diff --git a/src/commands/_sample/spl.rs b/src/commands/_sample/spl.rs
index b695ab6..6471ea7 100644
--- a/src/commands/_sample/spl.rs
+++ b/src/commands/_sample/spl.rs
@@ -4,7 +4,7 @@ use crate::commands::ConvertCommandRoot;
 use crate::spl::ast;
 use crate::spl::ast::ParsedCommandOptions;
 use crate::spl::parser::{field, token, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
 use nom::multi::many0;
diff --git a/src/commands/cmd_add_totals/spl.rs b/src/commands/cmd_add_totals/spl.rs
index 243db56..27919be 100644
--- a/src/commands/cmd_add_totals/spl.rs
+++ b/src/commands/cmd_add_totals/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::multi::many0;
 use nom::sequence::pair;
diff --git a/src/commands/cmd_bin/spl.rs b/src/commands/cmd_bin/spl.rs
index 0de8c21..28ee06f 100644
--- a/src/commands/cmd_bin/spl.rs
+++ b/src/commands/cmd_bin/spl.rs
@@ -1,8 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
-use crate::spl::ast;
-use crate::spl::ast::{FieldOrAlias, ParsedCommandOptions, TimeSpan};
+use crate::spl::ast::*;
 use crate::spl::parser::{aliased_field, field};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::combinator::{into, map};
 use nom::sequence::pair;
@@ -59,12 +58,8 @@ impl TryFrom<ParsedCommandOptions> for BinCommandOptions {
 
