diff --git a/common/CMakeLists.txt b/common/CMakeLists.txt
index abb7612c2..cb0f075e7 100644
--- a/common/CMakeLists.txt
+++ b/common/CMakeLists.txt
@@ -32,10 +32,11 @@ add_library(common
         dma/dma_copy.cpp
         dma/dma.cpp
         dma/gs.cpp
-        formatter/config/rule_config.cpp
         formatter/formatter_tree.cpp
         formatter/formatter.cpp
-        formatter/formatting_rules.cpp
+        formatter/formatter_tree.cpp
+        formatter/rules/formatting_rules.cpp
+        formatter/rules/rule_config.cpp
         global_profiler/GlobalProfiler.cpp
         goos/Interpreter.cpp
         goos/Object.cpp
diff --git a/common/formatter/config/rule_config.cpp b/common/formatter/config/rule_config.cpp
deleted file mode 100644
index 4b6e29d1d..000000000
--- a/common/formatter/config/rule_config.cpp
+++ /dev/null
@@ -1,10 +0,0 @@
-#include "rule_config.h"
-
-namespace formatter_rules {
-namespace config {
-
-// TODO - populate these more
-
-std::unordered_map<std::string, FormConfiguration> opengoal_form_config = {};
-}  // namespace config
-}  // namespace formatter_rules
diff --git a/common/formatter/config/rule_config.h b/common/formatter/config/rule_config.h
deleted file mode 100644
index da1d1b19e..000000000
--- a/common/formatter/config/rule_config.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#pragma once
-
-#include <memory>
-#include <string>
-#include <unordered_map>
-#include <vector>
-
-#include "common/formatter/formatting_rules.h"
-
-namespace formatter_rules {
-namespace config {
-struct FormConfiguration {
-  bool force_hang = false;
-  int start_hang_at_index = 0;
-};
-
-extern std::unordered_map<std::string, FormConfiguration> opengoal_form_config;
-}  // namespace config
-}  // namespace formatter_rules
diff --git a/common/formatter/formatter.cpp b/common/formatter/formatter.cpp
index ce0a41e14..99b3b7b9d 100644
--- a/common/formatter/formatter.cpp
+++ b/common/formatter/formatter.cpp
@@ -2,6 +2,7 @@
 
 #include "formatter_tree.h"
 
+#include "common/log/log.h"
 #include "common/util/FileUtil.h"
 #include "common/util/string_util.h"
 
@@ -15,9 +16,11 @@ extern "C" {
 extern const TSLanguage* tree_sitter_opengoal();
 }
 
-std::string apply_formatting(const FormatterTreeNode& curr_node,
-                             std::string output,
-                             int tree_depth = 0) {
+std::string apply_formatting(
+    const FormatterTreeNode& curr_node,
+    std::string output,
+    std::optional<formatter_rules::config::FormFormattingConfig> form_element_config) {
+  using namespace formatter_rules;
   if (!curr_node.token && curr_node.refs.empty()) {
     return output;
   }
@@ -34,33 +37,69 @@ std::string apply_formatting(const FormatterTreeNode& curr_node,
 
