add wezterm.color.save_scheme for exporting color schemes

config/src/color.rs

@@ -1,6 +1,6 @@
 use crate::*;
 use luahelper::impl_lua_conversion_dynamic;
-use std::convert::TryFrom;
+use std::convert::{TryFrom, TryInto};
 use std::str::FromStr;
 use termwiz::cell::CellAttributes;
 pub use termwiz::color::{ColorSpec, RgbColor, SrgbaTuple};
@@ -451,6 +451,39 @@ pub struct ColorSchemeFile {
 }
 impl_lua_conversion_dynamic!(ColorSchemeFile);
 
+fn dynamic_to_toml(value: Value) -> anyhow::Result<toml::Value> {
+    Ok(match value {
+        Value::Null => anyhow::bail!("cannot map Null to toml"),
+        Value::Bool(b) => toml::Value::Boolean(b),
+        Value::String(s) => toml::Value::String(s),
+        Value::Array(a) => {
+            let mut arr = vec![];
+            for v in a {
+                arr.push(dynamic_to_toml(v)?);
+            }
+            toml::Value::Array(arr)
+        }
+        Value::Object(o) => {
+            let mut map = toml::value::Map::new();
+            for (k, v) in o {
+                let k = match k {
+                    Value::String(s) => s,
+                    _ => anyhow::bail!("toml keys must be strings {k:?}"),
+                };
+                let v = match v {
+                    Value::Null => continue,
+                    other => dynamic_to_toml(other)?,
+                };
+                map.insert(k, v);
+            }
+            toml::Value::Table(map)
+        }
+        Value::U64(i) => toml::Value::Integer(i.try_into()?),
+        Value::I64(i) => toml::Value::Integer(i.try_into()?),
+        Value::F64(f) => toml::Value::Float(*f),
+    })
+}
+
 impl ColorSchemeFile {
     pub fn from_toml_value(value: &toml::Value) -> anyhow::Result<Self> {
         Self::from_dynamic(&crate::toml_to_dynamic(value), Default::default())
@@ -472,6 +505,18 @@ impl ColorSchemeFile {
         }
         Ok(scheme)
     }
+
+    pub fn to_toml_value(&self) -> anyhow::Result<toml::Value> {
+        let value = self.to_dynamic();
+        Ok(dynamic_to_toml(value)?)
+    }
+
+    pub fn save_to_file<P: AsRef<Path>>(&self, path: P) -> anyhow::Result<()> {
+        let value = self.to_toml_value()?;
+        let text = toml::to_string_pretty(&value)?;
+        std::fs::write(&path, text)
+            .with_context(|| format!("writing toml to {}", path.as_ref().display()))
+    }
 }
 
 #[cfg(test)]

docs/config/lua/wezterm.color/save_scheme.md

@@ -0,0 +1,82 @@
+# `wezterm.color.save_scheme(colors, metadata, file_name)`
+
+*Since: nightly builds only*
+
+Saves a color scheme as a wezterm TOML file.
+This is useful when sharing your custom color scheme with others.
+While you could share the lua representation of the scheme, the
+TOML file is recommended for sharing as it is purely declarative:
+no executable logic is present in the TOML color scheme which makes
+it safe to consume "random" schemes from the internet.
+
+This example demonstrates importing a base16 scheme and exporting
+it as a wezterm scheme.
+
+Given a yaml file with these contents:
+
+```yaml
+scheme: "Cupcake"
+author: "Chris Kempson (http://chriskempson.com)"
+base00: "fbf1f2"
+base01: "f2f1f4"
+base02: "d8d5dd"
+base03: "bfb9c6"
+base04: "a59daf"
+base05: "8b8198"
+base06: "72677E"
+base07: "585062"
+base08: "D57E85"
+base09: "EBB790"
+base0A: "DCB16C"
+base0B: "A3B367"
+base0C: "69A9A7"
+base0D: "7297B9"
+base0E: "BB99B4"
+base0F: "BAA58C"
+```
+
+Then:
+
+```lua
+> colors, metadata = wezterm.color.load_base16_scheme("/tmp/cupcake.yaml")
+> wezterm.color.save_scheme(colors, metadata, "/tmp/cupcacke.toml")
+```
+
+produces a toml file with these contents:
+
+```toml
+[colors]
+ansi = [
+    '#fbf1f2',
+    '#d57e85',
+    '#a3b367',
+    '#dcb16c',
+    '#7297b9',
+    '#bb99b4',
+    '#69a9a7',
+    '#8b8198',
+]
+background = '#fbf1f2'
+brights = [
+    '#bfb9c6',
+    '#d57e85',
+    '#a3b367',
+    '#dcb16c',
+    '#7297b9',
+    '#bb99b4',
+    '#69a9a7',
+    '#585062',
+]
+cursor_bg = '#8b8198'
+cursor_border = '#8b8198'
+cursor_fg = '#8b8198'
+foreground = '#8b8198'
+selection_bg = '#8b8198'
+selection_fg = '#fbf1f2'
+
+[colors.indexed]
+
+[metadata]
+author = 'Chris Kempson (http://chriskempson.com)'
+name = 'Cupcake'
+```