     fn try_from(value: ParsedCommandOptions) -> Result<Self, Self::Error> {
         Ok(Self {
-            span: value.get_span_option("span")?.map(|span| match span {
-                ast::SplSpan::TimeSpan(s) => s,
-            }),
-            min_span: value.get_span_option("minspan")?.map(|span| match span {
-                ast::SplSpan::TimeSpan(s) => s,
-            }),
+            span: value.get_span_option("span")?,
+            min_span: value.get_span_option("minspan")?,
             bins: value.get_int_option("bins")?,
             start: value.get_int_option("start")?,
             end: value.get_int_option("end")?,
@@ -122,12 +117,12 @@ mod tests {
             Ok((
                 "",
                 BinCommand {
-                    field: _alias("bar", ast::Field::from("foo")).into(),
-                    span: Some(ast::TimeSpan {
+                    field: _alias("bar", Field::from("foo")).into(),
+                    span: Some(TimeSpan {
                         value: 30,
                         scale: "minutes".into()
                     }),
-                    min_span: Some(ast::TimeSpan {
+                    min_span: Some(TimeSpan {
                         value: 5,
                         scale: "minutes".into()
                     }),
diff --git a/src/commands/cmd_collect/spl.rs b/src/commands/cmd_collect/spl.rs
index a5e9ade..f91bf1a 100644
--- a/src/commands/cmd_collect/spl.rs
+++ b/src/commands/cmd_collect/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::field_list0;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use anyhow::anyhow;
 use nom::combinator::map;
 use nom::sequence::pair;
diff --git a/src/commands/cmd_convert/spl.rs b/src/commands/cmd_convert/spl.rs
index 4f3e3fc..ececc06 100644
--- a/src/commands/cmd_convert/spl.rs
+++ b/src/commands/cmd_convert/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field, token, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
 use nom::multi::many0;
diff --git a/src/commands/cmd_dedup/spl.rs b/src/commands/cmd_dedup/spl.rs
index f700fb9..dce555b 100644
--- a/src/commands/cmd_dedup/spl.rs
+++ b/src/commands/cmd_dedup/spl.rs
@@ -3,7 +3,7 @@ use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast;
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt, verify};
diff --git a/src/commands/cmd_eval/spl.rs b/src/commands/cmd_eval/spl.rs
index ba9bdcf..3f79cc9 100644
--- a/src/commands/cmd_eval/spl.rs
+++ b/src/commands/cmd_eval/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, Field, ParsedCommandOptions};
 use crate::spl::parser::{comma_separated_list0, expr, field, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag;
 use nom::combinator::map;
 use nom::sequence::separated_pair;
diff --git a/src/commands/cmd_event_stats/spl.rs b/src/commands/cmd_event_stats/spl.rs
index c3d90b8..083fc37 100644
--- a/src/commands/cmd_event_stats/spl.rs
+++ b/src/commands/cmd_event_stats/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, Field, ParsedCommandOptions};
 use crate::spl::parser::{field_list0, stats_call, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_fields/spl.rs b/src/commands/cmd_fields/spl.rs
index 5581306..4415724 100644
--- a/src/commands/cmd_fields/spl.rs
+++ b/src/commands/cmd_fields/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field_list1, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag;
 use nom::combinator::{map, opt};
diff --git a/src/commands/cmd_fill_null/spl.rs b/src/commands/cmd_fill_null/spl.rs
index fb98125..36bb323 100644
--- a/src/commands/cmd_fill_null/spl.rs
+++ b/src/commands/cmd_fill_null/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{double_quoted, field, token, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag;
 use nom::combinator::{into, map, opt};
diff --git a/src/commands/cmd_format/spl.rs b/src/commands/cmd_format/spl.rs
index 32b2f17..62f7924 100644
--- a/src/commands/cmd_format/spl.rs
+++ b/src/commands/cmd_format/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::ParsedCommandOptions;
 use crate::spl::parser::{double_quoted, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::{map, opt};
 use nom::sequence::{pair, tuple};
 use nom::IResult;
diff --git a/src/commands/cmd_head/spl.rs b/src/commands/cmd_head/spl.rs
index 22331c3..eee436d 100644
--- a/src/commands/cmd_head/spl.rs
+++ b/src/commands/cmd_head/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{BoolValue, Expr, ParsedCommandOptions};
 use crate::spl::parser::{bool_, expr, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
diff --git a/src/commands/cmd_input_lookup/spl.rs b/src/commands/cmd_input_lookup/spl.rs
index 75ef441..4f73643 100644
--- a/src/commands/cmd_input_lookup/spl.rs
+++ b/src/commands/cmd_input_lookup/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, ParsedCommandOptions};
 use crate::spl::parser::{expr, token, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_join/spl.rs b/src/commands/cmd_join/spl.rs
index f68e3d9..d4536d7 100644
--- a/src/commands/cmd_join/spl.rs
+++ b/src/commands/cmd_join/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions, Pipeline};
 use crate::spl::parser::{field_list1, sub_search};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::sequence::tuple;
 use nom::IResult;
diff --git a/src/commands/cmd_lookup/spl.rs b/src/commands/cmd_lookup/spl.rs
index 16a9fa1..88575d9 100644
--- a/src/commands/cmd_lookup/spl.rs
+++ b/src/commands/cmd_lookup/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{FieldLike, ParsedCommandOptions};
 use crate::spl::parser::{aliased_field, comma_or_space_separated_list1, field, token, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag_no_case;
 use nom::character::complete::multispace1;
diff --git a/src/commands/cmd_make_results/spl.rs b/src/commands/cmd_make_results/spl.rs
index cb74dbf..b9d42de 100644
--- a/src/commands/cmd_make_results/spl.rs
+++ b/src/commands/cmd_make_results/spl.rs
@@ -1,6 +1,6 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::ParsedCommandOptions;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::IResult;
 use pyo3::prelude::*;
diff --git a/src/commands/cmd_map/spl.rs b/src/commands/cmd_map/spl.rs
index 2849984..cb3569a 100644
--- a/src/commands/cmd_map/spl.rs
+++ b/src/commands/cmd_map/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{ParsedCommandOptions, Pipeline};
 use crate::spl::parser::quoted_search;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::sequence::pair;
 use nom::IResult;
diff --git a/src/commands/cmd_multi_search/spl.rs b/src/commands/cmd_multi_search/spl.rs
index 9ed3763..69428f3 100644
--- a/src/commands/cmd_multi_search/spl.rs
+++ b/src/commands/cmd_multi_search/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{ParsedCommandOptions, Pipeline};
 use crate::spl::parser::{sub_search, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::multi::many_m_n;
 use nom::IResult;
diff --git a/src/commands/cmd_mv_combine/spl.rs b/src/commands/cmd_mv_combine/spl.rs
index c9966bb..ff6bd68 100644
--- a/src/commands/cmd_mv_combine/spl.rs
+++ b/src/commands/cmd_mv_combine/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{double_quoted, field, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
 use nom::sequence::{pair, preceded};
diff --git a/src/commands/cmd_mv_expand/spl.rs b/src/commands/cmd_mv_expand/spl.rs
index fd8e4d5..943e123 100644
--- a/src/commands/cmd_mv_expand/spl.rs
+++ b/src/commands/cmd_mv_expand/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
 use nom::sequence::{pair, preceded};
diff --git a/src/commands/cmd_rare/spl.rs b/src/commands/cmd_rare/spl.rs
index ba8208a..f6441b6 100644
--- a/src/commands/cmd_rare/spl.rs
+++ b/src/commands/cmd_rare/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field_list0, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_regex/spl.rs b/src/commands/cmd_regex/spl.rs
index aef174b..845232f 100644
--- a/src/commands/cmd_regex/spl.rs
