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Simplifying parsing optional semicolons/commas

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This commit is contained in:
Alexander Luzgarev 2018-04-07 15:22:02 +02:00
parent 5e7a4840b5
commit 51a0cc863f
3 changed files with 50 additions and 57 deletions
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80
Parser/MParser.cs
View File

@ -676,15 +676,34 @@ namespace Parser
return lhs;
}
private SwitchCaseNode ParseSwitchCase()
private List<TokenNode> ParseOptionalCommas()
{
var caseKeyword = EatIdentifier("case");
var caseId = ParseExpression();
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma)
{
commas.Add(Factory.Token(EatToken()));
}
return commas;
}
private List<TokenNode> ParseOptionalSemicolonsOrCommas()
{
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma
|| CurrentToken.Kind == TokenKind.Semicolon)
{
commas.Add(Factory.Token(EatToken()));
}
return commas;
}
private SwitchCaseNode ParseSwitchCase()
{
var caseKeyword = EatIdentifier("case");
var caseId = ParseExpression();
var commas = ParseOptionalCommas();
var statementList = ParseStatements();
return Factory.SwitchCase(Factory.Token(caseKeyword), caseId, statementList, commas);
}
@ -693,11 +712,7 @@ namespace Parser
{
var switchKeyword = EatIdentifier("switch");
var expression = ParseExpression();
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma)
{
commas.Add(Factory.Token(EatToken()));
}
var commas = ParseOptionalCommas();
var casesList = new List<SwitchCaseNode>();
while (CurrentToken.Kind == TokenKind.Identifier
&& CurrentToken.PureToken.LiteralText == "case")
@ -717,46 +732,30 @@ namespace Parser
public ExpressionStatementNode ParseExpressionStatement()
{
var statement = ParseExpression();
if (CurrentToken.Kind == TokenKind.Semicolon)
{
var semicolon = EatToken();
return Factory.ExpressionStatement(statement, Factory.Token(semicolon));
}
return Factory.ExpressionStatement(statement);
var possibleSemicolonOrComma = PossibleSemicolonOrComma();
return Factory.ExpressionStatement(statement, possibleSemicolonOrComma);
}
public WhileStatementNode ParseWhileStatement()
{
var whileKeyword = EatToken();
var condition = ParseExpression();
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma)
{
commas.Add(Factory.Token(EatToken()));
}
var commas = ParseOptionalCommas();
var body = ParseStatements();
var endKeyword = EatIdentifier("end");
var semicolonOrComma = PossibleSemicolonOrComma();
return Factory.WhileStatement(
Factory.Token(whileKeyword),
condition,
commas,
body,
Factory.Token(endKeyword),
commas);
semicolonOrComma);
}
public StatementNode ParseStatement()
{
var statement = ParseStatementCore();
if (statement != null)
{
if (CurrentToken.Kind == TokenKind.Semicolon
|| CurrentToken.Kind == TokenKind.Comma)
{
statement = Factory.AppendSemicolonOrComma(statement, Factory.Token(EatToken()));
}
}
return statement;
}
@ -764,12 +763,7 @@ namespace Parser
{
var ifKeyword = Factory.Token(EatToken());
var condition = ParseExpression();
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma
|| CurrentToken.Kind == TokenKind.Semicolon)
{
commas.Add(Factory.Token(EatToken()));
}
var commas = ParseOptionalSemicolonsOrCommas();
var body = ParseStatements();
TokenNode elseKeyword = null;
StatementListNode elseBody = null;
@ -788,22 +782,25 @@ namespace Parser
return Factory.IfStatement(
ifKeyword,
condition,
commas,
body,
null,
elseBody,
null,
commas);
null);
}
var endKeyword = Factory.Token(EatIdentifier("end"));
var possibleSemicolonOrComma = PossibleSemicolonOrComma();
return Factory.IfStatement(
ifKeyword,
condition,
commas,
body,
elseKeyword,
elseBody,
endKeyword,
commas);
possibleSemicolonOrComma);
}
public ForStatementNode ParseForStatement()
@ -816,12 +813,7 @@ namespace Parser
}
var forAssignment = (AssignmentExpressionNode) expression;
var commas = new List<TokenNode>();
while (CurrentToken.Kind == TokenKind.Comma
|| CurrentToken.Kind == TokenKind.Semicolon)
{
commas.Add(Factory.Token(EatToken()));
}
var commas = ParseOptionalSemicolonsOrCommas();
var body = ParseStatements();
var endKeyword = Factory.Token(EatIdentifier("end"));

22
Parser/SyntaxFactory.cs
View File

@ -219,16 +219,13 @@ namespace Parser
return new UnquotedStringLiteralNode(stringLiteral);
}
public ExpressionStatementNode ExpressionStatement(ExpressionNode expression)
{
var children = new List<SyntaxNode> {expression};
return new ExpressionStatementNode(children, expression, null);
}
public ExpressionStatementNode ExpressionStatement(ExpressionNode expression, TokenNode semicolonOrComma)
{
var children = new List<SyntaxNode> {expression, semicolonOrComma};
return new ExpressionStatementNode(children, expression, semicolonOrComma);
return new ExpressionStatementNode(
RemoveNulls(children),
expression,
semicolonOrComma);
}
public CellArrayElementAccessExpressionNode CellArrayElementAccessExpression(
@ -356,10 +353,10 @@ namespace Parser
public WhileStatementNode WhileStatement(
TokenNode whileKeyword,
ExpressionNode condition,
List<TokenNode> optionalCommasAfterCondition,
StatementListNode body,
TokenNode end,
List<TokenNode> optionalCommasAfterCondition = null,
TokenNode semicolonOrComma = null)
TokenNode semicolonOrComma)
{
var children = new List<SyntaxNode>
{
@ -391,11 +388,12 @@ namespace Parser
public IfStatementNode IfStatement(
TokenNode ifKeyword,
ExpressionNode condition,
List<TokenNode> optionalCommasAfterCondition,
StatementListNode body,
TokenNode elseKeyword,
StatementListNode elseBody,
TokenNode endKeyword,
List<TokenNode> optionalCommasAfterCondition = null)
TokenNode possibleSemicolonOrComma)
{
var children = new List<SyntaxNode>
{
@ -407,6 +405,7 @@ namespace Parser
children.Add(elseKeyword);
children.Add(elseBody);
children.Add(endKeyword);
children.Add(possibleSemicolonOrComma);
return new IfStatementNode(
RemoveNulls(children),
@ -416,7 +415,8 @@ namespace Parser
body,
elseKeyword,
elseBody,
endKeyword);
endKeyword,
possibleSemicolonOrComma);
}
public ParenthesizedExpressionNode ParenthesizedExpression(

5
Parser/SyntaxNode.cs
View File

@ -572,8 +572,9 @@ namespace Parser
StatementListNode body,
TokenNode elseKeyword,
StatementListNode elseBody,
TokenNode endKeyword
) : base(children)
TokenNode endKeyword,
TokenNode possibleSemicolonOrComma
) : base(children, possibleSemicolonOrComma)
{
IfKeyword = ifKeyword;
Condition = condition;