
31-
visit(addExpression.right);
31+
dynamicDispatch(addExpression.right);
3232
output.writeln("</right>");
3333
}
3434
output.writeln("</addExpression>");
@@ -58,12 +58,12 @@ class XMLPrinter : ASTVisitor
5858
{
5959
output.writeln("<andAndExpression>");
6060
output.writeln("<left>");
61-
visit(andAndExpression.left);
61+
dynamicDispatch(andAndExpression.left);
6262
output.writeln("</left>");
6363
if (andAndExpression.right !is null)
6464
{
6565
output.writeln("<right>");
66-
visit(andAndExpression.right);
66+
dynamicDispatch(andAndExpression.right);
6767
output.writeln("</right>");
6868
}
6969
output.writeln("</andAndExpression>");
@@ -73,12 +73,12 @@ class XMLPrinter : ASTVisitor
7373
{
7474
output.writeln("<andExpression>");
7575
output.writeln("<left>");
76-
visit(andExpression.left);
76+
dynamicDispatch(andExpression.left);
7777
output.writeln("</left>");
7878
if (andExpression.right !is null)
7979
{
8080
output.writeln("<right>");
81-
visit(andExpression.right);
81+
dynamicDispatch(andExpression.right);
8282
output.writeln("</right>");
8383
}
8484
output.writeln("</andExpression>");
@@ -191,13 +191,13 @@ class XMLPrinter : ASTVisitor
191191
if (caseRangeStatement.low !is null)
192192
{
193193
output.writeln("<low>");
194-
visit(caseRangeStatement.low);
194+
dynamicDispatch(caseRangeStatement.low);
195195
output.writeln("</low>");
196196
}
197197
if (caseRangeStatement.high !is null)
198198
{
199199
output.writeln("<high>");
200-
visit(caseRangeStatement.high);
200+
dynamicDispatch(caseRangeStatement.high);
201201
output.writeln("</high>");
202202
}
203203
if (caseRangeStatement.declarationsAndStatements !is null)
@@ -295,7 +295,7 @@ class XMLPrinter : ASTVisitor
295295
if (deprecated_.assignExpression !is null)
296296
{
297297
output.writeln("<deprecated>");
298-
visit(deprecated_.assignExpression);
298+
dynamicDispatch(deprecated_.assignExpression);
299299
output.writeln("</deprecated>");
300300
}
301301
else
@@ -320,7 +320,7 @@ class XMLPrinter : ASTVisitor
320320
visit(enumMember.type);
321321
output.write("<name>", enumMember.name.text, "</name>");
322322
if (enumMember.assignExpression !is null)
323-
visit(enumMember.assignExpression);
323+
dynamicDispatch(enumMember.assignExpression);
324324
output.writeln("</anonymousEnumMember>");
325325
}
326326

