docs: improve documentation of rust API

crates/feco3/src/cover.rs

@@ -7,9 +7,11 @@ use crate::record::Record;
 use crate::schemas::{LineParser, LiteralLineParser};
 use crate::Error;
 
-/// Summary information about the filing.
+/// The cover line in an FecFile.
 ///
-/// See https://github.com/NickCrews/feco3/wiki for more info.
+/// See
+/// [https://github.com/NickCrews/feco3/wiki](https://github.com/NickCrews/feco3/wiki)
+/// for more info.
 #[derive(Debug, Clone, Default)]
 pub struct Cover {
  /// What form is this .fec file, eg "F3X"

crates/feco3/src/header.rs

@@ -18,9 +18,11 @@ use std::result::Result;
 
 use crate::schemas::LiteralLineParser;
 
-/// The header of a FEC file.
+/// The header of a FecFile.
 ///
-/// See https://github.com/NickCrews/feco3/wiki for more info.
+/// See
+/// [https://github.com/NickCrews/feco3/wiki](https://github.com/NickCrews/feco3/wiki)
+/// for more info.
 ///
 /// There might be other bits of information available,
 /// but currently we only parse this subset.

crates/feco3/src/lib.rs

@@ -9,8 +9,8 @@
 //! streams, or a custom source.
 //!
 //! FECo3 includes a framework for writing the parsed data. Currently,
-//! the only supported output format is CSV, but the framework is designed
-//! to be extensible to other formats.
+//! writing to a directory of .csvs or .parquet files are built in,
+//! but the framework is designed to be extensible to other formats.
 //!
 //! There are bindings for python available
 //! [on the repo](https://github.com/NickCrews/feco3).
@@ -31,6 +31,7 @@ pub use crate::fec::FecFile;
 pub use crate::fec::LineIter;
 pub use crate::header::Header;
 
+/// The error type for this crate.
 #[derive(thiserror::Error, Debug)]
 pub enum Error {
  #[allow(missing_docs)]

crates/feco3/src/record.rs

@@ -1,6 +1,8 @@
 //! Single itemization records from an .fec file.
 //!
-//! See https://github.com/NickCrews/feco3/wiki for more
+//! See
+//! [https://github.com/NickCrews/feco3/wiki](https://github.com/NickCrews/feco3/wiki)
+//! for more info
 
 use std::fmt;
 use std::hash::Hash;
@@ -100,7 +102,9 @@ pub struct FieldSchema {
 
 /// A parsed line of a .FEC file.
 ///
-/// See https://github.com/NickCrews/feco3/wiki/.fec-File-Format for more.
+/// See
+/// [https://github.com/NickCrews/feco3/wiki](https://github.com/NickCrews/feco3/wiki)
+/// for more info
 #[derive(Debug, Clone)]
 pub struct Record {
  /// The record type code that begins the line in the .fec file, eg "SA11"

crates/feco3/src/writers/arrow.rs

@@ -1,4 +1,4 @@
-//! Helpers for converting [Record]s into arrow [RecordBatch]es.
+//! Convert [Record]s into arrow [RecordBatch]es.
 use arrow::array::{
  ArrayBuilder, BooleanBuilder, Date32Builder, Float64Builder, Int64Builder, StringBuilder,
 };

crates/feco3/src/writers/base.rs

@@ -21,7 +21,7 @@ pub trait RecordWriterFactory: Send {
  fn make_writer(&mut self, schema: &RecordSchema) -> std::io::Result<Self::Writer>;
 }
 
-/// Creates [RecordWriter]s that write to a filea.
+/// Creates [RecordWriter]s that write to a file.
 pub trait FileRecordWriterFactory: Send {
  type Writer: RecordWriter;
  fn file_name(&self, form_name: String) -> String;

crates/feco3/src/writers/csv.rs

@@ -66,11 +66,17 @@ impl FileRecordWriterFactory for CSVFileWriterFactory {
  }
 }
 
+/// Writes forms to a directory of CSV files.
+///
+/// Each form type gets its own file. If the form type contains a "/"
+/// (which would result in a subdirectory), it is replaced with a "-".
+/// For example, "SC/10" would be written to "SC-10.csv".
 pub struct CSVProcessor {
  multi_writer: MultiRecordWriter<MultiFileRecordWriterFactory<CSVFileWriterFactory>>,
 }
 
 impl CSVProcessor {
+ /// Create a new CSVProcessor that writes to the given directory.
  pub fn new(out_dir: PathBuf) -> Self {
  let factory = CSVFileWriterFactory;
  let f2 = MultiFileRecordWriterFactory::new(out_dir, factory);
@@ -79,6 +85,7 @@ impl CSVProcessor {
  }
 
  // TODO: factor this out with ParquetProcessor.process()
+ /// Process the given FEC file, writing the results to the output directory.
  pub fn process(&mut self, fec: &mut FecFile) -> Result<(), Error> {
  let fec_version = fec.get_header()?.fec_version.clone();
  let mut parser = CoercingLineParser;

crates/feco3/src/writers/mod.rs

@@ -1,4 +1,4 @@
-//! Writers for the parsed data.
+//! Writers for individual [crate::record::Record]s
 
 pub mod arrow;
 pub mod base;

crates/feco3/src/writers/parquet.rs

@@ -77,12 +77,20 @@ impl FileRecordWriterFactory for ParquetWriterFactory {
  }
 }
 
-/// Processes an entire FEC file, writing each form to a separate file.
+/// Writes forms to a directory of CSV files.
+///
+/// Each form type gets its own file. If the form type contains a "/"
+/// (which would result in a subdirectory), it is replaced with a "-".
+/// For example, "SC/10" would be written to "SC-10.csv".
 pub struct ParquetProcessor {
  writer: MultiRecordWriter<MultiFileRecordWriterFactory<ParquetWriterFactory>>,
 }
 
 impl ParquetProcessor {
+ /// Create a new CSVProcessor that writes to the given directory.
+ ///
+ /// `writer_props` can be used to configure the parquet writer used for
+ /// each file. If None, the default writer properties are used.
  pub fn new(out_dir: PathBuf, writer_props: Option<WriterProperties>) -> Self {
  let factory = ParquetWriterFactory {
  props: writer_props,