grammar

问题 I'm trying to implement javascript parser and I stuck in a problem. Javascript has a technique called "semicolon insertion". So what is a common way to deal with automatic semicolon insertion in js parsers? Should I rewrite original grammar to make it be able to deal with auto semicolons? Is it possible? Or should I implement parser for original grammar and then use some tricky technique to deal with semicolons ? All suggestions are welcome. 来源： https://stackoverflow.com/questions/14295850

问题 Scenario : I have 2 commands. 1) Search Google for "any word here" 2) Open application "any word here" Problem : Since the word after "Search Google for" can be anything, how am I suppose to know what am I going to write for my IF statements? With pre-defined sentences, I can do it easily like void Engine_SpeechRecognized (object sender, SpeechRecognizedEventsArgs e) { if (e.Result.Text == "Search Google Stackoverflow") { Search("Stackoverflow"); } } But since now it's not pre-defined, what

问题 I have a problem with transforming parsed JSON-like string, which contains nested arrays, to structured object. I am using parslet to do this. I created parser and transformer, presented below. But I can't handle nested arrays situation. require 'parslet' class JSONLikeDataParser < Parslet::Parser rule(:l_map_paren) {str('{')} rule(:r_map_paren) {str('}')} rule(:l_list_paren) {str('[')} rule(:r_list_paren) {str(']')} rule(:map_entry_delimiter) {str(':')} rule(:val_delimiter) {str(',')} rule(

问题 In Chrome 63.0 and Firefox 58.0, it appears that adding an index to an object literal prevents the object from being parsed as an object. {"a":"b"} 17:37:32.246 {a: "b"} {"a":"b"}["a"] 17:37:36.578 VM288:1 Uncaught SyntaxError: Unexpected token : Can anybody explain why the parser doesn't parse this the way I do? (I think there must be a bug in my implementation of the spec...) It seems to think it's not parsing an object. Surrounding the object in brackets results in syntactically correct

问题 I am trying to parse CSP(Communicating Sequential Processes) CSP Reference Manual. I have defined following grammar rules. assignment : IDENT '=' processExpression ; processExpression : ( STOP | SKIP | chaos | prefix | prefixWithValue | seqComposition | interleaving | externalChoice .... seqComposition : processExpression ';' processExpression ; interleaving : processExpression '|||' processExpression ; externalChoice : processExpression '[]' processExpression ; Now ANTLR reports that

问题 I'm attempting to create a boolean expression language/grammar for a personal project. The user will be able to write a string in a Java-like syntax, with provision for variables, which will be evaluated at a later time when the variables have been initialised. Rain For example, a user might enter the string @FOO+7 > 4*(5+@BAR); Later, when the variable FOO is initialised and equal to 6, and BAR is equal to 1, the expression evaluates to 13>24 and thus returns false. I'm using ANTLRworks to

问题 I'm using Microsoft Speech API to load a grxml grammar: Grammar grammar = new Grammar(file); grammar.Enabled = true; SpeechRecognitionEngine sre = GetEngine(); sre.LoadGrammarAsync(grammar); Based on MSDN I can not find tag to match a wildcard / spoken text like: <item>My message is {dictation}</item> It seems to be availalble with code with a DictationGrammar and appendDictation(). It's also available with WSRMacro XML using * but I do not how to do it in XML ? The skip text but I need to

问题 I'm trying to use a DCG to split a string into two parts separated by spaces. E.g. 'abc def' should give me back "abc" & "def". The program & DCG are below. main:- prompt(_, ''), repeat, read_line_to_codes(current_input, Codes), ( Codes = end_of_file -> true ; processData(Codes), fail ). processData(Codes):- ( phrase(data(Part1, Part2), Codes) -> format('~s, ~s\n', [ Part1, Part2 ]) ; format('Didn''t recognize data.\n') ). data([ P1 | Part1 ], [ P2 | Part2 ]) --> [ P1 | Part1 ], spaces(_), [

问题 The following simple grammar to parse a logical expression results in a reduce/reduce conflict: %token AND OR %token NUMBER VARIABLE %% logical_expr : logical_expr AND logical_term | logical_expr OR logical_term | logical_term ; logical_term : VARIABLE | comparison | '(' logical_expr ')' ; comparison : expr '<' expr | expr '>' expr ; expr : expr '+' term | expr '-' term | term ; term : NUMBER | VARIABLE | '(' expr ')' ; %% The status report from bison has: state 2 4 logical_term: VARIABLE .

问题 I'm new to ANTLR. I just discovered that it is possible to label each alternative in a production like so: foo : a # aLabel | b # bLabel | // ... ; However, I find it unpleasant that all or none alternatives must be labeled. I needed to label just 2 alternatives of a production with 20+ branches recently, and I ended up labelling each of the others # stubLabel . Is there any reason why all or none have to be labeled? 回答1: As soon as you add a label ANTLR4 will no longer generate a context