@@ -336,10 +336,10 @@ class XMLPrinter : ASTVisitor
336336
{
337337
output.writeln("<equalExpression operator=\"", str(equalExpression.operator), "\">");
338338
output.writeln("<left>");
339-
visit(equalExpression.left);
339+
dynamicDispatch(equalExpression.left);
340340
output.writeln("</left>");
341341
output.writeln("<right>");
342-
visit(equalExpression.right);
342+
dynamicDispatch(equalExpression.right);
343343
output.writeln("</right>");
344344
output.writeln("</equalExpression>");
345345
}
@@ -475,10 +475,10 @@ class XMLPrinter : ASTVisitor
475475
else
476476
output.writeln("<identityExpression operator=\"is\">");
477477
output.writeln("<left>");
478-
visit(identityExpression.left);
478+
dynamicDispatch(identityExpression.left);
479479
output.writeln("</left>");
480480
output.writeln("<right>");
481-
visit(identityExpression.right);
481+
dynamicDispatch(identityExpression.right);
482482
output.writeln("</right>");
483483
output.writeln("</identityExpression>");
484484
}
@@ -541,10 +541,10 @@ class XMLPrinter : ASTVisitor
541541
else
542542
output.writeln("<inExpression operator=\"in\">");
543543
output.writeln("<left>");
544-
visit(inExpression.left);
544+
dynamicDispatch(inExpression.left);
545545
output.writeln("</left>");
546546
output.writeln("<right>");
547-
visit(inExpression.right);
547+
dynamicDispatch(inExpression.right);
548548
output.writeln("</right>");
549549
output.writeln("</inExpression>");
550550
}
@@ -613,10 +613,10 @@ class XMLPrinter : ASTVisitor
613613
{
614614
output.writeln("<keyValuePair>");
615615
output.writeln("<key>");
616-
visit(keyValuePair.key);
616+
dynamicDispatch(keyValuePair.key);
617617
output.writeln("</key>");
618618
output.writeln("<value>");
619-
visit(keyValuePair.value);
619+
dynamicDispatch(keyValuePair.value);
620620
output.writeln("</value>");
621621
output.writeln("</keyValuePair>");
622622
}
@@ -676,12 +676,12 @@ class XMLPrinter : ASTVisitor
676676
{
677677
output.writeln("<mulExpression operator=\"", str(mulExpression.operator), "\">");
678678
output.writeln("<left>");
679-
visit(mulExpression.left);
679+
dynamicDispatch(mulExpression.left);
680680
output.writeln("</left>");
681681
if (mulExpression.right !is null)
682682
{
683683
output.writeln("<right>");
684-
visit(mulExpression.right);
684+
dynamicDispatch(mulExpression.right);
685685
output.writeln("</right>");
686686
}
687687
output.writeln("</mulExpression>");
@@ -691,12 +691,12 @@ class XMLPrinter : ASTVisitor
691691
{
692692
output.writeln("<orOrExpression>");
693693
output.writeln("<left>");
694-
visit(orOrExpression.left);
694+
dynamicDispatch(orOrExpression.left);
695695
output.writeln("</left>");
696696
if (orOrExpression.right !is null)
697697
{
698698
output.writeln("<right>");
699-
visit(orOrExpression.right);
699+
dynamicDispatch(orOrExpression.right);
700700
output.writeln("</right>");
701701
}
702702
output.writeln("</orOrExpression>");
@@ -727,12 +727,12 @@ class XMLPrinter : ASTVisitor
727727
{
728728
output.writeln("<powExpression>");
729729
output.writeln("<left>");
730-
visit(powExpression.left);
730+
dynamicDispatch(powExpression.left);
731731
output.writeln("</left>");
732732
if (powExpression.right !is null)
733733
{
734734
output.writeln("<right>");
735-
visit(powExpression.right);
735+
dynamicDispatch(powExpression.right);
736736
output.writeln("</right>");
737737
}
738738
output.writeln("</powExpression>");
@@ -743,10 +743,10 @@ class XMLPrinter : ASTVisitor
743743
output.writeln("<relExpression operator=\"",
744744
xmlAttributeEscape(str(relExpression.operator)), "\">");
745745
output.writeln("<left>");
746-
visit(relExpression.left);
746+
dynamicDispatch(relExpression.left);
747747
output.writeln("</left>");
748748
output.writeln("<right>");
749-
visit(relExpression.right);
749+
dynamicDispatch(relExpression.right);
750750
output.writeln("</right>");
751751
output.writeln("</relExpression>");
752752
}
@@ -768,10 +768,10 @@ class XMLPrinter : ASTVisitor
768768
output.writeln("<shiftExpression operator=\"",
769769
xmlAttributeEscape(str(shiftExpression.operator)), "\">");
770770
output.writeln("<left>");
771-
visit(shiftExpression.left);
771+
dynamicDispatch(shiftExpression.left);
772772
output.writeln("</left>");
773773
output.writeln("<right>");
774-
visit(shiftExpression.right);
774+
dynamicDispatch(shiftExpression.right);
775775
output.writeln("</right>");
776776
output.writeln("</shiftExpression>");
777777
}
@@ -804,7 +804,7 @@ class XMLPrinter : ASTVisitor
804804
if (templateAliasParameter.colonExpression !is null)
805805
{
806806
output.writeln("<specialization>");
807-
visit(templateAliasParameter.colonExpression);
807+
dynamicDispatch(templateAliasParameter.colonExpression);
808808
output.writeln("</specialization>");
809809
}
810810
else if (templateAliasParameter.colonType !is null)
@@ -817,7 +817,7 @@ class XMLPrinter : ASTVisitor
817817
if (templateAliasParameter.assignExpression !is null)
818818
{
819819
output.writeln("<default>");
820-
visit(templateAliasParameter.assignExpression);
820+
dynamicDispatch(templateAliasParameter.assignExpression);
821821
output.writeln("</default>");
822822
}
823823
else if (templateAliasParameter.assignType !is null)
@@ -962,14 +962,14 @@ class XMLPrinter : ASTVisitor
962962
if (typeSuffix.high !is null)
963963
{
964964
output.writeln("<low>");
965-
visit(typeSuffix.low);
965+
dynamicDispatch(typeSuffix.low);
966966
output.writeln("</low>");
967967
output.writeln("<high>");
968-
visit(typeSuffix.high);
968+
dynamicDispatch(typeSuffix.high);
969969
output.writeln("</high>");
970970
}
971971
else
972-
visit(typeSuffix.low);
972+
dynamicDispatch(typeSuffix.low);
973973
output.writeln("</typeSuffix>");
974974
}
975975
}
@@ -1041,12 +1041,12 @@ class XMLPrinter : ASTVisitor
10411041
{
10421042
output.writeln("<xorExpression>");
10431043
output.writeln("<left>");
1044-
visit(xorExpression.left);
1044+
dynamicDispatch(xorExpression.left);
10451045
output.writeln("</left>");
10461046
if (xorExpression.right !is null)
10471047
{
10481048
output.writeln("<right>");
1049-
visit(xorExpression.right);
1049+
dynamicDispatch(xorExpression.right);
10501050
output.writeln("</right>");
10511051
}
10521052
output.writeln("</xorExpression>");
@@ -1058,15 +1058,15 @@ class XMLPrinter : ASTVisitor
10581058
if (index.high)
10591059
{
10601060
output.writeln("<low>");
1061-
visit(index.low);
1061+
dynamicDispatch(index.low);
10621062
output.writeln("</low>");
10631063

10641064
output.writeln("<high>");
1065-
visit(index.high);
1065+
dynamicDispatch(index.high);
10661066
output.writeln("</high>");
10671067
}
10681068
else
1069-
visit(index.low);
1069+
dynamicDispatch(index.low);
10701070
output.writeln("</index>");
10711071
}
10721072

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