   bool inline_form = false;
   // Also check if the form should be constant-paired
-  const bool constant_pair_form =
-      formatter_rules::constant_pairs::form_should_be_constant_paired(curr_node);
+  const bool constant_pair_form = constant_pairs::form_should_be_constant_paired(curr_node);
   if (!constant_pair_form) {
     // Determine if the form should be inlined or hung/flowed
     // TODO - this isn't entirely accurate, needs current cursor positioning (which is tricky
     // because recursion!)
-    inline_form = formatter_rules::indent::form_can_be_inlined(curr_form, curr_node);
+    inline_form = indent::form_can_be_inlined(curr_form, curr_node);
   }
+  const bool flowing = indent::should_form_flow(curr_node, inline_form);
+  std::optional<formatter_rules::config::FormFormattingConfig> form_config;
+  if (!curr_node.refs.empty() && curr_node.refs.at(0).token) {
+    const auto& form_head = curr_node.refs.at(0).token;
+    if (form_head && config::opengoal_form_config.find(form_head.value()) !=
+                         config::opengoal_form_config.end()) {
+      form_config = config::opengoal_form_config.at(form_head.value());
+    }
+  }
+  // TODO - might want to make some kind of per-form config struct, simplify the passing around of
+  // info below
   for (int i = 0; i < curr_node.refs.size(); i++) {
     const auto& ref = curr_node.refs.at(i);
-    // Append a newline if needed
-    if (!inline_form) {
-      formatter_rules::indent::append_newline(curr_form, ref, curr_node, tree_depth, i,
-                                              constant_pair_form);
+    // Figure out if the element should be inlined or not
+    bool inline_element = inline_form;
+    if (indent::inline_form_element(curr_node, i)) {
+      inline_element = indent::inline_form_element(curr_node, i).value();
     }
+    // Append a newline if needed
+    // TODO - cleanup / move
+    bool is_binding_list = false;
+    bool force_newline = false;
+    bool override_force_flow = false;
+    if (form_config) {
+      force_newline = std::find(form_config->force_newline_at_indices.begin(),
+                                form_config->force_newline_at_indices.end(),
+                                i) != form_config->force_newline_at_indices.end();
+      // Check if it's a small enough binding list, if so we don't force a newline if the element
+      // can be inlined
+      if (inline_element && i > 0 && form_config->bindings_at_index == i - 1 &&
+          curr_node.refs.at(i - 1).refs.size() < form_config->allow_inlining_if_size_less_than) {
+        force_newline = false;
+        override_force_flow = true;
+      }
+      is_binding_list = form_config->bindings_at_index == i;
+    }
+
+    if (!curr_node.metadata.is_top_level &&
+        (!inline_element || is_binding_list || force_newline ||
+         (form_element_config && form_element_config->force_flow))) {
+      indent::append_newline(curr_form, ref, curr_node, i, flowing, constant_pair_form,
+                             (form_element_config && form_element_config->force_flow));
+    }
+    // TODO - indent the line (or don't)
     // Either print the element's token, or recursively format it as well
     if (ref.token) {
       // TODO depth hard-coded to 1, i think this can be removed, since
       // forms are always done bottom-top recursively, they always act
       // independently as if it was the shallowest depth
-      if (!inline_form) {
-        formatter_rules::indent::flow_line(curr_form, ref, curr_node, 1, i);
+      if (!inline_element || force_newline) {
+        indent::indent_line(curr_form, ref, curr_node, 1, i, flowing);
       }
       if (ref.metadata.node_type == "comment" && ref.metadata.is_inline) {
         curr_form += " " + ref.token.value();
       } else if (ref.metadata.node_type == "block_comment") {
-        curr_form += formatter_rules::comments::format_block_comment(ref.token.value());
+        curr_form += comments::format_block_comment(ref.token.value());
       } else {
         curr_form += ref.token.value();
       }
@@ -68,9 +107,20 @@ std::string apply_formatting(const FormatterTreeNode& curr_node,
         curr_form += " ";
       }
     } else {
-      auto formatted_form = apply_formatting(ref, "", tree_depth + 1);
-      if (!curr_node.metadata.is_top_level && !inline_form) {
-        formatter_rules::indent::hang_lines(formatted_form, ref, curr_node, constant_pair_form);
+      // See if the item at this position has specific formatting
+      std::optional<formatter_rules::config::FormFormattingConfig> config = {};
+      std::string formatted_form;
+      if (form_config && form_config->index_configs.find(i) != form_config->index_configs.end()) {
+        formatted_form = apply_formatting(ref, "", *form_config->index_configs.at(i));
+      } else {
+        formatted_form = apply_formatting(ref, "", {});
+      }
+      // TODO - align inner lines only
+      if (!curr_node.metadata.is_top_level) {
+        indent::align_lines(
+            formatted_form, ref, curr_node, constant_pair_form, flowing,
+            (!override_force_flow && form_config && i >= form_config->start_flow_at_index),
+            inline_element);
       }
       curr_form += formatted_form;
       if (!curr_node.metadata.is_top_level) {
@@ -78,7 +128,7 @@ std::string apply_formatting(const FormatterTreeNode& curr_node,
       }
     }
     // Handle blank lines at the top level, skip if it's the final element
-    formatter_rules::blank_lines::separate_by_newline(curr_form, curr_node, ref, i);
+    blank_lines::separate_by_newline(curr_form, curr_node, ref, i);
   }
   if (!curr_node.metadata.is_top_level) {
     curr_form = str_util::rtrim(curr_form) + ")";
@@ -104,8 +154,13 @@ std::optional<std::string> formatter::format_code(const std::string& source) {
     return std::nullopt;
   }
 
