TokenSet, First(), Follow()

NonTerminals.cs

@@ -0,0 +1,162 @@
+/* M2Sharp -- Modula-2 to C# Translator & Compiler
+ *
+ * Copyright (c) 2016 The Modula-2 Software Foundation
+ *
+ * Author & Maintainer: Benjamin Kowarsch <trijezdci@org.m2sf>
+ *
+ * @synopsis
+ *
+ * M2Sharp is a multi-dialect Modula-2 to C# translator and via-C# compiler.
+ * It supports the dialects described in the 3rd and 4th editions of Niklaus
+ * Wirth's book "Programming in Modula-2" (PIM) published by Springer Verlag,
+ * and an extended mode with select features from the revised language by
+ * B.Kowarsch and R.Sutcliffe "Modula-2 Revision 2010" (M2R10).
+ *
+ * In translator mode, M2Sharp translates Modula-2 source to C# source files.
+ * In compiler mode, M2Sharp compiles Modula-2 source via C# source files
+ * to object code or executables using the host system's C# compiler.
+ *
+ * @repository
+ *
+ * https://github.com/m2sf/m2sharp
+ *
+ * @file
+ *
+ * NonTerminals.cs
+ * 
+ * provides FIRST() and FOLLOW() sets for each non-terminal symbol //SAM CHANGE
+ * used by the parser class for syntax analysis
+ *
+ * @license
+ *
+ * M2Sharp is free software: you can redistribute and/or modify it under the
+ * terms of the GNU Lesser General Public License (LGPL) either version 2.1
+ * or at your choice version 3 as published by the Free Software Foundation.
+ * However, you may not alter the copyright, author and license information.
+ *
+ * M2Sharp is distributed in the hope that it will be useful,  but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  Read the license for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with M2Sharp. If not, see <https://www.gnu.org/copyleft/lesser.html>.
+ *
+ * NB: Components in the domain part of email addresses are in reverse order.
+ */
+
+namespace org.m2sf.m2sharp {
+
+    using System;
+    using System.Collections.Generic;
+
+public class NonTerminals : INonTerminals {
+
+    public static Production firstConstParamDependent = Production.FormalType,
+                             lastConstParamDependent = Production.AttribFormalParams,
+                             firstNoVariantRecDependent = