Define how CSSMathValue objects serialize. Fixes #489.

w3c · Jan 30, 2018 · 42a9ff0 · 42a9ff0
1 parent 4dc7faf
commit 42a9ff0
Showing 1 changed file with 79 additions and 2 deletions.
diff --git a/css-typed-om/Overview.bs b/css-typed-om/Overview.bs
@@ -2992,9 +2992,86 @@ followed by their {{CSSUnitValue/unit}}.
 {{CSSMathValue}} Serialization {#calc-serialization}
 ---------------------------------------------------------
 
-{{CSSMathValue}} objects are serialized into a ''calc()'' expression
+{{CSSMathValue}} objects are serialized into a [=math function=] as follows:
+
+1. Let |s| initially be the empty [=string=].
+
+2. If the object is a {{CSSMathMin}} or {{CSSMathMax}}:
+    1. Append "min(" or "max(" to |s|, as appropriate.
+
+    2. [=list/For each=] |arg| in the object's {{CSSMathMin/values}} internal slot,
+        serialize |arg| and append the result to |s|,
+        appending a ", " between successive values.
+
+    3. Append ")" to |s|
+        and return |s|.
+
+3. Otherwise, if the object is a {{CSSMathSum}}:
+    1. If this object is nested inside of another {{CSSMathValue}} object,
+        append "(" to |s|;
+        otherwise, append "calc(" to |s|.
+
+    2. Serialize the first [=list/item=] in the object's {{CSSMathSum/values}} internal slot
+        and append the result to |s|.
+
+    3. [=list/For each=] |arg| in the object's {{CSSMathSum/values}} internal slot beyond the first:
+        1. If |arg| is a {{CSSMathNegate}},
+            append " - " to |s|,
+            then serialize |arg|'s {{CSSMathNegate/value}} internal slot
+            and append the result to |s|.
+        2. Otherwise, append " + " to |s|,
+            then serialize |arg|
+            and append the result to |s|.
+
+    4. Append ")" to |s|,
+        and return |s|.
+
+4. Otherwise, if the object is a {{CSSMathNegate}}:
+    1. If this object is nested inside of another {{CSSMathValue}} object,
+        append "(" to |s|;
+        otherwise, append "calc(" to |s|.
+
+    2. Append "-" to |s|.
+
+    3. Serialize the object's {{CSSMathNegate/value}} internal slot
+        and append the result to |s|.
+
+    4. Append ")" to |s|,
+        and return |s|.
+
+5. Otherwise, if the object is a {{CSSMathProduct}}:
+    1. If this object is nested inside of another {{CSSMathValue}} object,
+        append "(" to |s|;
+        otherwise, append "calc(" to |s|.
+
+    2. Serialize the first [=list/item=] in the object's {{CSSMathProduct/values}} internal slot
+        and append the result to |s|.
+
+    3. [=list/For each=] |arg| in the object's {{CSSMathProduct/values}} internal slot beyond the first:
+        1. If |arg| is a {{CSSMathInvert}},
+            append " / " to |s|,
+            then serialize |arg|'s {{CSSMathInvert/value}} internal slot
+            and append the result to |s|.
+        2. Otherwise, append " * " to |s|,
+            then serialize |arg|
+            and append the result to |s|.
+
+    4. Append ")" to |s|,
+        and return |s|.
+
+6. Otherwise, if the object is a {{CSSMathInvert}}:
+    1. If this object is nested inside of another {{CSSMathValue}} object,
+        append "(" to |s|;
+        otherwise, append "calc(" to |s|.
+
+    2. Append "1 / " to |s|.
+
+    3. Serialize the object's {{CSSMathInvert/value}} internal slot
+        and append the result to |s|.
+
+    4. Append ")" to |s|,
+        and return |s|.
 
-Issue(489): TODO
 
 {{CSSTransformValue}} Serialization {#transformvalue-serialization}
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