+++ b/src/commands/cmd_regex/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{double_quoted, field, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag;
 use nom::combinator::{map, opt};
diff --git a/src/commands/cmd_rename/spl.rs b/src/commands/cmd_rename/spl.rs
index 62861cd..cc691c6 100644
--- a/src/commands/cmd_rename/spl.rs
+++ b/src/commands/cmd_rename/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Alias, ParsedCommandOptions};
 use crate::spl::parser::{aliased_field, comma_separated_list1};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::IResult;
 use pyo3::prelude::*;
diff --git a/src/commands/cmd_return/spl.rs b/src/commands/cmd_return/spl.rs
index 5fd4b12..cf85f8a 100644
--- a/src/commands/cmd_return/spl.rs
+++ b/src/commands/cmd_return/spl.rs
@@ -2,7 +2,7 @@ use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast;
 use crate::spl::ast::{FieldOrAlias, IntValue, ParsedCommandOptions};
 use crate::spl::parser::{field, field_and_value, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag;
 use nom::combinator::{map, opt};
diff --git a/src/commands/cmd_rex/spl.rs b/src/commands/cmd_rex/spl.rs
index bcfe5b0..5798754 100644
--- a/src/commands/cmd_rex/spl.rs
+++ b/src/commands/cmd_rex/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::ParsedCommandOptions;
 use crate::spl::parser::double_quoted;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use anyhow::ensure;
 use nom::combinator::map;
 use nom::sequence::pair;
diff --git a/src/commands/cmd_s_path/spl.rs b/src/commands/cmd_s_path/spl.rs
index 5c8aed0..3e78c0d 100644
--- a/src/commands/cmd_s_path/spl.rs
+++ b/src/commands/cmd_s_path/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::ParsedCommandOptions;
 use crate::spl::parser::{field, string, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_search/spl.rs b/src/commands/cmd_search/spl.rs
index 5182f83..eb9cc46 100644
--- a/src/commands/cmd_search/spl.rs
+++ b/src/commands/cmd_search/spl.rs
@@ -3,7 +3,7 @@ use crate::spl::ast::{Expr, ParsedCommandOptions};
 use crate::spl::operators;
 use crate::spl::operators::OperatorSymbolTrait;
 use crate::spl::parser::{combine_all_expressions, comma_or_space_separated_list1, expr};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::tag_no_case;
 use nom::character::complete::{multispace0, multispace1};
diff --git a/src/commands/cmd_sort/spl.rs b/src/commands/cmd_sort/spl.rs
index b7a3b7d..9bf8d85 100644
--- a/src/commands/cmd_sort/spl.rs
+++ b/src/commands/cmd_sort/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, ParsedCommandOptions};
 use crate::spl::parser::{comma_separated_list1, expr, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
diff --git a/src/commands/cmd_stats/spl.rs b/src/commands/cmd_stats/spl.rs
index c0f0888..165fe3e 100644
--- a/src/commands/cmd_stats/spl.rs
+++ b/src/commands/cmd_stats/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, Field, ParsedCommandOptions};
 use crate::spl::parser::{bool_, field_list1, stats_call, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::combinator::{map, opt};
 use nom::sequence::{pair, preceded, tuple};
diff --git a/src/commands/cmd_stream_stats/spl.rs b/src/commands/cmd_stream_stats/spl.rs
index 24e2f29..44f0e82 100644
--- a/src/commands/cmd_stream_stats/spl.rs
+++ b/src/commands/cmd_stream_stats/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, Field, ParsedCommandOptions};
 use crate::spl::parser::{field_list0, stats_call, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_t_stats/spl.rs b/src/commands/cmd_t_stats/spl.rs
index c2edd74..dff9ff6 100644
--- a/src/commands/cmd_t_stats/spl.rs
+++ b/src/commands/cmd_t_stats/spl.rs
@@ -4,7 +4,7 @@ use crate::spl::parser::{
     comma_or_space_separated_list1, field, field_in, logical_expression, space_separated_list1,
     time_span, token, ws,
 };
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::branch::alt;
 use nom::bytes::complete::{tag, tag_no_case};
 use nom::character::complete::multispace1;
diff --git a/src/commands/cmd_table/spl.rs b/src/commands/cmd_table/spl.rs
index 06a10c1..020d9dc 100644
--- a/src/commands/cmd_table/spl.rs
+++ b/src/commands/cmd_table/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::field_list1;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::IResult;
 use pyo3::prelude::*;
diff --git a/src/commands/cmd_tail/spl.rs b/src/commands/cmd_tail/spl.rs
index d20f673..f0187e9 100644
--- a/src/commands/cmd_tail/spl.rs
+++ b/src/commands/cmd_tail/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::ParsedCommandOptions;
 use crate::spl::parser::int;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::IResult;
 use pyo3::prelude::*;
diff --git a/src/commands/cmd_top/spl.rs b/src/commands/cmd_top/spl.rs
index 74e11a2..61ae62b 100644
--- a/src/commands/cmd_top/spl.rs
+++ b/src/commands/cmd_top/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Field, ParsedCommandOptions};
 use crate::spl::parser::{field_list1, int, ws};
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::bytes::complete::tag_no_case;
 use nom::combinator::{map, opt};
 use nom::sequence::{preceded, tuple};
diff --git a/src/commands/cmd_where/spl.rs b/src/commands/cmd_where/spl.rs
index 31ed71b..ccf73dc 100644
--- a/src/commands/cmd_where/spl.rs
+++ b/src/commands/cmd_where/spl.rs
@@ -1,7 +1,7 @@
 use crate::commands::spl::{SplCommand, SplCommandOptions};
 use crate::spl::ast::{Expr, ParsedCommandOptions};
 use crate::spl::parser::logical_expression;
-use crate::spl::python::impl_pyclass;
+use crate::spl::python::*;
 use nom::combinator::map;
 use nom::IResult;
 use pyo3::prelude::*;
diff --git a/src/functions/mod.rs b/src/functions/mod.rs
index 5073748..9dd4e8a 100644
--- a/src/functions/mod.rs
+++ b/src/functions/mod.rs
@@ -52,7 +52,7 @@ impl TryFrom<ast::Expr> for String {
                 ast::Constant::SnapTime(_) => {
                     bail!("No default conversion from {:?} to String", const_)
                 }
-                ast::Constant::SplSpan(_) => {
+                ast::Constant::TimeSpan(_) => {
                     bail!("No default conversion from {:?} to String", const_)
                 }
                 ast::Constant::Field(ast::Field(val)) => Ok(val.clone()),
diff --git a/src/pyspark/transpiler/expr.rs b/src/pyspark/transpiler/expr.rs
index 005e34f..75bcdfc 100644
--- a/src/pyspark/transpiler/expr.rs
+++ b/src/pyspark/transpiler/expr.rs
@@ -154,9 +154,9 @@ impl TryFrom<ast::Expr> for Expr {
                             ast::Constant::SnapTime(ast::SnapTime { .. }) => {
                                 bail!("Unimplemented value in field-in rhs: {:?}", const_)
                             }
-                            ast::Constant::SplSpan(ast::SplSpan::TimeSpan(ast::TimeSpan {
-                                ..
-                            })) => bail!("Unimplemented value in field-in rhs: {:?}", const_),
+                            ast::Constant::TimeSpan(ast::TimeSpan { .. }) => {
+                                bail!("Unimplemented value in field-in rhs: {:?}", const_)
+                            }
                             ast::Constant::Field(ast::Field(val)) => {
                                 Ok(column_like!([c.clone()] == [Raw::from(val.clone())]))
                             }
diff --git a/src/spl/ast.rs b/src/spl/ast.rs
index 978d4ec..07953b1 100644
--- a/src/spl/ast.rs
+++ b/src/spl/ast.rs
@@ -195,7 +195,7 @@ case class Pipeline(commands: Seq[Command])
 use crate::commands::cmd_add_totals::spl::AddTotalsCommand;
 use crate::commands::cmd_bin::spl::BinCommand;
 use crate::commands::cmd_collect::spl::CollectCommand;
-use crate::commands::cmd_convert::spl::{ConvertCommand, FieldConversion};
+use crate::commands::cmd_convert::spl::ConvertCommand;
 use crate::commands::cmd_dedup::spl::DedupCommand;
 use crate::commands::cmd_eval::spl::EvalCommand;
 use crate::commands::cmd_event_stats::spl::EventStatsCommand;
@@ -243,45 +243,21 @@ pub struct NullValue();
 #[pyclass(frozen, eq, hash)]
 pub struct BoolValue(pub bool);
 
-impl<T: Into<bool>> From<T> for BoolValue {
-    fn from(value: T) -> Self {
-        BoolValue(value.into())
-    }
-}
-
 /// Syntax tree element representing an integer literal value.
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct IntValue(pub i64);
 
-impl<T: Into<i64>> From<T> for IntValue {
-    fn from(value: T) -> Self {
-        IntValue(value.into())
-    }
-}
-
 /// Syntax tree element representing a floating-point literal value.
 #[derive(Debug, PartialEq, Clone, FloatHash)]
 #[pyclass(frozen, eq, hash)]
 pub struct DoubleValue(pub f64);
 
-impl<T: Into<f64>> From<T> for DoubleValue {
-    fn from(value: T) -> Self {
-        DoubleValue(value.into())
-    }
-}
-
 /// Syntax tree element representing a string literal value.
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct StrValue(pub String);
 
-impl<T: ToString> From<T> for StrValue {
-    fn from(value: T) -> Self {
-        StrValue(value.to_string())
-    }
-}
-
 /// Syntax tree element representing a duration with a value and a scale.
 ///
 /// # Fields
@@ -312,42 +288,18 @@ pub struct SnapTime {
 #[pyclass(frozen, eq, hash)]
 pub struct Field(pub String);
 
-impl<S: ToString> From<S> for Field {
-    fn from(value: S) -> Field {
-        Field(value.to_string())
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct Wildcard(pub String);
 
-impl<S: ToString> From<S> for Wildcard {
-    fn from(value: S) -> Wildcard {
-        Wildcard(value.to_string())
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct Variable(pub String);
 
-impl<S: ToString> From<S> for Variable {
-    fn from(value: S) -> Variable {
-        Variable(value.to_string())
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct IPv4CIDR(pub String);
 
-impl<S: ToString> From<S> for IPv4CIDR {
-    fn from(value: S) -> IPv4CIDR {
-        IPv4CIDR(value.to_string())
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct FV {
@@ -464,9 +416,9 @@ impl ParsedCommandOptions {
             .map(|v| v.unwrap_or(default.to_string()))
     }
 
-    pub fn get_span_option(&self, key: &str) -> Result<Option<SplSpan>, anyhow::Error> {
+    pub fn get_span_option(&self, key: &str) -> Result<Option<TimeSpan>, anyhow::Error> {
         match self.inner.get(key) {
-            Some(Constant::SplSpan(span)) => Ok(Some(span.clone())),
+            Some(Constant::TimeSpan(span)) => Ok(Some(span.clone())),
             Some(_) => Err(anyhow!("not a span")),
             None => Ok(None),
         }
@@ -494,15 +446,6 @@ pub struct AliasedField {
     pub alias: String,
 }
 
-impl From<AliasedField> for Alias {
-    fn from(value: AliasedField) -> Self {
-        Alias {
-            expr: Box::new(value.field.into()),
-            name: value.alias,
-        }
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub struct Binary {
@@ -559,18 +502,19 @@ pub enum TimeModifier {
     Latest(SnapTime),
 }
 
-/// A pipeline is a chain of commands where data is passed and processed by each command in turn.
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
-pub struct Pipeline {
-    #[pyo3(get)]
-    pub commands: Vec<Command>,
+pub struct FormattedTimeModifier {
+    pub format: String,
+    pub time_modifier: TimeModifier,
 }
 
+/// A pipeline is a chain of commands where data is passed and processed by each command in turn.
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
-pub enum SplSpan {
-    TimeSpan(TimeSpan),
+pub struct Pipeline {
+    #[pyo3(get)]
+    pub commands: Vec<Command>,
 }
 
 #[derive(Debug, PartialEq, Clone, Hash)]
@@ -582,7 +526,7 @@ pub enum Constant {
     Double(DoubleValue),
     Str(StrValue),
     SnapTime(SnapTime),
-    SplSpan(SplSpan),
+    TimeSpan(TimeSpan),
     Field(Field),
     Wildcard(Wildcard),
     Variable(Variable),
@@ -621,174 +565,11 @@ pub enum Expr {
     Call(Call),
     FieldIn(FieldIn),
     Alias(Alias),
-    FieldConversion(FieldConversion),
-    TimeModifier(String, TimeModifier),
+    TimeModifier(FormattedTimeModifier),
     SearchModifier(SearchModifier),
     SubSearch(Pipeline),
 }
 
-impl From<TimeSpan> for Constant {
-    fn from(val: TimeSpan) -> Self {
-        Constant::SplSpan(SplSpan::TimeSpan(val))
-    }
-}
-impl From<BoolValue> for Constant {
-    fn from(val: BoolValue) -> Self {
-        Constant::Bool(val)
-    }
-}
-impl From<IntValue> for Constant {
-    fn from(val: IntValue) -> Self {
-        Constant::Int(val)
-    }
-}
-impl From<DoubleValue> for Constant {
-    fn from(val: DoubleValue) -> Self {
-        Constant::Double(val)
-    }
-}
-impl From<StrValue> for Constant {
-    fn from(val: StrValue) -> Self {
-        Constant::Str(val)
-    }
-}
-impl From<SnapTime> for Constant {
-    fn from(val: SnapTime) -> Self {
-        Constant::SnapTime(val)
-    }
-}
-impl From<Field> for Constant {
-    fn from(val: Field) -> Self {
-        Constant::Field(val)
-    }
-}
-impl From<Wildcard> for Constant {
-    fn from(val: Wildcard) -> Self {
-        Constant::Wildcard(val)
-    }
-}
-impl From<Variable> for Constant {
-    fn from(val: Variable) -> Self {
-        Constant::Variable(val)
-    }
-}
-impl From<IPv4CIDR> for Constant {
-    fn from(val: IPv4CIDR) -> Self {
-        Constant::IPv4CIDR(val)
-    }
-}
-
-impl From<Constant> for Expr {
-    fn from(val: Constant) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val))
-    }
-}
-impl From<TimeSpan> for Expr {
-    fn from(val: TimeSpan) -> Self {
-        <TimeSpan as Into<Constant>>::into(val).into()
-    }
-}
-impl From<BoolValue> for Expr {
-    fn from(val: BoolValue) -> Self {
-        <BoolValue as Into<Constant>>::into(val).into()
-    }
-}
-impl From<IntValue> for Expr {
-    fn from(val: IntValue) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<DoubleValue> for Expr {
-    fn from(val: DoubleValue) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<StrValue> for Expr {
-    fn from(val: StrValue) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<SnapTime> for Expr {
-    fn from(val: SnapTime) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<Field> for Expr {
-    fn from(val: Field) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<Wildcard> for Expr {
-    fn from(val: Wildcard) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<Variable> for Expr {
-    fn from(val: Variable) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<IPv4CIDR> for Expr {
-    fn from(val: IPv4CIDR) -> Self {
-        Expr::Leaf(LeafExpr::Constant(val.into()))
-    }
-}
-impl From<FV> for Expr {
-    fn from(val: FV) -> Self {
-        Expr::Leaf(LeafExpr::FV(val))
-    }
-}
-impl From<FB> for Expr {
-    fn from(val: FB) -> Self {
-        Expr::Leaf(LeafExpr::FB(val))
-    }
-}
-impl From<FC> for Expr {
-    fn from(val: FC) -> Self {
-        Expr::Leaf(LeafExpr::FC(val))
-    }
-}
-impl From<AliasedField> for Expr {
-    fn from(val: AliasedField) -> Self {
-        Expr::AliasedField(val)
-    }
-}
-impl From<Binary> for Expr {
-    fn from(val: Binary) -> Self {
-        Expr::Binary(val)
-    }
-}
-impl From<Unary> for Expr {
-    fn from(val: Unary) -> Self {
-        Expr::Unary(val)
-    }
-}
-impl From<Call> for Expr {
-    fn from(val: Call) -> Self {
-        Expr::Call(val)
-    }
-}
-impl From<FieldIn> for Expr {
-    fn from(val: FieldIn) -> Self {
-        Expr::FieldIn(val)
-    }
-}
-impl From<Alias> for Expr {
-    fn from(val: Alias) -> Self {
-        Expr::Alias(val)
-    }
-}
-impl From<FieldConversion> for Expr {
-    fn from(val: FieldConversion) -> Self {
-        Expr::FieldConversion(val)
-    }
-}
-impl From<SearchModifier> for Expr {
-    fn from(val: SearchModifier) -> Self {
-        Expr::SearchModifier(val)
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub enum FieldLike {
@@ -798,27 +579,6 @@ pub enum FieldLike {
     Alias(Alias),
 }
 
-impl From<Field> for FieldLike {
-    fn from(val: Field) -> Self {
-        FieldLike::Field(val)
-    }
-}
-impl From<Wildcard> for FieldLike {
-    fn from(val: Wildcard) -> Self {
-        FieldLike::Wildcard(val)
-    }
-}
-impl From<AliasedField> for FieldLike {
-    fn from(val: AliasedField) -> Self {
-        FieldLike::AliasedField(val)
-    }
-}
-impl From<Alias> for FieldLike {
-    fn from(val: Alias) -> Self {
-        FieldLike::Alias(val)
-    }
-}
-
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
 pub enum FieldOrAlias {
@@ -826,22 +586,6 @@ pub enum FieldOrAlias {
     Alias(Alias),
 }
 