-  const auto formatting_tree = FormatterTree(source, root_node);
-  std::string formatted_code = apply_formatting(formatting_tree.root, "");
+  try {
+    const auto formatting_tree = FormatterTree(source, root_node);
+    std::string formatted_code = apply_formatting(formatting_tree.root, "", {});
+    return formatted_code;
+  } catch (std::exception& e) {
+    lg::error("Unable to format code - {}", e.what());
+  }
 
-  return formatted_code;
+  return std::nullopt;
 }
diff --git a/common/formatter/formatter.h b/common/formatter/formatter.h
index 83a332a78..0ce2a11e2 100644
--- a/common/formatter/formatter.h
+++ b/common/formatter/formatter.h
@@ -3,7 +3,8 @@
 #include <optional>
 #include <string>
 
-#include "formatting_rules.h"
+#include "common/formatter/rules/formatting_rules.h"
+#include "common/formatter/rules/rule_config.h"
 
 #include "tree_sitter/api.h"
 
diff --git a/common/formatter/formatter_tree.cpp b/common/formatter/formatter_tree.cpp
index 8d96e8b0b..4bfbc28bc 100644
--- a/common/formatter/formatter_tree.cpp
+++ b/common/formatter/formatter_tree.cpp
@@ -2,8 +2,6 @@
 
 #include "common/util/string_util.h"
 
-#include "config/rule_config.h"
-
 #include "third-party/fmt/core.h"
 
 std::string get_source_code(const std::string& source, const TSNode& node) {
diff --git a/common/formatter/formatter_tree.h b/common/formatter/formatter_tree.h
index d0165a45d..c3eefd4cd 100644
--- a/common/formatter/formatter_tree.h
+++ b/common/formatter/formatter_tree.h
@@ -31,6 +31,7 @@ class FormatterTreeNode {
     bool is_comment = false;
     bool is_inline = false;
     int num_blank_lines_following = 0;
+    bool is_binding_list = false;  // TODO set this
   };
   std::vector<FormatterTreeNode> refs;
   Metadata metadata;
@@ -41,6 +42,8 @@ class FormatterTreeNode {
   FormatterTreeNode() = default;
   FormatterTreeNode(const std::string& source, const TSNode& node);
   FormatterTreeNode(const Metadata& _metadata) : metadata(_metadata){};
+
+  bool is_list() const { return token.has_value(); }
 };
 
 // A FormatterTree has a very simple and crude tree structure where:
diff --git a/common/formatter/formatting_rules.cpp b/common/formatter/rules/formatting_rules.cpp
similarity index 58%
rename from common/formatter/formatting_rules.cpp
rename to common/formatter/rules/formatting_rules.cpp
index 4171d31fa..6078b68dd 100644
--- a/common/formatter/formatting_rules.cpp
+++ b/common/formatter/rules/formatting_rules.cpp
@@ -2,6 +2,8 @@
 
 #include <set>
 
+#include "rule_config.h"
+
 #include "common/util/string_util.h"
 
 #include "third-party/fmt/core.h"
@@ -196,27 +198,89 @@ bool form_contains_comment(const FormatterTreeNode& node) {
   return false;
 }
 
