Fix #420 - Expression with trailing space (#421)

sys27 · Apr 29, 2021 · f85d478 · f85d478
1 parent 3e23165
commit f85d478
Show file tree

Hide file tree

Showing 6 changed files with 28 additions and 42 deletions.
diff --git a/.vscode/launch.json b/.vscode/launch.json
@@ -6,7 +6,7 @@
             "type": "coreclr",
             "request": "launch",
             "preLaunchTask": "Build",
-            "program": "${workspaceFolder}/xFunc.Benchmark/bin/Debug/netcoreapp3.1/xFunc.Benchmark.dll",
+            "program": "${workspaceFolder}/xFunc.Benchmark/bin/Debug/net5.0/xFunc.Benchmark.dll",
             "args": [],
             "cwd": "${workspaceFolder}/xFunc.Benchmark",
             "console": "internalConsole",
@@ -17,7 +17,7 @@
             "type": "coreclr",
             "request": "launch",
             "preLaunchTask": "Build",
-            "program": "${workspaceFolder}/xFunc.DotnetTool/bin/Debug/netcoreapp3.0/xFunc.DotnetTool.dll",
+            "program": "${workspaceFolder}/xFunc.DotnetTool/bin/Debug/net5.0/xFunc.DotnetTool.dll",
             "args": [
                 "interactive"
             ],

diff --git a/xFunc.Maths/Parser.TokenReader.cs b/xFunc.Maths/Parser.TokenReader.cs
@@ -76,8 +76,8 @@ private void EnsureEnoughSpace()
                 // read from enumerator and write to buffer
                 if (readIndex == writeIndex)
                 {
-                    var result = lexer.MoveNext();
-                    if (!result)
+                    var hasNextItem = lexer.MoveNext();
+                    if (!hasNextItem)
                         IsEnd = true;
 
                     if (scopeCount == 0)

diff --git a/xFunc.Maths/Parser.cs b/xFunc.Maths/Parser.cs
@@ -642,7 +642,7 @@ public IExpression Parse(string expression)
             });
 
         private IExpression? ParseOperand(ref TokenReader tokenReader)
-            => ParseComplexNumber(ref tokenReader) ??
+            => ParsePolarComplexNumber(ref tokenReader) ??
                ParseNumber(ref tokenReader) ??
                ParseIf(ref tokenReader) ??
                ParseFunctionOrVariable(ref tokenReader) ??
@@ -755,7 +755,7 @@ private ImmutableArray<IExpression> ParseParameterList(ref TokenReader tokenRead
             return new Number(number.NumberValue);
         }
 
-        private IExpression? ParseComplexNumber(ref TokenReader tokenReader)
+        private IExpression? ParsePolarComplexNumber(ref TokenReader tokenReader)
             => tokenReader.Scoped(this, static (Parser parser, ref TokenReader reader) =>
             {
                 // plus symbol can be ignored

diff --git a/xFunc.Maths/Tokenization/Lexer.WhiteSpace.cs b/xFunc.Maths/Tokenization/Lexer.WhiteSpace.cs
diff --git a/xFunc.Maths/Tokenization/Lexer.cs b/xFunc.Maths/Tokenization/Lexer.cs
@@ -49,10 +49,8 @@ public Lexer(string function)
         /// </returns>
         public bool MoveNext()
         {
-            while (function.Length > 0)
+            while (HasSymbols())
             {
-                SkipWhiteSpaces();
-
                 var result = CreateNumberToken() ||
                              CreateIdToken() ||
                              CreateOperatorToken() ||
@@ -68,6 +66,18 @@ public bool MoveNext()
             return false;
         }
 
+        private bool HasSymbols()
+        {
+            var index = 0;
+            while (index < function.Length && char.IsWhiteSpace(function[index]))
+                index++;
+
+            if (index > 0)
+                function = function[index..];
+
+            return function.Length > 0;
+        }
+
         /// <summary>
         /// Gets the element in the collection at the current position of the enumerator.
         /// </summary>

diff --git a/xFunc.Tests/ParserTests/ParserTest.cs b/xFunc.Tests/ParserTests/ParserTest.cs
@@ -705,5 +705,14 @@ public void ToOctTest()
         [Fact]
         public void ToHexTest()
             => ParseTest("tohex(10)", new ToHex(new Number(10)));
+
+        [Fact]
+        public void LeadingSpaces()
+            => ParseTest("  1", Number.One);
+
+        [Fact]
+        public void TrailingSpaces()
+            => ParseTest("1  ", Number.One);
+
     }
 }