-impl From<Field> for FieldOrAlias {
-    fn from(val: Field) -> Self {
-        FieldOrAlias::Field(val)
-    }
-}
-impl From<Alias> for FieldOrAlias {
-    fn from(val: Alias) -> Self {
-        FieldOrAlias::Alias(val)
-    }
-}
-impl From<AliasedField> for FieldOrAlias {
-    fn from(val: AliasedField) -> Self {
-        FieldOrAlias::Alias(val.into())
-    }
-}
-
 #[allow(clippy::enum_variant_names)]
 #[derive(Debug, PartialEq, Clone, Hash)]
 #[pyclass(frozen, eq, hash)]
@@ -880,47 +624,4 @@ pub enum Command {
     TopCommand(TopCommand),
     TStatsCommand(TStatsCommand),
     WhereCommand(WhereCommand),
-    // Pipeline(Pipeline),
 }
-
-// macro_rules! trivial_enum_from_type {
-//     ($cls:ident : $enum_tp:ident) => {
-//         impl From<$cls> for $enum_tp {
-//             fn from(val: $cls) -> Self {
-//                 $enum_tp::$cls(val)
-//             }
-//         }
-//     };
-// }
-
-// trivial_enum_from_type!(AddTotalsCommand: Command);
-// trivial_enum_from_type!(BinCommand: Command);
-// trivial_enum_from_type!(CollectCommand: Command);
-// trivial_enum_from_type!(ConvertCommand: Command);
-// trivial_enum_from_type!(DedupCommand: Command);
-// trivial_enum_from_type!(EvalCommand: Command);
-// trivial_enum_from_type!(EventStatsCommand: Command);
-// trivial_enum_from_type!(FieldsCommand: Command);
-// trivial_enum_from_type!(FillNullCommand: Command);
-// trivial_enum_from_type!(FormatCommand: Command);
-// trivial_enum_from_type!(HeadCommand: Command);
-// trivial_enum_from_type!(InputLookupCommand: Command);
-// trivial_enum_from_type!(JoinCommand: Command);
-// trivial_enum_from_type!(LookupCommand: Command);
-// trivial_enum_from_type!(MakeResultsCommand: Command);
-// trivial_enum_from_type!(MapCommand: Command);
-// trivial_enum_from_type!(MultiSearchCommand: Command);
-// trivial_enum_from_type!(MvCombineCommand: Command);
-// trivial_enum_from_type!(MvExpandCommand: Command);
-// trivial_enum_from_type!(RegexCommand: Command);
-// trivial_enum_from_type!(RenameCommand: Command);
-// trivial_enum_from_type!(ReturnCommand: Command);
-// trivial_enum_from_type!(RexCommand: Command);
-// trivial_enum_from_type!(SearchCommand: Command);
-// trivial_enum_from_type!(SortCommand: Command);
-// trivial_enum_from_type!(StatsCommand: Command);
-// trivial_enum_from_type!(StreamStatsCommand: Command);
-// trivial_enum_from_type!(TableCommand: Command);
-// trivial_enum_from_type!(TopCommand: Command);
-// trivial_enum_from_type!(TStatsCommand: Command);
-// trivial_enum_from_type!(WhereCommand: Command);
diff --git a/src/spl/ast_impls.rs b/src/spl/ast_impls.rs
new file mode 100644
index 0000000..bfdfee6
--- /dev/null
+++ b/src/spl/ast_impls.rs
@@ -0,0 +1,296 @@
+use crate::spl::ast::{
+    Alias, AliasedField, Binary, BoolValue, Call, Constant, DoubleValue, Expr, Field, FieldIn,
+    FieldLike, FieldOrAlias, FormattedTimeModifier, IPv4CIDR, IntValue, LeafExpr, SearchModifier,
+    SnapTime, StrValue, TimeSpan, Unary, Variable, Wildcard, FB, FC, FV,
+};
+
+impl<T: Into<bool>> From<T> for BoolValue {
+    fn from(value: T) -> Self {
+        BoolValue(value.into())
+    }
+}
+
+impl<T: Into<i64>> From<T> for IntValue {
+    fn from(value: T) -> Self {
+        IntValue(value.into())
+    }
+}
+
+impl<T: Into<f64>> From<T> for DoubleValue {
+    fn from(value: T) -> Self {
+        DoubleValue(value.into())
+    }
+}
+
+impl<T: ToString> From<T> for StrValue {
+    fn from(value: T) -> Self {
+        StrValue(value.to_string())
+    }
+}
+
+impl<S: ToString> From<S> for Field {
+    fn from(value: S) -> Field {
+        Field(value.to_string())
+    }
+}
+
+impl<S: ToString> From<S> for Wildcard {
+    fn from(value: S) -> Wildcard {
+        Wildcard(value.to_string())
+    }
+}
+
+impl<S: ToString> From<S> for Variable {
+    fn from(value: S) -> Variable {
+        Variable(value.to_string())
+    }
+}
+
+impl<S: ToString> From<S> for IPv4CIDR {
+    fn from(value: S) -> IPv4CIDR {
+        IPv4CIDR(value.to_string())
+    }
+}
+
+impl From<AliasedField> for Alias {
+    fn from(value: AliasedField) -> Self {
+        Alias {
+            expr: Box::new(value.field.into()),
+            name: value.alias,
+        }
+    }
+}
+
+impl From<TimeSpan> for Constant {
+    fn from(val: TimeSpan) -> Self {
+        Constant::TimeSpan(val)
+    }
+}
+
+impl From<BoolValue> for Constant {
+    fn from(val: BoolValue) -> Self {
+        Constant::Bool(val)
+    }
+}
+
+impl From<IntValue> for Constant {
+    fn from(val: IntValue) -> Self {
+        Constant::Int(val)
+    }
+}
+
+impl From<DoubleValue> for Constant {
+    fn from(val: DoubleValue) -> Self {
+        Constant::Double(val)
+    }
+}
+
+impl From<StrValue> for Constant {
+    fn from(val: StrValue) -> Self {
+        Constant::Str(val)
+    }
+}
+
+impl From<SnapTime> for Constant {
+    fn from(val: SnapTime) -> Self {
+        Constant::SnapTime(val)
+    }
+}
+
+impl From<Field> for Constant {
+    fn from(val: Field) -> Self {
+        Constant::Field(val)
+    }
+}
+
+impl From<Wildcard> for Constant {
+    fn from(val: Wildcard) -> Self {
+        Constant::Wildcard(val)
+    }
+}
+
+impl From<Variable> for Constant {
+    fn from(val: Variable) -> Self {
+        Constant::Variable(val)
+    }
+}
+
+impl From<IPv4CIDR> for Constant {
+    fn from(val: IPv4CIDR) -> Self {
+        Constant::IPv4CIDR(val)
+    }
+}
+
+impl From<Constant> for Expr {
+    fn from(val: Constant) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val))
+    }
+}
+
+impl From<TimeSpan> for Expr {
+    fn from(val: TimeSpan) -> Self {
+        <TimeSpan as Into<Constant>>::into(val).into()
+    }
+}
+
+impl From<BoolValue> for Expr {
+    fn from(val: BoolValue) -> Self {
+        <BoolValue as Into<Constant>>::into(val).into()
+    }
+}
+
+impl From<IntValue> for Expr {
+    fn from(val: IntValue) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<DoubleValue> for Expr {
+    fn from(val: DoubleValue) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<StrValue> for Expr {
+    fn from(val: StrValue) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<SnapTime> for Expr {
+    fn from(val: SnapTime) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<Field> for Expr {
+    fn from(val: Field) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<Wildcard> for Expr {
+    fn from(val: Wildcard) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<Variable> for Expr {
+    fn from(val: Variable) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<IPv4CIDR> for Expr {
