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kallentukallentu
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Format record pattern. (#1371)
* Format record pattern. * Add an extra switch case. * Remove unnecessary parameter. * Change switch cases to write out the edge cases instead. * Fix comments and revert switch.
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5 files changed

+260
-13
lines changed

5 files changed

+260
-13
lines changed

‎lib/src/ast_extensions.dart

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Original file line numberDiff line numberDiff line change
@@ -392,6 +392,8 @@ extension PatternExtensions on DartPattern {
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elements.canSplit(rightBracket),
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MapPattern(:var elements, :var rightBracket) =>
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elements.canSplit(rightBracket),
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RecordPattern(:var fields, :var rightParenthesis) =>
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fields.canSplit(rightParenthesis),
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_ => false,
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};
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}

‎lib/src/front_end/ast_node_visitor.dart

Lines changed: 19 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -1355,7 +1355,19 @@ class AstNodeVisitor extends ThrowingAstVisitor<Piece> with PieceFactory {
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13561356
@override
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Piece visitPatternField(PatternField node) {
1358-
throw UnimplementedError();
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return buildPiece((b) {
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b.visit(node.name);
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b.visit(node.pattern);
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});
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}
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@override
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Piece visitPatternFieldName(PatternFieldName node) {
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return buildPiece((b) {
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b.token(node.name);
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b.token(node.colon);
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if (node.name != null) b.space();
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});
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}
13601372

13611373
@override
@@ -1424,27 +1436,21 @@ class AstNodeVisitor extends ThrowingAstVisitor<Piece> with PieceFactory {
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@override
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Piece visitRecordLiteral(RecordLiteral node) {
1427-
ListStyle style;
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if (node.fields.length == 1 && node.fields[0] is! NamedExpression) {
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// Single-element records always have a trailing comma, unless the single
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// element is a named field.
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style = const ListStyle(commas: Commas.alwaysTrailing);
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} else {
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style = const ListStyle(commas: Commas.trailing);
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}
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return createCollection(
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return createRecord(
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constKeyword: node.constKeyword,
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node.leftParenthesis,
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node.fields,
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node.rightParenthesis,
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style: style,
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);
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}
14441446

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@override
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Piece visitRecordPattern(RecordPattern node) {
1447-
throw UnimplementedError();
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return createRecord(
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node.leftParenthesis,
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node.fields,
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node.rightParenthesis,
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);
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}
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@override

‎lib/src/front_end/piece_factory.dart

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Original file line numberDiff line numberDiff line change
@@ -702,6 +702,53 @@ mixin PieceFactory {
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);
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}
704704

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/// Creates a [ListPiece] for a record literal or pattern.
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Piece createRecord(
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Token leftParenthesis,
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List<AstNode> fields,
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Token rightParenthesis, {
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Token? constKeyword,
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}) {
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var style = switch (fields) {
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// Record types or patterns with a single named field don't add a trailing
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// comma unless it's split, like:
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//
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// ({int n}) x;
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//
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// Or:
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//
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// if (obj case (name: value)) {
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// ;
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// }
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[PatternField(name: _?)] => const ListStyle(commas: Commas.trailing),
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[NamedExpression()] => const ListStyle(commas: Commas.trailing),
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// Record types or patterns with a single positional field always have a
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// trailing comma to disambiguate from parenthesized expressions or
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// patterns, like:
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//
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// (int,) x;
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//
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// Or:
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//
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// if (obj case (pattern,)) {
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// ;
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// }
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[_] => const ListStyle(commas: Commas.alwaysTrailing),
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// Record types or patterns with multiple fields have regular trailing
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// commas when split.
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_ => const ListStyle(commas: Commas.trailing)
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};
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return createCollection(
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constKeyword: constKeyword,
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leftParenthesis,
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fields,
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rightParenthesis,
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style: style,
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);
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}
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/// Creates a class, enum, extension, mixin, or mixin application class
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/// declaration.
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///