lua-api-crates/color-funcs/src/lib.rs

@@ -2,7 +2,7 @@ use crate::schemes::base16::Base16Scheme;
 use crate::schemes::sexy::Sexy;
 use config::lua::mlua::{self, Lua, MetaMethod, UserData, UserDataMethods};
 use config::lua::{get_or_create_module, get_or_create_sub_module};
-use config::{ColorSchemeFile, Gradient, Palette, RgbaColor, SrgbaTuple};
+use config::{ColorSchemeFile, ColorSchemeMetaData, Gradient, Palette, RgbaColor, SrgbaTuple};
 
 mod image_colors;
 pub mod schemes;
@@ -135,6 +135,19 @@ pub fn register(lua: &Lua) -> anyhow::Result<()> {
             Ok((scheme.colors, scheme.metadata))
         })?,
     )?;
+
+    color.set(
+        "save_scheme",
+        lua.create_function(
+            |_, (colors, metadata, file_name): (Palette, ColorSchemeMetaData, String)| {
+                let scheme = ColorSchemeFile { colors, metadata };
+                scheme
+                    .save_to_file(file_name)
+                    .map_err(|err| mlua::Error::external(format!("{err:#}")))
+            },
+        )?,
+    )?;
+
     color.set(
         "load_terminal_sexy_scheme",
         lua.create_function(|_, file_name: String| {

sync-color-schemes/src/main.rs

@@ -6,7 +6,6 @@ use sqlite_cache::Cache;
 use std::collections::BTreeMap;
 use std::path::Path;
 use std::time::Duration;
-use wezterm_dynamic::{ToDynamic, Value};
 
 mod base16;
 mod gogh;

sync-color-schemes/src/scheme.rs

@@ -9,8 +9,7 @@ pub struct Scheme {
 
 impl Scheme {
     pub fn to_toml_value(&self) -> anyhow::Result<toml::Value> {
-        let value = self.data.to_dynamic();
-        Ok(dynamic_to_toml(value)?)
+        self.data.to_toml_value()
     }
 
     pub fn to_toml(&self) -> anyhow::Result<String> {
@@ -45,36 +44,3 @@ impl Scheme {
         Ok(serde_json::from_str(&json)?)
     }
 }
-
-fn dynamic_to_toml(value: Value) -> anyhow::Result<toml::Value> {
-    Ok(match value {
-        Value::Null => anyhow::bail!("cannot map Null to toml"),
-        Value::Bool(b) => toml::Value::Boolean(b),
-        Value::String(s) => toml::Value::String(s),
-        Value::Array(a) => {
-            let mut arr = vec![];
-            for v in a {
-                arr.push(dynamic_to_toml(v)?);
-            }
-            toml::Value::Array(arr)
-        }
-        Value::Object(o) => {
-            let mut map = toml::value::Map::new();
-            for (k, v) in o {
-                let k = match k {
-                    Value::String(s) => s,
-                    _ => anyhow::bail!("toml keys must be strings {k:?}"),
-                };
-                let v = match v {
-                    Value::Null => continue,
-                    other => dynamic_to_toml(other)?,
-                };
-                map.insert(k, v);
-            }
-            toml::Value::Table(map)
-        }
-        Value::U64(i) => toml::Value::Integer(i.try_into()?),
-        Value::I64(i) => toml::Value::Integer(i.try_into()?),
-        Value::F64(f) => toml::Value::Float(*f),
-    })
-}