Crate nexcore_dataframe 

nexcore-dataframe

Sovereign columnar DataFrame engine for NexCore.

Zero unsafe code, zero external DataFrame dependency. Replaces polars across the workspace, eliminating CRITICAL (fast-float segfault) and HIGH (pyo3 buffer overflow) transitive vulnerabilities.

Core types

• DataFrame — columnar table with named, typed columns
• Column — named array of homogeneous nullable values
• Scalar — single typed value for comparisons and aggregation results
• Counter — optimized hash-based group-count (replaces polars group_by+count)
• Schema — column name → type mapping

Operations

• Filter: df.filter(&mask), df.filter_by("col", |v| pred)
• Sort: df.sort("col", descending), df.head(n), df.tail(n)
• Select: df.select(&["col1", "col2"]), df.drop_columns(&["col"])
• Aggregate: col.sum(), col.mean(), col.min(), col.max(), col.median()
• GroupBy: df.group_by(&["col"])?.agg(&[Agg::Sum("val".into())])
• Join: df.join(&other, &["key"], JoinType::Inner) (inner/left/right/outer/semi/anti)
• I/O: DataFrame::from_json(s), df.to_json(), df.to_json_file(path)

Re-exports

pub use column::Column;

pub use column::ColumnData;

pub use column::DataType;

pub use counter::Counter;

pub use dataframe::DataFrame;

pub use error::DataFrameError;

pub use group::Agg;

pub use join::JoinType;

pub use scalar::Scalar;

pub use schema::Schema;

Modules

agg

Scalar aggregation functions on columns.

column

Column: a named, typed array — the fundamental storage unit.

counter

Counter: optimized hash-based group-count for the FAERS pipeline.

dataframe

DataFrame: the core columnar data structure.

error

DataFrame error types.

filter

Filtering operations on DataFrames.

group

GroupBy: hash-based grouping with aggregation.

io

I/O operations for DataFrames.

join

Join: hash-based join operations on DataFrames.

prelude

Prelude: import everything needed for typical DataFrame usage.

scalar

Scalar: a single typed value for heterogeneous operations.

schema

Schema: column name → DataType mapping.

select

Column selection operations on DataFrames.

sort

Sorting operations on DataFrames.