-bool form_can_be_inlined(std::string& curr_text, const FormatterTreeNode& node) {
-  // Two main checks:
-  // - first, is the form too long to fit on a line TODO - increase accuracy here
-  if (form_exceed_line_width(curr_text, node, 0)) {
+bool form_can_be_inlined(const std::string& curr_text, const FormatterTreeNode& list_node) {
+  // is the form too long to fit on a line TODO - increase accuracy here
+  if (form_exceed_line_width(curr_text, list_node, 0)) {
     return false;
   }
-  // - second, are there any comments? (inlined or not, doesn't matter)
-  if (form_contains_comment(node)) {
+  // are there any comments? (inlined or not, doesn't matter)
+  if (form_contains_comment(list_node)) {
     return false;
   }
   return true;
 }
 
+bool should_form_flow(const FormatterTreeNode& list_node, const bool inlining_form) {
+  if (form_contains_comment(list_node)) {
+    return true;
+  }
+  // does the form begin with a constant (a list of content elements)
+  if (!inlining_form && !list_node.refs.empty() &&
+      constant_types.find(list_node.refs.at(0).metadata.node_type) != constant_types.end()) {
+    return true;
+  }
+
+  // TODO - make a function to make grabbing this metadata easier...
+  // TODO - honestly should just have an is_list metadata
+  if (!list_node.refs.empty() && !list_node.refs.at(0).token) {
+    // if the first element is a comment, force a flow
+    if (list_node.refs.size() > 1 && list_node.refs.at(1).metadata.is_comment) {
+      return true;
+    }
+    const auto& form_head = list_node.refs.at(0).token;
+    // See if we have any configuration for this form
+    if (form_head && config::opengoal_form_config.find(form_head.value()) !=
+                         config::opengoal_form_config.end()) {
+      const auto& form_config = config::opengoal_form_config.at(form_head.value());
+      return form_config.force_flow;
+    }
+  }
+
+  // TODO - cleanup, might be inside a let
+  /*if (!containing_form.refs.empty() && containing_form.refs.at(0).token) {
+    const auto& form_head = containing_form.refs.at(0).token;
+    if (form_head && config::opengoal_form_config.find(form_head.value()) !=
+                         config::opengoal_form_config.end()) {
+      const auto& form_config = config::opengoal_form_config.at(form_head.value());
+      if (form_config.force_flow) {
+        return true;
+      }
+    }
+  }*/
+
+  return false;
+}
+
+std::optional<bool> inline_form_element(const FormatterTreeNode& list_node, const int index) {
+  // TODO - honestly should just have an is_list metadata
+  if (list_node.refs.empty() || !list_node.refs.at(0).token) {
+    return std::nullopt;
+  }
+  const auto& form_head = list_node.refs.at(0).token;
+  // See if we have any configuration for this form
+  if (form_head &&
+      config::opengoal_form_config.find(form_head.value()) != config::opengoal_form_config.end()) {
+    const auto& form_config = config::opengoal_form_config.at(form_head.value());
+    if (form_config.inline_until_index != -1) {
+      return index < form_config.inline_until_index;
+    }
+  }
+  return std::nullopt;
+}
+
 void append_newline(std::string& curr_text,
                     const FormatterTreeNode& node,
                     const FormatterTreeNode& containing_node,
-                    const int depth,
                     const int index,
-                    const bool constant_pair_form) {
+                    const bool flowing,
+                    const bool constant_pair_form,
+                    const bool force_newline) {
+  if (force_newline && index >= 1 || (node.metadata.is_comment && !node.metadata.is_inline)) {
+    curr_text = str_util::rtrim(curr_text) + "\n";
+    return;
+  }
   if (index <= 0 || containing_node.metadata.is_top_level ||
-      (node.metadata.is_comment && node.metadata.is_inline)) {
+      (node.metadata.is_comment && node.metadata.is_inline) || (!flowing && index <= 1)) {
     return;
   }
   // Check if it's a constant pair
@@ -227,11 +291,12 @@ void append_newline(std::string& curr_text,
   curr_text = str_util::rtrim(curr_text) + "\n";
 }
 
