test

My project/Library/PackageCache/com.unity.inputsystem/InputSystem/Utilities/PredictiveParser.cs

@@ -0,0 +1,148 @@
+using System;
+
+namespace UnityEngine.InputSystem.Utilities
+{
+    // this parser uses Span<T> so it's only available from later unity versions
+#if UNITY_2021_2_OR_NEWER
+    internal struct PredictiveParser
+    {
+        public void ExpectSingleChar(ReadOnlySpan<char> str, char c)
+        {
+            if (str[m_Position] != c)
+                throw new InvalidOperationException($"Expected a '{c}' character at position {m_Position} in : {str.ToString()}");
+
+            ++m_Position;
+        }
+
+        public int ExpectInt(ReadOnlySpan<char> str)
+        {
+            int pos = m_Position;
+
+            int sign = 1;
+            if (str[pos] == '-')
+            {
+                sign = -1;
+                ++pos;
+            }
+
+            int value = 0;
+            for (;;)
+            {
+                var n = str[pos];
+                if (n >= '0' && n <= '9')
+                {
+                    value *= 10;
+                    value += n - '0';
+                    ++pos;
+                }
+                else
+                    break;
+            }
+
+            if (m_Position == pos)
+                throw new InvalidOperationException($"Expected an int at position {m_Position} in {str.ToString()}");
+
+            m_Position = pos;
+            return value * sign;
+        }
+
+        public ReadOnlySpan<char> ExpectString(ReadOnlySpan<char> str)
+        {
+            var startPos = m_Position;
+            if (str[startPos] != '\"')
+                throw new InvalidOperationException($"Expected a '\"' character at position {m_Position} in {str.ToString()}");
+
+            ++m_Position;
+
+            for (;;)
+            {
+                var c = str[m_Position];
+                c |= ' ';
+                if (c >= 'a' && c <= 'z')
+                {
+                    ++m_Position;
+                    continue;
+                }
+
+                break;
+            }
+
+            // if the first non-alpha character is not a quote, throw
+            if (str[m_Position] != '\"')
+                throw new InvalidOperationException($"Expected a closing '\"' character at position {m_Position} in string: {str.ToString()}");
+
+            if (m_Position - startPos == 1)
+                return ReadOnlySpan<char>.Empty;
+
+            var output = str.Slice(startPos + 1, m_Position - startPos - 1);
+
+            ++m_Position;
+            return output;
+        }
+
+        public bool AcceptSingleChar(ReadOnlySpan<char> str, char c)
+        {
+            if (str[m_Position] != c)
+                return false;
+
+            m_Position++;
+            return true;
+        }
+
+        public bool AcceptString(ReadOnlySpan<char> input, out ReadOnlySpan<char> output)
+        {
+            output = default;
+            var startPos = m_Position;
+            var endPos = startPos;
+            if (input[endPos] != '\"')
+                return false;
+
+            ++endPos;
+
+            for (;;)
+            {
+                var c = input[endPos];
+                c |= ' ';
+                if (c >= 'a' && c <= 'z')
+                {
+                    ++endPos;
+                    continue;
+                }
+
+                break;
+            }
+
+            // if the first non-alpha character is not a quote, throw
+            if (input[endPos] != '\"')
+                return false;
+
+            // empty string?
+            if (m_Position - startPos == 1)
+                output = ReadOnlySpan<char>.Empty;
+            else
+                output = input.Slice(startPos + 1, endPos - startPos - 1);
+
+            m_Position = endPos + 1;
+            return true;
+        }
+
+        public void AcceptInt(ReadOnlySpan<char> str)
+        {
+            // skip negative sign
+            if (str[m_Position] == '-')
+                ++m_Position;
+
+            for (;;)
+            {
+                var n = str[m_Position];
+                if (n >= '0' && n <= '9')
+                    ++m_Position;
+                else
+                    break;
+            }
+        }
+
+        private int m_Position;
+    }
+#endif
+}