package nebula.simpletemplate;
import org.antlr.runtime.Token;
/**
* Represents the name of a formal argument defined in a template:
* <pre>
* test(a,b,x=defaultvalue) ::= "<a> <n> <x>"
* </pre> Each template has a set of these formal arguments or sets
* {@link CompiledST#hasFormalArgs} to {@code false} (indicating that no
* arguments were specified such as when we create a template with
* {@code new ST(...)}).
* <p/>
* Note: originally, I tracked cardinality as well as the name of an attribute.
* I'm leaving the code here as I suspect something may come of it later.
* Currently, though, cardinality is not used.
*/
public class FormalArgument {
/*
// the following represent bit positions emulating a cardinality bitset.
public static final int OPTIONAL = 1; // a?
public static final int REQUIRED = 2; // a
public static final int ZERO_OR_MORE = 4; // a*
public static final int ONE_OR_MORE = 8; // a+
public static final String[] suffixes = {
null,
"?",
"",
null,
"*",
null,
null,
null,
"+"
};
protected int cardinality = REQUIRED;
*/
public String name;
public int index; // which argument is it? from 0..n-1
/** If they specified default value {@code x=y}, store the token here */
public Token defaultValueToken;
public Object defaultValue; // x="str", x=true, x=false
public CompiledST compiledDefaultValue; // x={...}
public FormalArgument(String name) { this.name = name; }
public FormalArgument(String name, Token defaultValueToken) {
this.name = name;
this.defaultValueToken = defaultValueToken;
}
/*
public static String getCardinalityName(int cardinality) {
switch (cardinality) {
case OPTIONAL : return "optional";
case REQUIRED : return "exactly one";
case ZERO_OR_MORE : return "zero-or-more";
case ONE_OR_MORE : return "one-or-more";
default : return "unknown";
}
}
*/
@Override
public int hashCode() {
return name.hashCode() + defaultValueToken.hashCode();
}
@Override
public boolean equals(Object o) {
if ( o==null || !(o instanceof FormalArgument) ) {
return false;
}
FormalArgument other = (FormalArgument)o;
if ( !this.name.equals(other.name) ) {
return false;
}
// only check if there is a default value; that's all
return !((this.defaultValueToken != null && other.defaultValueToken == null) ||
(this.defaultValueToken == null && other.defaultValueToken != null));
}
@Override
public String toString() {
if ( defaultValueToken!=null ) return name+"="+defaultValueToken.getText();
return name;
}
}