Precision can be controlled per channel (#438)

* Precision can be controlled per channel

This reverts the precision_alpha change made in a previous commit for a
more flexible approach.

* Fix lint

coloraide/color.py

@@ -186,7 +186,7 @@ def __init__(
     def __len__(self) -> int:
         """Get number of channels."""
 
-        return len(self._space.CHANNELS) + 1
+        return len(self._space.channels)
 
     @overload
     def __getitem__(self, i: str | int) -> float:
@@ -531,14 +531,14 @@ def to_dict(
         self,
         *,
         nans: bool = True,
-        precision: int | None = None,
-        precision_alpha: int | None = None
+        precision: int | Sequence[int] | None = None
     ) -> Mapping[str, Any]:
         """Return color as a data object."""
 
-        # Assume precision of other coordinates for alpha if only precision is specified
-        if precision is not None and precision_alpha is None:
+        if precision is None or isinstance(precision, int):
             precision_alpha = precision
+        else:
+            precision_alpha = util.get_index(precision, len(self._space.channels) - 1, self.PRECISION)
 
         return {
             'space': self.space(),
@@ -1293,58 +1293,72 @@ def contrast(self, color: ColorInput, method: str | None = None) -> float:
         return contrast.contrast(method, self, color)
 
     @overload
-    def get(self, name: str, *, nans: bool = True, precision: int | None = None) -> float:
+    def get(self,
+        name: str,
+        *,
+        nans: bool = True,
+        precision: int | Sequence[int] | None = None
+    ) -> float:
         ...
 
     @overload
-    def get(self, name: list[str] | tuple[str, ...], *, nans: bool = True, precision: int | None = None) -> Vector:
+    def get(
+        self,
+        name: list[str] | tuple[str, ...],
+        *,
+        nans: bool = True,
+        precision: int | Sequence[int] | None = None
+    ) -> Vector:
         ...
 
     def get(
         self, name: str | list[str] | tuple[str, ...],
         *,
         nans: bool = True,
-        precision: int | None = None
+        precision: int | Sequence[int] | None = None
     ) -> float | Vector:
         """Get channel."""
 
+        is_plist = precision is not None and not isinstance(precision, int)
+
         # Handle single channel
         if isinstance(name, str):
             # Handle space.channel
             if '.' in name:
                 space, channel = name.split('.', 1)
+                obj = self.convert(space, norm=nans)
                 if nans:
-                    v = self.convert(space)[channel]
+                    v = obj[channel]
                 else:
-                    obj = self.convert(space, norm=nans)
                     i = obj._space.get_channel_index(channel)
                     v = obj._space.resolve_channel(i, obj._coords)
             elif nans:
                 v = self[name]
             else:
                 i = self._space.get_channel_index(name)
-                v = self._space.resolve_channel(i, self._coords)
-            return v if precision is None else alg.round_to(v, precision)
+                v = self._space.resolve_channel(self._space.get_channel_index(name), self._coords)
+            return v if precision is None else alg.round_to(v, util.get_index(precision, 0) if is_plist else precision)  # type: ignore[arg-type]
 
         # Handle list of channels
         else:
             original_space = current_space = self.space()
             obj = self
             values = []
 
-            for n in name:
+            for e, n in enumerate(name):
                 # Handle space.channel
                 space, channel = n.split('.', 1) if '.' in n else (original_space, n)
                 if space != current_space:
                     obj = self if space == original_space else self.convert(space, norm=nans)
                     current_space = space
                 if nans:
                     v = obj[channel]
-                    values.append(v if precision is None else alg.round_to(v, precision))
                 else:
                     i = obj._space.get_channel_index(channel)
                     v = obj._space.resolve_channel(i, obj._coords)
-                    values.append(v if precision is None else alg.round_to(v, precision))
+                values.append(
+                    v if precision is None else alg.round_to(v, util.get_index(precision, e) if is_plist else precision)  # type: ignore[arg-type]
+                )
             return values
 
     def set(  # noqa: A003
@@ -1406,22 +1420,38 @@ def set(  # noqa: A003
 
         return self
 
-    def coords(self, *, nans: bool = True, precision: int | None = None) -> Vector:
+    def coords(self, *, nans: bool = True, precision: int | Sequence[int] | None = None) -> Vector:
         """Get the color channels and optionally remove undefined values."""
 
-        if nans:
-            value = self[:-1]
+        # Full precision
+        if precision is None:
+            if nans:
+                return self[:-1]
+            else:
+                return [
+                    self._space.resolve_channel(index, self._coords)
+                    for index in range(len(self._coords) - 1)
+                ]
+        # Specific precision requested
+        elif isinstance(precision, int):
+            return [
+                alg.round_to(self[index] if nans else self._space.resolve_channel(index, self._coords), precision)
+                for index in range(len(self._coords) - 1)
+            ]
+        # Channel specific list of precision
         else:
-            value = [self._space.resolve_channel(index, self._coords) for index in range(len(self._coords) - 1)]
-        return value if precision is None else [alg.round_to(v, precision) for v in value]
+            return [
+                alg.round_to(
+                    self[index] if nans else self._space.resolve_channel(index, self._coords),
+                    util.get_index(precision, index, self.PRECISION)
+                )
+                for index in range(len(self._coords) - 1)
+            ]
 
     def alpha(self, *, nans: bool = True, precision: int | None = None) -> float:
         """Get the alpha channel."""
 
