如果您看到我以前的帖子，我仍在研究相同的基于 Haskell 的语法。大多数错误现在都消失了，但我还有另一个问题。
我的语法如下我知道这是一个非常大而且很乏味的东西，但是我的期末考试需要这个，所以我很抱歉，我很感激任何帮助：（很多逻辑都丢失了，但这些都是需要规则）
grammar T;
options {
language=Java;
backtrack=true;
}
tokens{
NUM = 'num';
LIST = 'list';
EVEN = 'even';
ODD = 'odd';
TWICE = 'twice';
HEAD = 'head';
TAIL = 'tail';
LENGTH = 'length';
MAX = 'max';
REV = 'reverse';
INC = 'incAll';
SORT = 'sort';
KEEP = 'keep';
DROP = 'drop';
POLY = 'poly';
}
@header {
import java.util.Hashtable;
import java.util.ArrayList;
}
@members
{
Hashtable <String, Integer> intMemory= new Hashtable<String, Integer>();
Hashtable <String, ArrayList> listMemory= new Hashtable <String, ArrayList>();
}
prog: stat+
;
stat: numDecl ';' //declares a variable containing an int
|listDecl ';' //declares a variable containing a list
|numAdd ';' //adds two integers directly or through getting from the int hashtable
|numEven ';' //determines whether or not int or id value is even
|numOdd ';' //determines whether or not int or id value is odd
|numTwice ';' {System.out.println($numTwice.value);} //double values and prints
|listHead ';' {System.out.println($listHead.value);} //returns list head
|listTail ';' //returns list tail
|listLength ';' //{System.out.println($listLength.value);} // returns list length
|listConc ';' //{System.out.println($listConc.value);} //concatenates 2 lists
|listMax ';' //{System.out.println($listMax.value);} //returns max of a list
|listReverse ';' //{System.out.println($listReverse.value);}//reverses a list
|listInc ';' //{System.out.println($listInc.value);} //increments each list value by 1
|listSort ';' //{System.out.println($listSort.value);}//sorts a list
|listConst ';' //{System.out.println($listConst.value);}//constructs a list from another one
|bothKeep ';' //{System.out.println($bothKeep.value);}// keeps a specified number of elements from a list
|bothDrop ';' //{System.out.println($bothDrop.value);}// drops a specified number of elements from the list
|bothPoly ';' //{System.out.println($bothPoly.value);}//evaluates a polynomial at a certain value
;
numDecl:
NUM ID '=' atom {intMemory.put($ID.text, new Integer($atom.value));}
;
listDecl
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
LIST ID '=' '[' a1=atom {list.add($a1.value);} (',' a2=atom {list.add($a2.value);} )* ']' {listMemory.put($ID.text, list);}
;
numAdd returns [int value]:
e=numMult {$value=$e.value;} ('+' e1=numMult {$value+=$e1.value;} | '-' e1=numMult {$value-=$e1.value;})* {System.out.println($numAdd.value);}
;
numMult returns [int value]:
e=atom {$value=$e.value;} ('*' e1=atom {$value*=$e1.value;} | '/' e1=atom {if($e1.value !=0) $value/=$e1.value;
else System.out.println ("Division by 0 is impossible");})*
;
numEven:
EVEN (WS)+ atom {if ($atom.value\%2==0) System.out.println("Is Even.");}
;
numOdd:
ODD (WS)+ atom {if ($atom.value\%2==1) System.out.println("Is Odd.");}
;
numTwice returns [int value]:
TWICE (WS)+ atom {$value= 2*($atom.value); System.out.println($value);}
;
listHead returns [int value]:
HEAD headTail
;
headTail returns [int value]:
ID {$value= (Integer) listMemory.get($ID.text).get(0);}
|'[' x=atom (',' atom )*']' {$value=$x.value;}
;
listTail:
TAIL tailTail
;
tailTail
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
ID {System.out.println("[ "); for (int i=1; i<listMemory.size();i++) System.out.println(listMemory.get($ID.text).get(i)+","); System.out.println(" ]");}
|'[' a1=atom {list.add($a1.value);} (',' a2=atom{list.add($a2.value);} )* ']' {System.out.println("[ "); for (int i=1; i<list.size();i++) System.out.println(list.get (i)+","); System.out.println(" ]");}
;
listLength:
LENGTH lengthTail
;
lengthTail returns [int value]
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
ID {$value=listMemory.get($ID.text).size();}
| '[' a1=atom {list.add($a1.value);} (',' a2=atom{list.add($a2.value);} )* ']' {$value=list.size();}
;
listConc:
ID '+' '+' concTail
|'[' atom(',' atom)*']' '+' '+' concTail
;
concTail returns [ArrayList list]:
ID {$list=listMemory.get($ID.text);}
| '[' atom(',' atom)*']'
;
listMax:
MAX maxTail
;
maxTail: ID
| '[' atom (',' atom )*']'
;
listReverse:
REV revTail
;
revTail:
ID
| '[' atom (',' atom )*']'
;
listInc:
INC incTail
;
incTail:
ID
| '[' atom (',' atom )*']'
;
listSort:
SORT sortTail
;
sortTail:
ID
|'[' atom (',' atom )*']'
;
listConst:
'[' atom constTail '|' ID '<-' ID ']'
;
constTail:
'+' atom
|'-' atom
|'*' atom
|'/' atom
;
bothKeep:
KEEP atom keepTail
;
keepTail
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
'[' a1=atom {list.add($a1.value);} (',' a2=atom{list.add($a2.value);} )* ']'
|ID
;
bothDrop:
DROP atom dropTail
;
dropTail returns [ArrayList value]
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
'[' a1=atom {list.add($a1.value);} (',' a2=atom{list.add($a2.value);} )* ']'
|ID
;
bothPoly:
POLY atom polyTail
;
polyTail returns [ArrayList value]
@init {
int count = 0;
ArrayList<Integer> list = new ArrayList<Integer>();
}:
'[' a1=atom {list.add($a1.value);} (',' a2=atom{list.add($a2.value);} )* ']' {$value=list;}
|ID
;
atom returns [int value]:
INT {$value = Integer.parseInt ($INT.text);}
| ID
{
Integer v= (Integer)intMemory.get($ID.text);
if (v!=null) {$value=v.intValue();}
else {
System.err.println("Undefined variable "+$ID.text);
}
}
| '(' numAdd ')' {$value=$numAdd.value;}
;
Letter: 'a'..'z';
Digit: '0'..'9';
ID : 'a'..'z'('0'..'9')*;
INT : '0'..'9'+ ;
WS : (' '|'\t'|'\n'|'\r')+ {skip();} ;
我在列表中没有给它以下输入，因为我还没有实现它们的方法：
num x=4;
num y=9;
x+2;
2+3;
2-3;
x-2;
2*3;
x*2;
2/4;
x/3;
x/0;
even x;
odd 5;
odd y;
twice x;
twice y;
twice 2;
当我通过命令提示符运行它时，我得到以下信息：
C:\Users\Kamal\Desktop\Antlr>java -cp .;antlr-3.2.jar org.antlr.Tool T.g
C:\Users\Kamal\Desktop\Antlr>javac -cp .;antlr-3.2.jar *.java
C:\Users\Kamal\Desktop\Antlr>java -cp .;antlr-3.2.jar TestT
line 1:4 mismatched input 'x' expecting ID
line 2:4 mismatched input 'y' expecting ID
我将不胜感激。即使没有人能真正回答。非常感谢！