Expr.resolve

ExprInfo resolve(DataFrame df) @safe

Resolves the expression against a frame's schema (column names and dtypes only; no data is touched).

Parameters

dfthe frame whose schema resolves the columns

Returns

the resolved metadata.
ExprInfo resolve(scope ColumnSchema[] schema) @safe

Resolves the expression against an explicit input schema: the output dtype, conservative nullability, row cardinality and column dependencies. This is the inspection entry the plan layer and the optimizer use at collection time.

Parameters

schemathe input columns

Returns

the resolved metadata.

Throws

DataFrameException for unknown columns, non-BOOLEAN

when masks or operand pairs with no common dtype.