Package gavo :: Package adql :: Module nodes

Module nodes

Node classes and factories used in ADQL tree processing.

Classes
	ReplaceNode can be raised by code in the constructor of and ADQLNode to replace itself.
	BOMB_OUT
	ADQLNode A node within an ADQL parse tree.
	TransparentMixin a mixin just pulling through the children and serializing them.
	FieldInfoedNode An ADQL node that carries a FieldInfo.
	FunctionNode An ADQLNodes having a function name and arguments.
	ColumnBearingNode A Node types defining selectable columns.
	TableName
	PlainTableRef A reference to a simple table.
	DerivedTable
	JoinSpecification A join specification ("ON" or "USING").
	JoinOperator the complete join operator (including all LEFT, RIGHT, ",", and whatever).
	JoinedTable A joined table.
	SubJoin A sub join (JoinedTable surrounded by parens).
	TransparentNode An abstract base for Nodes that don't parse out anything.
	WhereClause
	Grouping
	Having
	OrderBy
	OffsetSpec
	SelectNoParens
	SetOperationNode A node containing a set expression.
	SetTerm
	WithQuery A query from a with clause.
	SelectQuery A complete query excluding CTEs.
	QuerySpecification The toplevel query objects including CTEs.
	ColumnReference
	ColumnReferenceByUCD
	FromClause
	DerivedColumn A column within a select list.
	QualifiedStar
	SelectList
	Comparison is required when we want to morph the braindead contains(...)=1 into a true boolean function call.
	Factor is a factor within an SQL expression.
	ArrayReference
	CombiningFINode
	Term
	NumericValueExpression
	StringValueExpression
	GenericValueExpression A container for value expressions that we don't want to look at closer.
	SetFunction An aggregate function.
	NumericValueFunction A numeric function.
	StringValueFunction
	TimestampFunction
	InUnitFunction
	CharacterStringLiteral according to the current grammar, these are always sequences of quoted strings.
	CastSpecification
	CoosysMixin is a mixin that works cooSys into FieldInfos for ADQL geometries.
	GeometryNode Nodes for geometry constructors.
	Point
	Circle A circle parsed from ADQL.
	Box
	PolygonCoos a base class for the various argument forms of polygons.
	PolygonSplitCooArgs
	PolygonPointCooArgs
	Polygon
	STCSRegion
	Centroid
	Distance
	PredicateGeometryFunction
	PointFunction
	Area

Functions

symbolAction(*symbols)
is a decorator to mark functions as being a parseAction for symbol.

source code

getType(arg)
returns the type of an ADQL node or the value of str if arg is a string.

source code

flatten(arg)
returns the SQL serialized representation of arg.

source code

autocollapse(nodeBuilder, children)
inhibts the construction via nodeBuilder if children consists of a single ADQLNode.

source code

collectUserData(infoChildren)

source code

flattenKWs(obj, *fmtTuples)
returns a string built from the obj according to format tuples.

source code

cleanNamespace(ns)
removes all names starting with an underscore from the dict ns.

source code

getChildrenOfType(nodeSeq, type)
returns a list of children of type typ in the sequence nodeSeq.

source code

getChildrenOfClass(nodeSeq, cls)

source code

getChildOfType(nodeSeq, type, default=<class 'gavo.adql.nodes.BOMB_OUT'>)
returns the unique node of type in nodeSeq.

source code

getChildOfClass(nodeSeq, cls, default=<class 'gavo.adql.nodes.BOMB_OUT'>)
returns the unique node of class in nodeSeq.

source code

parseArgs(parseResult)
returns a sequence of ADQL nodes suitable as function arguments from parseResult.

source code

makeBinaryJoinTree(children)
takes the parse result for a join and generates a binary tree of JoinedTable nodes from it.

source code

dispatchColumnReference(parseResult)

source code

makeValueExpression(children)

source code

registerRegionMaker(fun)
adds a region maker to the region resolution chain.

source code

makeRegion(children)

source code

makeSTCSRegion(spec)

source code

Variables
	__package__ = `'gavo.adql'`

Function Details

symbolAction(*symbols)

source code

is a decorator to mark functions as being a parseAction for symbol.

This is evaluated by getADQLGrammar below. Be careful not to alter global state in such a handler.

autocollapse(nodeBuilder, children)

source code

inhibts the construction via nodeBuilder if children consists of a single ADQLNode.

This function will automatically be inserted into the the constructor chain if the node defines an attribute collapsible=True.

flattenKWs(obj, *fmtTuples)

source code

returns a string built from the obj according to format tuples.

A format tuple is consists of a literal string, and an attribute name. If the corresponding attribute is non-None, the plain string and the flattened attribute value are inserted into the result string, otherwise both are ignored.

Nonexisting attributes are taken to have None values.

To allow unconditional literals, the attribute name can be None. The corresponding literal is always inserted.

All contributions are separated by single blanks.

This is a helper method for flatten methods of parsed-out elements.

cleanNamespace(ns)

source code

removes all names starting with an underscore from the dict ns.

This is intended for _getInitKWs methods. ns is changed in place *and* returned for convenience

getChildOfType(nodeSeq, type, default=<class 'gavo.adql.nodes.BOMB_OUT'>)

source code

returns the unique node of type in nodeSeq.

If there is no such node in nodeSeq or more than one, a NoChild or MoreThanOneChild exception is raised, Instead of raising NoChild, default is returned if given.

getChildOfClass(nodeSeq, cls, default=<class 'gavo.adql.nodes.BOMB_OUT'>)

source code

returns the unique node of class in nodeSeq.

See getChildOfType.

parseArgs(parseResult)

source code

returns a sequence of ADQL nodes suitable as function arguments from parseResult.

This is for cleaning up _parseResults["args"], i.e. stuff from the Args symbol decorator in grammar.

makeBinaryJoinTree(children)

source code

takes the parse result for a join and generates a binary tree of JoinedTable nodes from it.

It's much easier to do this in a separate step than to force a non-left-recursive grammar to spit out the right parse tree in the first place.

Decorators:

@symbolAction("joinedTable")

dispatchColumnReference(parseResult)

source code

Decorators:

@symbolAction("columnReference")

makeValueExpression(children)

source code

Decorators:

@symbolAction("valueExpression")

registerRegionMaker(fun)

source code

adds a region maker to the region resolution chain.

region makers are functions taking the argument to REGION and trying to do something with it. They should return either some kind of FieldInfoedNode that will then replace the REGION or None, in which case the next function will be tried.

As a convention, region specifiers here should always start with an identifier (like simbad, siapBbox, etc, basically [A-Za-z]+). The rest is up to the region maker, but whitespace should separate this rest from the identifier.

The entire region functionality will probably disappear with TAP 1.1. Don't do anything with it any more. Use ufuncs instead.

makeRegion(children)

source code

Decorators:

@symbolAction("region")