-void flow_line(std::string& curr_text,
-               const FormatterTreeNode& node,
-               const FormatterTreeNode& containing_node,
-               const int depth,
-               const int index) {
+void indent_line(std::string& curr_text,
+                 const FormatterTreeNode& node,
+                 const FormatterTreeNode& containing_node,
+                 const int depth,
+                 const int index,
+                 const bool flowing) {
   if (node.metadata.is_top_level || (node.metadata.is_inline && node.metadata.is_comment)) {
     return;
   }
@@ -240,42 +305,89 @@ void flow_line(std::string& curr_text,
   if (constant_pairs::is_element_second_in_constant_pair(containing_node, node, index)) {
     return;
   }
-  if (index > 0) {
-    // If the first element in the list is a constant, we only indent with 1 space instead
-    if (constant_types.find(containing_node.refs.at(0).metadata.node_type) !=
-        constant_types.end()) {
-      curr_text += str_util::repeat(depth, " ");
-    } else {
-      curr_text += str_util::repeat(depth, "  ");
-    }
+  // If the first element in the list is a constant, we only indent with 1 space instead
+  if (index > 0 &&
+      constant_types.find(containing_node.refs.at(0).metadata.node_type) != constant_types.end()) {
+    curr_text += str_util::repeat(depth, " ");
+  } else if (index > 0 && flowing) {
+    curr_text += str_util::repeat(depth, "  ");
+  } else if (index > 1 && !flowing) {
+    curr_text += str_util::repeat(containing_node.refs.at(0).token.value().length() + 2, " ");
   }
 }
 
-void hang_lines(std::string& text,
-                const FormatterTreeNode& node,
-                const FormatterTreeNode& containing_node,
-                const bool constant_pair_form) {
-  const auto lines = str_util::split(text);
-  // TODO - unsafe (breaks on a list of lists)
-  int alignment_width = 2;
-  if (constant_pair_form &&
-      constant_types.find(containing_node.refs.at(0).metadata.node_type) != constant_types.end()) {
-    alignment_width = 3;
+// Recursively iterate through the node until we hit a token
+int length_to_hang(const FormatterTreeNode& node, int length) {
+  if (node.token || node.refs.at(0).token) {
+    return length;
+  }
+  return length_to_hang(node.refs.at(0), length + 1);
+}
+
+void align_lines(std::string& text,
+                 const FormatterTreeNode& node,
+                 const FormatterTreeNode& containing_node,
+                 const bool constant_pair_form,
+                 const bool flowing,
+                 const bool force_flow,
+                 const bool inline_element) {
+  const auto lines = str_util::split(text);
+  int start_index = 0;
+  if (inline_element) {
+    start_index = 1;
+  }
+  int alignment_width = 2;
+  if (force_flow) {
+    start_index = 0;
+  } else if (constant_pair_form &&
+             constant_types.find(containing_node.refs.at(0).metadata.node_type) !=
+                 constant_types.end()) {
+    start_index = 0;
+    alignment_width = 3;
+  } else if (!flowing) {
+    // If the form has a token (it's a normal list)
+    if (containing_node.refs.at(0).token) {
+      alignment_width = length_to_hang(containing_node.refs.at(1),
+                                       containing_node.refs.at(0).token.value().length()) +
+                        1;
+      if (!node.token) {
+        alignment_width++;
+      }
+    } else {
+      // otherwise, it's a list of lists
+      alignment_width = 1;
+    }
+  } else if (!node.token) {
+    // If it's a list of lists
+    alignment_width = 1;
   }
-  // TODO - implement hanging
-  // always hang unless flowing is "better" (this is the hard part)
-  /*else if (containing_node.metadata.multiple_elements_first_line) {
-    alignment_width = containing_node.refs.at(0).token.value().length() + 2;
-  }*/
   std::string aligned_form = "";
   for (int i = 0; i < lines.size(); i++) {
-    aligned_form += str_util::repeat(alignment_width, " ") + lines.at(i);
+    if (i >= start_index) {
+      aligned_form += str_util::repeat(alignment_width, " ");
+    }
+    aligned_form += lines.at(i);
     if (i != lines.size() - 1) {
       aligned_form += "\n";
     }
   }
-  text = aligned_form;
+  if (!aligned_form.empty()) {
+    text = aligned_form;
+  }
 }
 }  // namespace indent
+namespace let {
+
+bool can_be_inlined(const FormatterTreeNode& form) {
+  // Check a variety of things specific to `let` style forms (ones with bindings)
+  // - does the binding list have more than one binding?
+  const auto& bindings = form.refs.at(1);  // TODO - assuming
+  if (bindings.refs.size() > 1) {
+    return false;
+  }
+  return true;
+}
+
+}  // namespace let
 
