schrodinger.application.desmond.antlr3.treewizard module

@package antlr3.tree @brief ANTLR3 runtime package, treewizard module

A utility module to create ASTs at runtime. See <http://www.antlr.org/wiki/display/~admin/2007/07/02/Exploring+Concept+of+TreeWizard> for an overview. Note that the API of the Python implementation is slightly different.

schrodinger.application.desmond.antlr3.treewizard.computeTokenTypes(tokenNames)

Compute a dict that is an inverted index of tokenNames (which maps int token types to names).

class schrodinger.application.desmond.antlr3.treewizard.TreePatternLexer(pattern)

Bases: object

__init__(pattern)

nextToken()

consume()

class schrodinger.application.desmond.antlr3.treewizard.TreePatternParser(tokenizer, wizard, adaptor)

Bases: object

__init__(tokenizer, wizard, adaptor)

pattern()

parseTree()

parseNode()

class schrodinger.application.desmond.antlr3.treewizard.TreePattern(payload)

Bases: schrodinger.application.desmond.antlr3.tree.CommonTree

When using %label:TOKENNAME in a tree for parse(), we must track the label.

__init__(payload)

Create a new node from an existing node does nothing for BaseTree as there are no fields other than the children list, which cannot be copied as the children are not considered part of this node.

toString()

Override to say how a node (not a tree) should look as text

class schrodinger.application.desmond.antlr3.treewizard.WildcardTreePattern(payload)

Bases: schrodinger.application.desmond.antlr3.treewizard.TreePattern

class schrodinger.application.desmond.antlr3.treewizard.TreePatternTreeAdaptor

Bases: schrodinger.application.desmond.antlr3.tree.CommonTreeAdaptor

This adaptor creates TreePattern objects for use during scan()

createWithPayload(payload)

Create a tree node from Token object; for CommonTree type trees, then the token just becomes the payload. This is the most common create call.

Override if you want another kind of node to be built.

class schrodinger.application.desmond.antlr3.treewizard.TreeWizard(adaptor=None, tokenNames=None, typeMap=None)

Bases: object

Build and navigate trees with this object. Must know about the names of tokens so you have to pass in a map or array of token names (from which this class can build the map). I.e., Token DECL means nothing unless the class can translate it to a token type.

In order to create nodes and navigate, this class needs a TreeAdaptor.

This class can build a token type -> node index for repeated use or for iterating over the various nodes with a particular type.

This class works in conjunction with the TreeAdaptor rather than moving all this functionality into the adaptor. An adaptor helps build and navigate trees using methods. This class helps you do it with string patterns like “(A B C)”. You can create a tree from that pattern or match subtrees against it.

__init__(adaptor=None, tokenNames=None, typeMap=None)

getTokenType(tokenName)

Using the map of token names to token types, return the type.

create(pattern)

Create a tree or node from the indicated tree pattern that closely follows ANTLR tree grammar tree element syntax:

(root child1 … child2).

You can also just pass in a node: ID

Any node can have a text argument: ID[foo] (notice there are no quotes around foo–it’s clear it’s a string).

nil is a special name meaning “give me a nil node”. Useful for making lists: (nil A B C) is a list of A B C.

index(tree)

Walk the entire tree and make a node name to nodes mapping.

For now, use recursion but later nonrecursive version may be more efficient. Returns a dict int -> list where the list is of your AST node type. The int is the token type of the node.

find(tree, what)

Return a list of matching token.

what may either be an integer specifzing the token type to find or a string with a pattern that must be matched.

visit(tree, what, visitor)

Visit every node in tree matching what, invoking the visitor.

If what is a string, it is parsed as a pattern and only matching subtrees will be visited. The implementation uses the root node of the pattern in combination with visit(t, ttype, visitor) so nil-rooted patterns are not allowed. Patterns with wildcard roots are also not allowed.

If what is an integer, it is used as a token type and visit will match all nodes of that type (this is faster than the pattern match). The labels arg of the visitor action method is never set (it’s None) since using a token type rather than a pattern doesn’t let us set a label.

parse(t, pattern, labels=None)

Given a pattern like (ASSIGN %lhs:ID %rhs:.) with optional labels on the various nodes and ‘.’ (dot) as the node/subtree wildcard, return true if the pattern matches and fill the labels Map with the labels pointing at the appropriate nodes. Return false if the pattern is malformed or the tree does not match.

If a node specifies a text arg in pattern, then that must match for that node in t.

equals(t1, t2, adaptor=None)

Compare t1 and t2; return true if token types/text, structure match exactly. The trees are examined in their entirety so that (A B) does not match (A B C) nor (A (B C)).