‎test/pattern/record.stmt

Lines changed: 166 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,166 @@
1+
40 columns |
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>>> Basic record switch.
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switch (obj) {
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case ( ) :
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case ( value , ) :
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case ( : var x , ) :
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case ( name : var x , ) :
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case ( first , second , third ) :
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case ( first : 1 , 2 , third : 3 ) :
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case ( : var x , : var y ) :
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ok;
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}
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<<<
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switch (obj) {
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case ():
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case (value,):
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case (:var x):
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case (name: var x):
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case (first, second, third):
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case (first: 1, 2, third: 3):
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case (:var x, :var y):
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ok;
23+
}
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>>> Unsplit single-element record, with trailing comma.
25+
if (obj case (pattern,)) {;}
26+
<<<
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if (obj case (pattern,)) {
28+
;
29+
}
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>>> Remove trailing comma from single named field.
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if (obj case (name: value,)) {;}
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<<<
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if (obj case (name: value)) {
34+
;
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}
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>>> Split single-element record after ",".
37+
if (obj case (veryLongRecordField____________,)) {;}
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<<<
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if (obj case (
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veryLongRecordField____________,
41+
)) {
42+
;
43+
}
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>>> Split single-element named record.
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if (obj case (longFieldName: longRecordFieldValue)) {;}
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<<<
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if (obj case (
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longFieldName: longRecordFieldValue,
49+
)) {
50+
;
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}
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>>> Split single-element named record at name.
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if (obj case (longFieldName: veryLongRecordFieldValue)) {;}
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<<<
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if (obj case (
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longFieldName: veryLongRecordFieldValue,
57+
)) {
58+
;
59+
}
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>>> Split single-element record with inferred name.
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if (obj case (:var veryLongInferredFieldName_____)) {;}
62+
<<<
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if (obj case (
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:var veryLongInferredFieldName_____,
65+
)) {
66+
;
67+
}
68+
>>> Split multiple-element record with inferred names.
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if (obj case (:var firstLongInferredFieldName, :var secondLongInferredName)) {;}
70+
<<<
71+
if (obj case (
72+
:var firstLongInferredFieldName,
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:var secondLongInferredName,
74+
)) {
75+
;
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}
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>>> Don't split between name and list subpattern.
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if (obj case (longFieldName: [first, second, third])) {;}
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<<<
80+
if (obj case (
81+
longFieldName: [first, second, third],
82+
)) {
83+
;
84+
}
85+
>>> Don't split between name and map subpattern.
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if (obj case (longFieldName: {first: 1, second: 2})) {;}
87+
<<<
88+
if (obj case (
89+
longFieldName: {first: 1, second: 2},
90+
)) {
91+
;
92+
}
93+
>>> Don't split between name and record subpattern.
94+
if (obj case (longFieldName: (first: 1, second: 2))) {;}
95+
<<<
96+
if (obj case (
97+
longFieldName: (first: 1, second: 2),
98+
)) {
99+
;
100+
}
101+
>>> If any field splits, all fields split.
102+
if (obj case (first, second, third, fourth, fifth)) {;}
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<<<
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if (obj case (
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first,
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second,
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third,
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fourth,
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fifth,
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)) {
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;
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}
113+
>>> Don't force outer record to split.
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if (obj case ((a,), (b, c))) {;}
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<<<
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if (obj case ((a,), (b, c))) {
117+
;
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}
119+
>>> Split nested record.
120+
if (obj case (first, (second, third, fourth), fifth, (sixth, seventh, eighth, nine, tenth,
121+
eleventh))) {;}
122+
<<<
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if (obj case (
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first,
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(second, third, fourth),
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fifth,
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(
128+
sixth,
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seventh,
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eighth,
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nine,
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tenth,
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eleventh,
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),
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)) {
136+
;
137+
}
138+
>>> Tall splitting style with line comment.
139+
if (obj case (
140+
// yeah
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a,b,c,
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d,e,f,
143+
)) {;}
144+
<<<
145+
if (obj case (
146+
// yeah
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a,
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b,
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c,
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d,
151+
e,
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f,
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)) {
154+
;
155+
}
156+
>>> Remove comma from multiple-field record pattern if unsplit
157+
if (e case (a, b,)) {}
158+
<<<
159+
if (e case (a, b)) {}
160+
>>> Add comma to record pattern if split.
161+
if (e case (longPattern1, veryLongPattern2)) {}
162+
<<<
163+
if (e case (
164+
longPattern1,
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veryLongPattern2,
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)) {}

‎test/pattern/record_comment.stmt

Lines changed: 26 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,26 @@
1+
40 columns |
2+
>>> Empty record pattern block comment.
3+
if (obj case ( /* comment */ )) {;}
4+
<<<
5+
if (obj case (/* comment */)) {
6+
;
7+
}
8+
>>> Empty record pattern line comment.
9+
if (obj case ( // comment
10+
)) {;}
11+
<<<
12+
if (obj case (
13+
// comment
14+
)) {
15+
;
16+
}
17+
>>> Record line comment between fields.
18+
if (obj case ( first , // comment
19+
second)){;}
20+
<<<
21+
if (obj case (
22+
first, // comment
23+
second,
24+
)) {
25+
;
26+
}

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