 }  // namespace formatter_rules
diff --git a/common/formatter/formatting_rules.h b/common/formatter/rules/formatting_rules.h
similarity index 60%
rename from common/formatter/formatting_rules.h
rename to common/formatter/rules/formatting_rules.h
index 26bd06a7e..3331cfa91 100644
--- a/common/formatter/formatting_rules.h
+++ b/common/formatter/rules/formatting_rules.h
@@ -2,7 +2,7 @@
 
 #include <string>
 
-#include "formatter_tree.h"
+#include "common/formatter/formatter_tree.h"
 
 namespace formatter_rules {
 // The formatter will try to collapse as much space as possible in the top-level, this means
@@ -85,30 +85,61 @@ bool form_should_be_constant_paired(const FormatterTreeNode& node);
 // Additionally, if the head of the form is a constant we `flow` with an indent of `1` instead of
 // `2`
 //
-// TODO: - incorporate more heuristics here, explore both a hang and flow approach to see which is
-// better
+// By default, we always hang unless:
+// - the head-form overrides the configuration
+// - TODO it will use more lines than the flow approach
 //
 // Reference - https://github.com/kkinnear/zprint/blob/main/doc/options/indent.md
 namespace indent {
 const static int line_width_target = 120;
 
-bool form_can_be_inlined(std::string& curr_text, const FormatterTreeNode& node);
+bool form_can_be_inlined(const std::string& curr_text, const FormatterTreeNode& curr_node);
+
+// TODO - right now this is very primitive in that it only checks against our hard-coded config
+// eventually make this explore both routes and determine which is best
+// Also factor in distance from the gutter (theres some zprint rationale somewhere on this)
+bool should_form_flow(const FormatterTreeNode& list_node, const bool inlining_form);
+std::optional<bool> inline_form_element(const FormatterTreeNode& list_node, const int index);
 
 void append_newline(std::string& curr_text,
                     const FormatterTreeNode& node,
                     const FormatterTreeNode& containing_node,
-                    const int depth,
                     const int index,
-                    const bool constant_pair_form);
-void flow_line(std::string& curr_text,
-               const FormatterTreeNode& node,
-               const FormatterTreeNode& containing_node,
-               const int depth,
-               const int index);
-void hang_lines(std::string& text,
-                const FormatterTreeNode& node,
-                const FormatterTreeNode& containing_node,
-                const bool constant_pair_form);
+                    const bool flowing,
+                    const bool constant_pair_form,
+                    const bool force_newline);
+void indent_line(std::string& curr_text,
+                 const FormatterTreeNode& node,
+                 const FormatterTreeNode& containing_node,
+                 const int depth,
+                 const int index,
+                 const bool flowing);
+void align_lines(std::string& text,
+                 const FormatterTreeNode& node,
+                 const FormatterTreeNode& containing_node,
+                 const bool constant_pair_form,
+                 const bool flowing,
+                 const bool force_flow,
+                 const bool inline_element);
 