-        if nans:
-            value = self[-1]
-        else:
-            value = self._space.resolve_channel(-1, self._coords)
+        value = self[-1] if nans else self._space.resolve_channel(-1, self._coords)
         return value if precision is None else alg.round_to(value, precision)
 
 

coloraide/css/serialize.py

@@ -37,8 +37,7 @@ def color_function(
     obj: Color,
     func: str | None,
     alpha: bool | None,
-    precision: int,
-    precision_alpha: int,
+    precision: int | Sequence[int],
     fit: str | bool | dict[str, Any],
     none: bool,
     percent: bool | Sequence[bool],
@@ -70,10 +69,10 @@ def color_function(
     # - A list of booleans will attempt formatting the associated channel as percent,
     #   anything not specified is assumed `False`.
     if isinstance(percent, bool):
-        plist = obj._space._percents if percent else []
-    else:
-        diff = l - len(percent)
-        plist = list(percent) + ([False] * diff) if diff > 0 else list(percent)
+        percent = obj._space._percents if percent else []
+
+    # Ensure precision list is filled
+    is_precision_list = not isinstance(precision, int)
 
     # Iterate the coordinates formatting them by scaling the values, formatting for percent, etc.
     for idx, value in enumerate(coords):
@@ -84,7 +83,7 @@ def color_function(
             string.append(COMMA if legacy else SPACE)
         channel = channels[idx]
 
-        if not (channel.flags & FLG_ANGLE) and plist and plist[idx]:
+        if not (channel.flags & FLG_ANGLE) and percent and util.get_index(percent, idx, False):
             span, offset = channel.span, channel.offset
         else:
             span = offset = 0.0
@@ -94,7 +93,7 @@ def color_function(
         string.append(
             util.fmt_float(
                 value,
-                precision_alpha if is_last else precision,
+                util.get_index(precision, idx, obj.PRECISION) if is_precision_list else precision,  # type: ignore[arg-type]
                 span,
                 offset
             )
@@ -178,8 +177,7 @@ def serialize_css(
     func: str = '',
     color: bool = False,
     alpha: bool | None = None,
-    precision: int | None = None,
-    precision_alpha: int | None = None,
+    precision: int | Sequence[int] | None = None,
     fit: bool | str | dict[str, Any] = True,
     none: bool = False,
     percent: bool | Sequence[bool] = False,
@@ -195,12 +193,9 @@ def serialize_css(
     if precision is None:
         precision = obj.PRECISION
 
-    if precision_alpha is None:
-        precision_alpha = precision
-
     # Color format
     if color:
-        return color_function(obj, None, alpha, precision, precision_alpha, fit, none, percent, False, 1.0)
+        return color_function(obj, None, alpha, precision, fit, none, percent, False, 1.0)
 
     # CSS color names
     if name:
@@ -214,6 +209,6 @@ def serialize_css(
 
     # Normal CSS named function format
     if func:
-        return color_function(obj, func, alpha, precision, precision_alpha, fit, none, percent, legacy, scale)
+        return color_function(obj, func, alpha, precision, fit, none, percent, legacy, scale)
 
     raise RuntimeError('Could not identify a CSS format to serialize to')  # pragma: no cover

coloraide/spaces/__init__.py

@@ -258,8 +258,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: str | bool | dict[str, Any] = True,
         none: bool = False,
         percent: bool | Sequence[bool] = False,
@@ -272,7 +271,6 @@ def to_string(
             color=True,
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             percent=percent

coloraide/spaces/hsl/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -45,7 +44,6 @@ def to_string(
             func='hsl',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/hwb/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -36,7 +35,6 @@ def to_string(
             func='hwb',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/lab/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -33,7 +32,6 @@ def to_string(
             func='lab',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/lch/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -33,7 +32,6 @@ def to_string(
             func='lch',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/oklab/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -33,7 +32,6 @@ def to_string(
             func='oklab',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/oklch/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -33,7 +32,6 @@ def to_string(
             func='oklch',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,

coloraide/spaces/srgb/css.py

@@ -18,8 +18,7 @@ def to_string(
         parent: Color,
         *,
         alpha: bool | None = None,
-        precision: int | None = None,
-        precision_alpha: int | None = None,
+        precision: int | Sequence[int] | None = None,
         fit: bool | str | dict[str, Any] = True,
         none: bool = False,
         color: bool = False,
@@ -38,7 +37,6 @@ def to_string(
             func='rgb',
             alpha=alpha,
             precision=precision,
-            precision_alpha=precision_alpha,
             fit=fit,
             none=none,
             color=color,