网络上的Dart和Antlr4 -不匹配输入

Question

哇，这是一个非常用词的查询，让我再试一次。

我还在学英语，试着理解语法。我使用的是语法(不是我写的--所以我尽量不调整它，因为它是许多组( 在这里发现的)使用的标准)。

我正在使用它在颤振应用程序中。当我在Linux或Android上运行它时，它没有问题地运行。当我尝试运行它没有网页，我立即有问题。我使用的全部语法如下。

grammar FhirPath;

// Grammar rules [FHIRPath](http://hl7.org/fhirpath/N1) Normative Release

//prog: line (line)*; line: ID ( '(' expr ')') ':' expr '\r'? '\n';
entireExpression: expression EOF;

expression:
    term                                                # termExpression
    | expression '.' invocation                         # invocationExpression
    | expression '[' expression ']'                     # indexerExpression
    | ('+' | '-') expression                            # polarityExpression
    | expression ('*' | '/' | 'div' | 'mod') expression # multiplicativeExpression
    | expression ('+' | '-' | '&') expression           # additiveExpression
    | expression '|' expression                         # unionExpression
    | expression ('<=' | '<' | '>' | '>=') expression   # inequalityExpression
    | expression ('is' | 'as') typeSpecifier            # typeExpression
    | expression ('=' | '~' | '!=' | '!~') expression   # equalityExpression
    | expression ('in' | 'contains') expression         # membershipExpression
    | expression 'and' expression                       # andExpression
    | expression ('or' | 'xor') expression              # orExpression
    | expression 'implies' expression                   # impliesExpression;
//| (IDENTIFIER)? '=>' expression                             #lambdaExpression

term:
    invocation              # invocationTerm
    | literal               # literalTerm
    | externalConstant      # externalConstantTerm
    | '(' expression ')'    # parenthesizedTerm;

literal:
    '{' '}'                 # nullLiteral
    | ('true' | 'false')    # booleanLiteral
    | STRING                # stringLiteral
    | NUMBER                # numberLiteral
    | DATE                  # dateLiteral
    | DATETIME              # dateTimeLiteral
    | TIME                  # timeLiteral
    | quantity              # quantityLiteral;

externalConstant: '%' ( identifier | STRING);

invocation: // Terms that can be used after the function/member invocation '.'
    identifier  # memberInvocation
    | function  # functionInvocation
    | '$this'   # thisInvocation
    | '$index'  # indexInvocation
    | '$total'  # totalInvocation;

function: identifier '(' paramList? ')';

paramList: expression (',' expression)*;

quantity: NUMBER unit?;

unit:
    pluralDateTimePrecision
    | dateTimePrecision
    | STRING; // UCUM syntax for units of measure

pluralDateTimePrecision:
    'years'
    | 'months'
    | 'weeks'
    | 'days'
    | 'hours'
    | 'minutes'
    | 'seconds'
    | 'milliseconds';

dateTimePrecision:
    'year'
    | 'month'
    | 'week'
    | 'day'
    | 'hour'
    | 'minute'
    | 'second'
    | 'millisecond';

typeSpecifier: qualifiedIdentifier;

qualifiedIdentifier: identifier ('.' identifier)*;

identifier:
    IDENTIFIER
    | DELIMITEDIDENTIFIER
    | 'as'
    | 'is'
    | 'contains'
    | 'in'
    | 'div';

/****************************************************************
 Lexical rules ***************************************************************
 */

/*
 NOTE: The goal of these rules in the grammar is to provide a date token to the parser. As such it
 is not attempting to validate that the date is a correct date, that task is for the parser or
 interpreter.
 */

DATE: '@' DATEFORMAT;

DATETIME:
    '@' DATEFORMAT 'T' (TIMEFORMAT TIMEZONEOFFSETFORMAT?)?;

TIME: '@' 'T' TIMEFORMAT;

fragment DATEFORMAT:
    [0-9][0-9][0-9][0-9] ('-' [0-9][0-9] ('-' [0-9][0-9])?)?;

fragment TIMEFORMAT:
    [0-9][0-9] (':' [0-9][0-9] (':' [0-9][0-9] ('.' [0-9]+)?)?)?;

fragment TIMEZONEOFFSETFORMAT: (
        'Z'
        | ('+' | '-') [0-9][0-9]':' [0-9][0-9]
    );

IDENTIFIER: ([A-Za-z] | '_') ([A-Za-z0-9] | '_')*;
// Added _ to support CQL (FHIR could constrain it out)

DELIMITEDIDENTIFIER: '`' (ESC | ~[\\`])* '`';

STRING: '\'' (ESC | ~['])* '\'';

// Also allows leading zeroes now (just like CQL and XSD)
NUMBER: [0-9]+ ('.' [0-9]+)?;

// Pipe whitespace to the HIDDEN channel to support retrieving source text through the parser.
WS: [ \r\n\t]+ -> channel(HIDDEN);

COMMENT: '/*' .*? '*/' -> channel(HIDDEN);

LINE_COMMENT: '//' ~[\r\n]* -> channel(HIDDEN);

fragment ESC:
    '\\' ([`'\\/fnrt] | UNICODE); // allow \`, \', \\, \/, \f, etc. and \uXXX

fragment UNICODE: 'u' HEX HEX HEX HEX;

fragment HEX: [0-9a-fA-F];

我用以下代码生成代码：

antlr4 -Dlanguage=Dart FhirPath.g4 -visitor -no-listener

然后，为了测试，我使用以下代码：

final input = InputStream.fromString('name');
final lexer = FhirPathLexer(input);
final tokens = CommonTokenStream(lexer);
final parser = FhirPathParser(tokens);
parser.buildParseTree = true;
final tree = parser.expression();

如果我在一个简单的省道脚本中运行它，它就会毫无问题地运行。但是，如果我将它放入一个颤振应用程序(同样，只在web上运行，否则它似乎没有问题)，我就会得到以下错误：

line 1:0 mismatched input 'name' expecting {'as', 'in', 'is', 'contains', 'div', 'mod', IDENTIFIER, DELIMITEDIDENTIFIER}

我想我对语法有一些不理解的地方，所以任何见解都是值得赞赏的。

Answer 1

我的结论是，这是一个转到javascript的错误。antlr4版本适用于我对Android和Linux的所有测试，然后抛出大量的web错误。我回到了使用叶柄分析器而不是antlr4。如果其他人有建议的话，请随便留下，但现在，我要结束这个话题。如果您想比较这两个版本的外观，这里有两个版本：路径/库