+    fn from(val: IPv4CIDR) -> Self {
+        Expr::Leaf(LeafExpr::Constant(val.into()))
+    }
+}
+
+impl From<FV> for Expr {
+    fn from(val: FV) -> Self {
+        Expr::Leaf(LeafExpr::FV(val))
+    }
+}
+
+impl From<FB> for Expr {
+    fn from(val: FB) -> Self {
+        Expr::Leaf(LeafExpr::FB(val))
+    }
+}
+
+impl From<FC> for Expr {
+    fn from(val: FC) -> Self {
+        Expr::Leaf(LeafExpr::FC(val))
+    }
+}
+
+impl From<AliasedField> for Expr {
+    fn from(val: AliasedField) -> Self {
+        Expr::AliasedField(val)
+    }
+}
+
+impl From<Binary> for Expr {
+    fn from(val: Binary) -> Self {
+        Expr::Binary(val)
+    }
+}
+
+impl From<Unary> for Expr {
+    fn from(val: Unary) -> Self {
+        Expr::Unary(val)
+    }
+}
+
+impl From<Call> for Expr {
+    fn from(val: Call) -> Self {
+        Expr::Call(val)
+    }
+}
+
+impl From<FieldIn> for Expr {
+    fn from(val: FieldIn) -> Self {
+        Expr::FieldIn(val)
+    }
+}
+
+impl From<Alias> for Expr {
+    fn from(val: Alias) -> Self {
+        Expr::Alias(val)
+    }
+}
+
+impl From<FormattedTimeModifier> for Expr {
+    fn from(val: FormattedTimeModifier) -> Self {
+        Expr::TimeModifier(val)
+    }
+}
+
+impl From<SearchModifier> for Expr {
+    fn from(val: SearchModifier) -> Self {
+        Expr::SearchModifier(val)
+    }
+}
+
+impl From<Field> for FieldLike {
+    fn from(val: Field) -> Self {
+        FieldLike::Field(val)
+    }
+}
+
+impl From<Wildcard> for FieldLike {
+    fn from(val: Wildcard) -> Self {
+        FieldLike::Wildcard(val)
+    }
+}
+
+impl From<AliasedField> for FieldLike {
+    fn from(val: AliasedField) -> Self {
+        FieldLike::AliasedField(val)
+    }
+}
+
+impl From<Alias> for FieldLike {
+    fn from(val: Alias) -> Self {
+        FieldLike::Alias(val)
+    }
+}
+
+impl From<Field> for FieldOrAlias {
+    fn from(val: Field) -> Self {
+        FieldOrAlias::Field(val)
+    }
+}
+
+impl From<Alias> for FieldOrAlias {
+    fn from(val: Alias) -> Self {
+        FieldOrAlias::Alias(val)
+    }
+}
+
+impl From<AliasedField> for FieldOrAlias {
+    fn from(val: AliasedField) -> Self {
+        FieldOrAlias::Alias(val.into())
+    }
+}
diff --git a/src/spl/mod.rs b/src/spl/mod.rs
index 3d296f3..f7d0a26 100644
--- a/src/spl/mod.rs
+++ b/src/spl/mod.rs
@@ -1,4 +1,5 @@
 pub mod ast;
+mod ast_impls;
 pub mod macros;
 pub mod operators;
 pub(crate) mod parser;
diff --git a/src/spl/parser.rs b/src/spl/parser.rs
index bc175ee..81719a8 100644
--- a/src/spl/parser.rs
+++ b/src/spl/parser.rs
@@ -625,9 +625,7 @@ pub fn literal(input: &str) -> IResult<&str, ast::Constant> {
         map(all_consuming(str_value), ast::Constant::Str),
         map(all_consuming(variable), ast::Constant::Variable),
         map(all_consuming(relative_time), ast::Constant::SnapTime),
-        map(all_consuming(time_span), |v| {
-            ast::Constant::SplSpan(ast::SplSpan::TimeSpan(v))
-        }),
+        map(all_consuming(time_span), ast::Constant::TimeSpan),
         map(all_consuming(double), ast::Constant::Double),
         map(all_consuming(int), ast::Constant::Int),
         map(all_consuming(bool_), ast::Constant::Bool),
@@ -640,20 +638,18 @@ pub fn constant(input: &str) -> IResult<&str, ast::Constant> {
     let (remaining, content) =
         recognize(alt((double_quoted, single_quoted, token_with_extras)))(input)?;
     let (_, parsed_value) = alt((
-        map(all_consuming(ipv4_cidr), ast::Constant::IPv4CIDR),
+        into(all_consuming(ipv4_cidr)),
         map(all_consuming(ipv4_addr), |s| ast::Constant::Str(s.into())),
         map(all_consuming(ipv6_addr), |s| ast::Constant::Str(s.into())),
-        map(all_consuming(relative_time), ast::Constant::SnapTime),
-        map(all_consuming(time_span), |v| {
-            ast::Constant::SplSpan(ast::SplSpan::TimeSpan(v))
-        }),
-        map(all_consuming(wildcard), ast::Constant::Wildcard),
-        map(all_consuming(str_value), ast::Constant::Str),
-        map(all_consuming(variable), ast::Constant::Variable),
-        map(all_consuming(double), ast::Constant::Double),
-        map(all_consuming(int), ast::Constant::Int),
-        map(all_consuming(field), ast::Constant::Field),
-        map(all_consuming(bool_), ast::Constant::Bool),
+        into(all_consuming(relative_time)),
+        into(all_consuming(time_span)),
+        into(all_consuming(wildcard)),
+        into(all_consuming(str_value)),
+        into(all_consuming(variable)),
+        into(all_consuming(double)),
+        into(all_consuming(int)),
+        into(all_consuming(field)),
+        into(all_consuming(bool_)),
     ))(content)?;
     Ok((remaining, parsed_value))
 }
@@ -1486,7 +1482,13 @@ pub fn time_opts(input: &str) -> IResult<&str, Vec<ast::Expr>> {
         pair(time_format, space_separated_list1(time_modifier)),
         |(fmt, mods)| {
             mods.into_iter()
-                .map(|time_mod| ast::Expr::TimeModifier(fmt.into(), time_mod))
+                .map(|time_modifier| {
+                    ast::FormattedTimeModifier {
+                        format: fmt.into(),
+                        time_modifier,
+                    }
+                    .into()
+                })
                 .collect()
         },
     )(input)
@@ -2064,10 +2066,10 @@ mod tests {
                         },
                         ast::FC {
                             field: "h".into(),
-                            value: ast::Constant::SplSpan(ast::SplSpan::TimeSpan(ast::TimeSpan {
+                            value: ast::Constant::TimeSpan(ast::TimeSpan {
                                 value: -15,
                                 scale: "minutes".to_string()
-                            }))
+                            })
                         },
                         ast::FC {
                             field: "i".into(),
diff --git a/src/spl/python.rs b/src/spl/python.rs
index 33677a7..0460f10 100644
--- a/src/spl/python.rs
+++ b/src/spl/python.rs
@@ -30,22 +30,6 @@ macro_rules! impl_pyclass {
             }
         }
     };
-    ($name: path {$(|$arg: ident : $arg_tp: ty| $conv: expr),*}) => {
-        #[pymethods]
-        impl $name {
-            #[allow(clippy::too_many_arguments)]
-            #[new]
-            fn new($( $arg: $arg_tp ),*) -> Self {
-                Self { $( $arg : (|$arg: $arg_tp| $conv)($arg) ),* }
-            }
-
-            fn __repr__(&self) -> String {
-                format!("{:?}", self)
-            }
-
-            $other
-        }
-    };
 }
 
