/**
* Copyright 2009, Google Inc. All rights reserved.
* Licensed to PSF under a Contributor Agreement.
*/
package org.python.indexer.ast;
import org.python.indexer.Indexer;
import org.python.indexer.NBinding;
import org.python.indexer.Scope;
import org.python.indexer.Util;
import org.python.indexer.types.NType;
import org.python.indexer.types.NModuleType;
import org.python.indexer.types.NUnknownType;
import java.io.File;
/**
* Recursive doubly-linked list representation of a qualified module name,
* either absolute or relative. Similar to {@link NAttribute}, but handles
* leading dots and other import-specific special cases.<p>
*
* Qualified names with leading dots are given {@code NQname} elements for each
* leading dot. Dots separating simple names are not given {@code NQname}
* elements. <p>
*/
public class NQname extends NNode {
static final long serialVersionUID = -5892553606852895686L;
private NQname next;
private NName name;
public NQname(NQname next, NName name) {
this(next, name, 0, 1);
}
public NQname(NQname next, NName name, int start, int end) {
super(start, end);
if (name == null)
throw new IllegalArgumentException("null name");
this.name = name;
this.next = next;
addChildren(name, next);
}
/**
* Returns this component of the qname chain.
*/
public NName getName() {
return name;
}
/**
* Returns the previous component of this qname chain, or {@code null} if
* this is the first component.
*/
public NQname getPrevious() {
NNode parent = getParent();
if (parent instanceof NQname) {
return (NQname)parent;
}
return null;
}
/**
* Returns the next component of the chain, or {@code null} if this is
* the last component.
*/
public NQname getNext() {
return next;
}
/**
* Returns the last/bottom component of the chain.
*/
public NQname getBottom() {
return next == null ? this : next.getBottom();
}
/**
* Returns {@code true} if this is the first/top component of the chain,
* or if the name is unqualified (i.e. has only one component, no dots).
*/
public boolean isTop() {
return getPrevious() == null;
}
/**
* Returns {@code true} if this is the last/bottom component of the chain,
* or if the name is unqualified (i.e. has only one component, no dots).
*/
public boolean isBottom() {
return next == null;
}
/**
* Returns {@code true} if this qname represents a simple, non-dotted module
* name such as "os", "random" or "foo".
*/
public boolean isUnqualified() {
return isTop() && isBottom();
}
/**
* Joins all components in this qname chain, beginning with the
* current component.
*/
public String toQname() {
return isBottom() ? name.id : name.id + "." + next.toQname();
}
/**
* Returns the qname down to (and including) this component, ending
* with this component's name. For instance, if this {@code NQname}
* instance represents the {@code foo} in {@code org.foo.bar}, this
* method will return {@code org.foo}.
*/
public String thisQname() {
NQname n = getTop();
StringBuilder sb = new StringBuilder();
sb.append(n.name.id);
while (n != this) {
sb.append(".");
n = n.next;
sb.append(n.name.id);
}
return sb.toString();
}
/**
* Returns the top (first) component in the chain.
*/
public NQname getTop() {
return isTop() ? this : getPrevious().getTop();
}
/**
* Returns {@code true} if this qname component is a leading dot.
*/
public boolean isDot() {
return ".".equals(name.id);
}
/**
* Resolves and loads the module named by this qname.
* @return the module represented by the qname up to this point.
*/
@Override
public NType resolve(Scope s) throws Exception {
setType(name.setType(new NUnknownType()));
// Check for top-level native or standard module.
if (isUnqualified()) {
NModuleType mt = Indexer.idx.loadModule(name.id);
if (mt != null) {
return setType(name.setType(mt));
}
} else {
// Check for second-level builtin such as "os.path".
NModuleType mt = Indexer.idx.getBuiltinModule(thisQname());
if (mt != null) {
setType(name.setType(mt));
resolveExpr(next, s);
return mt;
}
}
return resolveInFilesystem(s);
}
private NType resolveInFilesystem(Scope s) throws Exception {
NModuleType start = getStartModule(s);
if (start == null) {
reportUnresolvedModule();
return getType();
}
String qname = start.getTable().getPath();
String relQname;
if (isDot()) {
relQname = Util.getQnameParent(qname);
} else if (!isTop()) {
relQname = qname + "." + name.id;
} else {
// top name: first look in current dir, then sys.path
String dirQname = isInitPy() ? qname : Util.getQnameParent(qname);
relQname = dirQname + "." + name.id;
if (Indexer.idx.loadModule(relQname) == null) {
relQname = name.id;
}
}
NModuleType mod = Indexer.idx.loadModule(relQname);
if (mod == null) {
reportUnresolvedModule();
return getType();
}
setType(name.setType(mod));
if (!isTop() && mod.getFile() != null) {
Scope parentPkg = getPrevious().getTable();
NBinding mb = Indexer.idx.moduleTable.lookup(mod.getFile());
parentPkg.put(name.id, mb);
}
resolveExpr(next, s);
return getType();
}
private boolean isInitPy() {
String path = getFile();
if (path == null) {
return false;
}
return new File(path).getName().equals("__init__.py");
}
private NModuleType getStartModule(Scope s) throws Exception {
if (!isTop()) {
return getPrevious().getType().asModuleType();
}
// Start with module for current file (i.e. containing directory).
NModuleType start = null;
Scope mtable = s.getSymtabOfType(Scope.Type.MODULE);
if (mtable != null) {
start = Indexer.idx.loadModule(mtable.getPath());
if (start != null) {
return start;
}
}
String dir = new File(getFile()).getParent();
if (dir == null) {
Indexer.idx.warn("Unable to find parent dir for " + getFile());
return null;
}
return Indexer.idx.loadModule(dir);
}
private void reportUnresolvedModule() {
addError("module not found: " + name.id);
Indexer.idx.recordUnresolvedModule(thisQname(), getFile());
}
@Override
public String toString() {
return "<QName:" + name + ":" + next + ">";
}
@Override
public void visit(NNodeVisitor v) {
if (v.visit(this)) {
visitNode(next, v);
visitNode(name, v);
}
}
}