 }  // namespace indent
+
+// Let forms fall into two main categories
+// - Ones that can be entirely inlined
+// - Ones that cannot
+//
+// Single line let forms:
+// - If there is a single binding, let it continue to be one line
+// - otherwise, flow it just as a multi-line let would be done
+//
+// For multi-line let forms, the difficulty is how to format the binding:
+// - align the bindings to within the binding list (single indent space)
+// - always format the binding value on the same line as the binding, no new lines
+// - forms inside the let binding are flowed
+//
+// Reference - https://github.com/kkinnear/zprint/blob/main/doc/options/let.md
+namespace let {
+// TODO - like above, factor in current cursor position
+bool can_be_inlined(const FormatterTreeNode& form);
+}  // namespace let
 }  // namespace formatter_rules
diff --git a/common/formatter/rules/rule_config.cpp b/common/formatter/rules/rule_config.cpp
new file mode 100644
index 000000000..9a7e8d206
--- /dev/null
+++ b/common/formatter/rules/rule_config.cpp
@@ -0,0 +1,34 @@
+#include "rule_config.h"
+
+namespace formatter_rules {
+namespace config {
+
+// TODO - populate these more
+
+// TODO - this could be greatly simplified with C++20's designated initialization
+FormFormattingConfig new_flow_rule(int start_index) {
+  FormFormattingConfig cfg;
+  cfg.force_flow = true;
+  cfg.start_flow_at_index = start_index;
+  cfg.inline_until_index = start_index;
+  return cfg;
+}
+
+FormFormattingConfig new_binding_rule() {
+  FormFormattingConfig cfg;
+  cfg.start_flow_at_index = 2;
+  cfg.bindings_at_index = 1;
+  cfg.force_flow = true;
+  cfg.force_newline_at_indices = {2};
+  cfg.allow_inlining_if_size_less_than = 2;
+  auto binding_list_config = std::make_shared<FormFormattingConfig>();
+  binding_list_config->force_flow = true;
+  cfg.index_configs.emplace(1, binding_list_config);
+  return cfg;
+}
+
+const std::unordered_map<std::string, FormFormattingConfig> opengoal_form_config = {
+    {"defun", new_flow_rule(3)},
+    {"let", new_binding_rule()}};
+}  // namespace config
+}  // namespace formatter_rules
diff --git a/common/formatter/rules/rule_config.h b/common/formatter/rules/rule_config.h
new file mode 100644
index 000000000..fc225256a
--- /dev/null
+++ b/common/formatter/rules/rule_config.h
@@ -0,0 +1,28 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "common/formatter/rules/formatting_rules.h"
+
+namespace formatter_rules {
+namespace config {
+struct FormFormattingConfig {
+  bool force_hang = false;
+  bool force_flow = false;
+  std::optional<int> allow_inlining_if_size_less_than = {};
+  int start_hang_at_index = 0;
+  int start_flow_at_index = 0;
+  int inline_until_index = -1;
+  std::optional<int> bindings_at_index = {};
+  std::optional<int> skip_newlines_until_index = {};
+  std::vector<int> force_newline_at_indices = {};
+  bool bindings_force_newlines = false;
+  std::unordered_map<int, std::shared_ptr<FormFormattingConfig>> index_configs = {};
+};
+
+extern const std::unordered_map<std::string, FormFormattingConfig> opengoal_form_config;
+}  // namespace config
+}  // namespace formatter_rules
diff --git a/common/util/string_util.cpp b/common/util/string_util.cpp
index 492753902..bb56af89a 100644
--- a/common/util/string_util.cpp
+++ b/common/util/string_util.cpp
@@ -46,8 +46,6 @@ std::string ltrim(const std::string& s) {
   return (start == std::string::npos) ? "" : s.substr(start);
 }
 
-// TODO - used a lot in formatting, and its slow because i bet it iterates from the start and not
-// the end
 std::string rtrim(const std::string& s) {
   size_t end = s.find_last_not_of(WHITESPACE);
   return (end == std::string::npos) ? "" : s.substr(0, end + 1);
diff --git a/test/common/formatter/corpus/indent-hang.test.gc b/test/common/formatter/corpus/indent-hang.test.gc
deleted file mode 100644
index e69de29bb..000000000
diff --git a/test/common/formatter/corpus/indent-flow.test.gc b/test/common/formatter/corpus/indent.test.gc
similarity index 62%
rename from test/common/formatter/corpus/indent-flow.test.gc
rename to test/common/formatter/corpus/indent.test.gc
index 5b73c504d..26ff87e5b 100644
--- a/test/common/formatter/corpus/indent-flow.test.gc
+++ b/test/common/formatter/corpus/indent.test.gc
@@ -6,12 +6,10 @@ Basic Nested Form
 
