#14: ignore empty delimiters instead of defining them as null

ForNeVeR · Feb 26, 2017 · 9dd8ce4 · 9dd8ce4
1 parent c2ef630
commit 9dd8ce4
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Showing 5 changed files with 14 additions and 32 deletions.
diff --git a/src/WpfMath.Tests/ParserTests.fs b/src/WpfMath.Tests/ParserTests.fs
@@ -43,9 +43,10 @@ type ParserTests() =
     [<Theory>]
     [<InlineData(".", ")", true, false)>]
     [<InlineData("(", ".", false, true)>]
-    let ``Empty delimiters should work`` (left : string, right : string, isLeftNull : bool, isRightNull : bool) =
-        let leftBrace = if isLeftNull then null else (openBrace "lbrack")
-        let rightBrace = if isRightNull then null else (closeBrace "rbrack")
+    let ``Empty delimiters should work`` (left : string, right : string, isLeftEmpty : bool, isRightEmpty : bool) =
+        let empty = brace SymbolAtom.EmptyDelimiterName TexAtomType.Ordinary
+        let leftBrace = if isLeftEmpty then empty else (openBrace "lbrack")
+        let rightBrace = if isRightEmpty then empty else (closeBrace "rbrack")
 
         assertParseResult
         <| sprintf @"\left%sa\right%s" left right
@@ -55,7 +56,7 @@ type ParserTests() =
     let ``Unmatched delimiters should work`` () =
         assertParseResult
         <| @"\left)a\right|"
-        <| (formula <| fenced (closeBrace "rbrack") (char 'a') (SymbolAtom("vert", TexAtomType.Ordinary, true)))
+        <| (formula <| fenced (closeBrace "rbrack") (char 'a') (brace "vert" TexAtomType.Ordinary))
 
     [<Fact>]
     let ``Expression in braces should be parsed`` () =

diff --git a/src/WpfMath.Tests/Utils.fs b/src/WpfMath.Tests/Utils.fs
@@ -8,7 +8,7 @@ let formula (root : Atom) : TexFormula =
 let char (c : char) : CharAtom = CharAtom(c)
 let styledChar (c : char, style:string) : CharAtom = CharAtom(c, style)
 let op (baseAtom : Atom) (useVertScripts : System.Nullable<bool>)  : BigOperatorAtom = BigOperatorAtom(baseAtom, null, null, useVertScripts)
-let opWithScripts (baseAtom : Atom) (subscript : Atom) (superscript : Atom) (useVertScripts : System.Nullable<bool>) 
+let opWithScripts (baseAtom : Atom) (subscript : Atom) (superscript : Atom) (useVertScripts : System.Nullable<bool>)
             : BigOperatorAtom = BigOperatorAtom(baseAtom, subscript, superscript, useVertScripts)
 let group (groupedAtom: Atom) : TypedAtom = TypedAtom(groupedAtom, TexAtomType.Ordinary, TexAtomType.Ordinary)
 let symbol (name : string) : SymbolAtom = SymbolAtom(name, TexAtomType.BinaryOperator, false)
@@ -19,5 +19,6 @@ let row (children : Atom seq) : RowAtom =
     result
 let fenced left body right : FencedAtom = FencedAtom(body, left, right)
 
-let openBrace (name : string) : SymbolAtom = SymbolAtom(name, TexAtomType.Opening, true)
-let closeBrace (name : string) : SymbolAtom = SymbolAtom(name, TexAtomType.Closing, true)
+let brace (name : string) (braceType : TexAtomType) : SymbolAtom = SymbolAtom(name, braceType, true)
+let openBrace (name : string) : SymbolAtom = brace name TexAtomType.Opening
+let closeBrace (name : string) : SymbolAtom = brace name TexAtomType.Closing
diff --git a/src/WpfMath/FencedAtom.cs b/src/WpfMath/FencedAtom.cs
@@ -1,7 +1,4 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
 
 namespace WpfMath
 {
@@ -57,7 +54,7 @@ public override Box CreateBox(TexEnvironment environment)
             var minHeight = Math.Max((delta / 500) * delimeterFactor, 2 * delta - delimeterShortfall);
 
             // Create and add box for left delimeter.
-            if (LeftDelimeter != null)
+            if (LeftDelimeter != null && LeftDelimeter.Name != SymbolAtom.EmptyDelimiterName)
             {
                 var leftDelimeterBox = DelimiterFactory.CreateBox(this.LeftDelimeter.Name, minHeight, environment);
                 CentreBox(leftDelimeterBox, axis);
@@ -76,7 +73,7 @@ public override Box CreateBox(TexEnvironment environment)
                 resultBox.Add(Glue.CreateBox(this.BaseAtom.GetRightType(), TexAtomType.Closing, environment));
 
             // Create and add box for right delimeter.
-            if (this.RightDelimeter != null)
+            if (RightDelimeter != null && RightDelimeter.Name != SymbolAtom.EmptyDelimiterName)
             {
                 var rightDelimeterBox = DelimiterFactory.CreateBox(this.RightDelimeter.Name, minHeight, environment);
                 CentreBox(rightDelimeterBox, axis);

diff --git a/src/WpfMath/TexFormulaHelper.cs b/src/WpfMath/TexFormulaHelper.cs
@@ -64,11 +64,8 @@ public void AddEmbraced(string formula, string leftSymbol, string rightSymbol)
 
         public void AddEmbraced(TexFormula formula, string leftSymbol, string rightSymbol)
         {
-            Add(
-                PrepareFencedAtom(
-                    formula?.RootAtom,
-                    TexFormulaParser.GetDelimiterSymbol(leftSymbol),
-                    TexFormulaParser.GetDelimiterSymbol(rightSymbol)));
+            Add(new FencedAtom(formula == null ? null : formula.RootAtom, TexFormulaParser.GetDelimiterSymbol(leftSymbol),
+                TexFormulaParser.GetDelimiterSymbol(rightSymbol)));
         }
 
         public void AddFraction(string numerator, string denominator, bool drawLine)
@@ -307,19 +304,5 @@ public void PutUnderAndOver(TexFormula underFormula, TexUnit underUnit, double u
                 null : underFormula.RootAtom, underUnit, underSpace, underScriptSize, over == null ? null : over.RootAtom,
                 overUnit, overSpace, overScriptSize);
         }
-
-        internal static FencedAtom PrepareFencedAtom(
-            Atom baseAtom,
-            SymbolAtom leftDelimiter,
-            SymbolAtom rightDelimiter)
-        {
-            if (leftDelimiter.Name == SymbolAtom.EmptyDelimiterName)
-                leftDelimiter = null;
-
-            if (rightDelimiter.Name == SymbolAtom.EmptyDelimiterName)
-                rightDelimiter = null;
-
-            return new FencedAtom(baseAtom, leftDelimiter, rightDelimiter);
-        }
     }
 }
diff --git a/src/WpfMath/TexFormulaParser.cs b/src/WpfMath/TexFormulaParser.cs
@@ -317,7 +317,7 @@ private Atom ProcessCommand(
                             throw new TexParseException($"Cannot find delimiter named {delimiter}");
 
                         var closing = internals.ClosingDelimiter;
-                        return TexFormulaHelper.PrepareFencedAtom(internals.Body, opening, closing);
+                        return new FencedAtom(internals.Body, opening, closing);
                     }
 
                 case "right":