 pub(crate) use impl_pyclass;
@@ -55,6 +39,10 @@ impl_pyclass!(ast::BoolValue { bool });
 impl_pyclass!(ast::IntValue { i64 });
 impl_pyclass!(ast::StrValue { String });
 impl_pyclass!(ast::DoubleValue { f64 });
+impl_pyclass!(ast::TimeSpan {
+    value: i64,
+    scale: String
+});
 impl_pyclass!(ast::SnapTime { span: Option<ast::TimeSpan>, snap: String, snap_offset: Option<ast::TimeSpan> });
 impl_pyclass!(ast::Field { String });
 impl_pyclass!(ast::Wildcard { String });
@@ -157,6 +145,7 @@ pub fn ast(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<ast::IntValue>()?;
     m.add_class::<ast::StrValue>()?;
     m.add_class::<ast::DoubleValue>()?;
+    m.add_class::<ast::TimeSpan>()?;
     m.add_class::<ast::SnapTime>()?;
     m.add_class::<ast::Field>()?;
     m.add_class::<ast::Wildcard>()?;
@@ -205,7 +194,6 @@ pub fn ast(m: &Bound<'_, PyModule>) -> PyResult<()> {
     m.add_class::<crate::commands::cmd_map::spl::MapCommand>()?;
     m.add_class::<ast::Pipeline>()?;
 
-    m.add_class::<ast::SplSpan>()?;
     m.add_class::<ast::Constant>()?;
     m.add_class::<ast::LeafExpr>()?;
     m.add_class::<ast::Expr>()?;