 ---
 
-(println
-  "hello"
-  (println
-    "world"
-    "world2"
-    "very-long-formvery-long-formvery-long-formvery-long-formvery-long-formvery-long-formvery-long-form"))
+(println "hello"
+         (println "world"
+                  "world2"
+                  "very-long-formvery-long-formvery-long-formvery-long-formvery-long-formvery-long-formvery-long-form"))
 
 ===
 Multiple Top Level Forms
@@ -58,3 +56,14 @@ Single Item Form
 
 (println)
 
+===
+defun - No Docstring
+===
+
+(defun test-function ((arg0 string))
+  (println arg0))
+
+---
+
+(defun test-function ((arg0 string))
+  (println arg0))
diff --git a/test/common/formatter/corpus/let.test.gc b/test/common/formatter/corpus/let.test.gc
new file mode 100644
index 000000000..db16d46eb
--- /dev/null
+++ b/test/common/formatter/corpus/let.test.gc
@@ -0,0 +1,24 @@
+===
+Single Binding - Inlinable
+===
+
+(let ((a 1))
+  (+ a b))
+
+---
+
+(let ((a 1)) (+ a b))
+
+===
+Multiple Bindings
+===
+
+(let ((a 1)
+   (b 2))
+  (+ a b))
+
+---
+
+(let ((a 1)
+      (b 2))
+  (+ a b))
diff --git a/test/common/formatter/corpus/lists.test.gc b/test/common/formatter/corpus/lists.test.gc
new file mode 100644
index 000000000..de64bdafe
--- /dev/null
+++ b/test/common/formatter/corpus/lists.test.gc
@@ -0,0 +1,24 @@
+===
+Constant List
+===
+
+(1 2 3 4)
+
+---
+
+(1 2 3 4)
+
+===
+Constant List - Too Long to Inline
+===
+
+(1111111111111 2222222222222222 3333333333333333333333333 444444444444444444444444444 555555555555555555555555555555555 666666666666666666666666666666666666666)
+
+---
+
+(1111111111111
+ 2222222222222222
+ 3333333333333333333333333
+ 444444444444444444444444444
+ 555555555555555555555555555555555
+ 666666666666666666666666666666666666666)
diff --git a/test/common/formatter/test_formatter.cpp b/test/common/formatter/test_formatter.cpp
index ee3194e57..fa1f7c83d 100644
--- a/test/common/formatter/test_formatter.cpp
+++ b/test/common/formatter/test_formatter.cpp
@@ -122,27 +122,31 @@ bool run_tests(const fs::path& file_path, const bool only_important_tests) {
 }
 
 bool find_and_run_tests() {
-  // Enumerate test files
-  const auto test_files = file_util::find_files_recursively(
-      file_util::get_file_path({"test/common/formatter/corpus"}), std::regex("^.*\.test.gc$"));
-  bool failed = false;
-  // First do a pass to see if any tests are meant to be prioritized for debugging
-  bool only_important_tests = false;
-  for (const auto& file : test_files) {
-    only_important_tests = has_important_tests(file);
-    if (only_important_tests) {
-      break;
+  try {
+    // Enumerate test files
+    const auto test_files = file_util::find_files_recursively(
+        file_util::get_file_path({"test/common/formatter/corpus"}), std::regex("^.*\.test.gc$"));
+    bool failed = false;
+    // First do a pass to see if any tests are meant to be prioritized for debugging
+    bool only_important_tests = false;
+    for (const auto& file : test_files) {
+      only_important_tests = has_important_tests(file);
+      if (only_important_tests) {
+        break;
+      }
     }
-  }
-  for (const auto& file : test_files) {
-    // don't fail fast, but any failure means we return false
-    if (failed) {
-      run_tests(file, only_important_tests);
-    } else {
-      failed = run_tests(file, only_important_tests);
+    for (const auto& file : test_files) {
+      // don't fail fast, but any failure means we return false
+      if (failed) {
+        run_tests(file, only_important_tests);
+      } else {
+        failed = run_tests(file, only_important_tests);
+      }
     }
+    return !failed;
+  } catch (std::exception& e) {
+    return false;
   }
-  return !failed;
 }
 
 TEST(Formatter, FormatterTests) {