@Predicate(
Signature = "str_len/2",
Template = {"+atom,?integer"},
Reference = "Get string length.")
@Determined
public static final boolean predicateSTRLEN(final Goal goal, final TermStruct predicate) {
final Term argLeft = Utils.getTermFromElement(predicate.getElement(0));
final Term argRight = Utils.getTermFromElement(predicate.getElement(1));
TermInteger result = new TermInteger(argLeft.getText().length());
return argRight.Equ(result);
}
@Predicate(
Signature = "str_trim/2",
Template = {"+atom,?atom"},
Reference = "Trim string.")
@Determined
public static final boolean predicateSTRTRIM(final Goal goal, final TermStruct predicate) {
final Term argLeft = Utils.getTermFromElement(predicate.getElement(0));
final Term argRight = Utils.getTermFromElement(predicate.getElement(1));
Term result = new Term(argLeft.getText().trim());
return argRight.Equ(result);
}
@Predicate(
Signature = "upper_lower/2",
Template = {"+atom,?atom", "?atom,+atom"},
Reference = "Allows to make upper or lower case text version of an atom.")
@Determined
public static final boolean predicateUPPERLOWER(final Goal goal, final TermStruct predicate) {
final Term argLeft = Utils.getTermFromElement(predicate.getElement(0));
final Term argRight = Utils.getTermFromElement(predicate.getElement(1));
if (argLeft.getTermType() == Term.TYPE_ATOM) {
// the first case
Term term = new Term(argLeft.getText().toLowerCase());
return argRight.Equ(term);
} else {
// the second case
Term term = new Term(argRight.getText().toUpperCase());
return argLeft.Equ(term);
}
}
@Predicate(
Signature = "concat/3",
Template = {"+atom,+atom,?atom", "+atom,?atom,+atom", "?atom,+atom,+atom"},
Reference = "Concat two strings.")
@Determined
public static final boolean predicateCONCAT(final Goal goal, final TermStruct predicate) {
final Term argFIRST = Utils.getTermFromElement(predicate.getElement(0));
final Term argSECOND = Utils.getTermFromElement(predicate.getElement(1));
final Term argTHIRD = Utils.getTermFromElement(predicate.getElement(2));
if (argFIRST.getTermType() == Term.TYPE_ATOM) {
if (argSECOND.getTermType() == Term.TYPE_ATOM) {
// the first case
StringBuilder bldr = new StringBuilder(argFIRST.getText());
bldr.append(argSECOND.getText());
Term term = new Term(bldr.toString());
return argTHIRD.Equ(term);
} else {
// the second case
String startText = argFIRST.getText();
String fullText = argTHIRD.getText();
if (startText.length() > fullText.length()) return false;
String endText = fullText.substring(startText.length());
Term second = new Term(endText);
return argSECOND.Equ(second);
}
} else {
// the third case
String endText = argSECOND.getText();
String fullText = argTHIRD.getText();
if (endText.length() > fullText.length()) return false;
String startText = fullText.substring(0, fullText.length() - endText.length());
Term first = new Term(startText);
return argFIRST.Equ(first);
}
}
@Predicate(
Signature = "str_real/2",
Template = {"+atom,?number", "?atom,+number"},
Reference = "Convert a text atom to a real numeric atom (or back).")
@Determined
public static final boolean predicateSTRREAL(final Goal goal, final TermStruct predicate) {
final Term argLeft = Utils.getTermFromElement(predicate.getElement(0));
final Term argRight = Utils.getTermFromElement(predicate.getElement(1));
if (argLeft.getTermType() == Term.TYPE_ATOM) {
// the first case
TermFloat result = null;
try {
result = new TermFloat(argLeft.getText().trim());
} catch (NumberFormatException ex) {
return false;
}
return argRight.Equ(result);
} else {
// the second case
Term result = new Term(argRight.getText());
return argLeft.Equ(result);
}
}