From 3c23785b4645041f2c15d6e238df7375ecad8c72 Mon Sep 17 00:00:00 2001
From: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>
Date: Tue, 6 Oct 2026 10:19:50 -0700
Subject: [PATCH] make syntax highlighting colors configurable

Read the keyword, literal, enclosed, and error colors from
config :sql, :syntax_colors with Application.compile_env, falling back
to the current IO.ANSI defaults. The reset sequence stays fixed.

Fixes #26

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019wSaUMZrtm6XSzwEcxavkv
---
 CHANGELOG.md   |  5 +++++
 README.md      | 12 ++++++++++++
 lib/format.ex  |  8 ++++----
 lib/inspect.ex |  2 +-
 4 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9b69898..9432695 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,11 @@
 
 # Changelog
 
+## Unreleased
+
+### Enhancement
+ - Syntax highlighting colors are configurable with `config :sql, :syntax_colors`.
+
 ## v0.6.0 (2026-10-06)
 
 ### Enhancement
diff --git a/README.md b/README.md
index 912b0a0..6f52d4f 100644
--- a/README.md
+++ b/README.md
@@ -119,6 +119,18 @@ end
   [%User{id: 1, email: "john@example.com"}, %User{id: 2, email: "jane@example.com"}]
 ```
 
+## Syntax highlighting
+
+Override keyword, literal, enclosed, and error colors in `config.exs`:
+
+```elixir
+config :sql, :syntax_colors,
+  keyword: IO.ANSI.magenta(),
+  literal: IO.ANSI.yellow(),
+  enclosed: IO.ANSI.green(),
+  error: IO.ANSI.red()
+```
+
 ## Compile time warning
 Run `mix sql.get` to generate your `sql.lock` file for error reporting.
 
diff --git a/lib/format.ex b/lib/format.ex
index 9d92a07..c46f314 100644
--- a/lib/format.ex
+++ b/lib/format.ex
@@ -5,11 +5,11 @@ defmodule SQL.Format do
   @moduledoc false
   @moduledoc since: "0.4.0"
 
-  @error IO.ANSI.red()
+  @error Application.compile_env(:sql, [:syntax_colors, :error], IO.ANSI.red())
   @reset IO.ANSI.reset()
-  @keyword IO.ANSI.magenta()
-  @literal IO.ANSI.yellow()
-  @enclosed IO.ANSI.green()
+  @keyword Application.compile_env(:sql, [:syntax_colors, :keyword], IO.ANSI.magenta())
+  @literal Application.compile_env(:sql, [:syntax_colors, :literal], IO.ANSI.yellow())
+  @enclosed Application.compile_env(:sql, [:syntax_colors, :enclosed], IO.ANSI.green())
 
   @compile {:inline, indention: 3, newline: 2, pad: 1, keyword: 2, color: 3}
 
diff --git a/lib/inspect.ex b/lib/inspect.ex
index fafd56d..acf843d 100644
--- a/lib/inspect.ex
+++ b/lib/inspect.ex
@@ -4,7 +4,7 @@
 defmodule SQL.Inspect do
   @moduledoc false
 
-  @error IO.ANSI.red()
+  @error Application.compile_env(:sql, [:syntax_colors, :error], IO.ANSI.red())
   @reset IO.ANSI.reset()
 
   defimpl Inspect, for: SQL do