antlr 3.0中的错误处理
当用户输入与我们定义的规则不匹配时,我需要报告自定义错误 这是我的密码:antlr 3.0中的错误处理,antlr,Antlr,当用户输入与我们定义的规则不匹配时,我需要报告自定义错误 这是我的密码: grammar second1; @lexer::members { @Override public void reportError(RecognitionException e) { System.out.println("Throwing Exception: "+ e.getMessage()); throw new IllegalArgumentException(e); } } @par
grammar second1;
@lexer::members {
@Override
public void reportError(RecognitionException e) {
System.out.println("Throwing Exception: "+ e.getMessage());
throw new IllegalArgumentException(e);
}
}
@parser::members {
private boolean inbounds(Token t, int min, int max, String methodName) {
int n = Integer.parseInt(t.getText());
if(n >= min && n <= max) {
return true;
}
else {
System.out.println("The range for value accepted by " + methodName+" is "+min +"-" + max );
return false;
}
}
}
expr : SET attribute EOF;
attribute : Value1 int1:integer1["Value1"] { System.out.println("Accepted"); }
| Value2 integer2 ["Value2"] { System.out.println("Accepted"); }
;
exception[int1]:
catch[Exception e] {System.out.println("Error Reported for int1");}
exception:
catch[Exception e] {System.out.println("General error Reported");}
integer1 [String methodName] : Int { inbounds($Int,0,1000,methodName) }? ;
integer2 [String methodName] : Int { inbounds($Int,0,10000,methodName) }? ;
Int : '0'..'9'+;
SET : 'set';
Value1 : 'value';
Value2 : 'value2';
fragment WS
: (' ' | '\t')
;
语法第二;
@lexer::成员{
@凌驾
公共作废报告错误(识别异常e){
System.out.println(“抛出异常:+e.getMessage());
抛出新的IllegalArgumentException(e);
}
}
@解析器::成员{
私有布尔内边界(标记t、最小整数、最大整数、字符串方法名){
int n=Integer.parseInt(t.getText());
如果(n>=min&&n“Catch块不再以'exception'关键字作为前缀”,那么您的属性规则将是:
attribute :
Value1 integer1["Value1"] { System.out.println("Accepted"); }
| Value2 integer2["Value2"] { System.out.println("Accepted"); }
;
catch[Exception e] {System.out.println("General error Reported");}
接下来,您重写了lexer的reportError方法,而不是解析器的方法(调用入站检查)
要使解析器抛出错误而不是恢复,您可以将reportError复制到@parser::members部分,然后您可以得到“常规错误报告”
但是,如果您不想停止antlr的恢复机制,而是想让错误消息更具信息性,您可以免费阅读并定义getErrorMessage方法:
public String getErrorMessage(RecognitionException e, String[] tokenNames)
{
List stack = getRuleInvocationStack(e, this.getClass().getName());
String msg = null;
if ( e instanceof NoViableAltException ) {
NoViableAltException nvae = (NoViableAltException)e;
msg = " no viable alt; token="+e.token+
" (decision="+nvae.decisionNumber+
" state "+nvae.stateNumber+")"+
" decision=<<"+nvae.grammarDecisionDescription+">>";
}
else if( e instanceof FailedPredicateException ) {
FailedPredicateException fpe = (FailedPredicateException)e;
msg = "failed predicate; token="+fpe.token+
" (rule="+fpe.ruleName+" predicate="+fpe.predicateText+")";
}
else {
msg = super.getErrorMessage(e, tokenNames);
}
return stack+" "+msg;
}
public String getTokenErrorDisplay(Token t) {
return t.toString();
}
公共字符串getErrorMessage(识别异常e,字符串[]标记名)
{
列表堆栈=getRuleInvocationStack(即this.getClass().getName());
字符串msg=null;
if(NoViableAltException的实例){
NoviableException nvae=(NoviableException)e;
msg=“没有可行的alt;token=“+e.token+
“(decision=“+nvae.decisionNumber+
“州“+nvae.stateNumber+”)+
“决定”;
}
else if(例如FailedPredicateException的实例){
FailedPredicateException fpe=(FailedPredicateException)e;
msg=“失败的谓词;令牌=“+fpe.token+
“(规则=“+fpe.ruleName+”谓词=“+fpe.predicateText+”);
}
否则{
msg=super.getErrorMessage(e,标记名);
}
返回堆栈+“”+msg;
}
公共字符串getTokenErrorDisplay(令牌t){
返回t.toString();
}
public String getErrorMessage(RecognitionException e, String[] tokenNames)
{
List stack = getRuleInvocationStack(e, this.getClass().getName());
String msg = null;
if ( e instanceof NoViableAltException ) {
NoViableAltException nvae = (NoViableAltException)e;
msg = " no viable alt; token="+e.token+
" (decision="+nvae.decisionNumber+
" state "+nvae.stateNumber+")"+
" decision=<<"+nvae.grammarDecisionDescription+">>";
}
else if( e instanceof FailedPredicateException ) {
FailedPredicateException fpe = (FailedPredicateException)e;
msg = "failed predicate; token="+fpe.token+
" (rule="+fpe.ruleName+" predicate="+fpe.predicateText+")";
}
else {
msg = super.getErrorMessage(e, tokenNames);
}
return stack+" "+msg;
}
public String getTokenErrorDisplay(Token t) {
return t.toString();
}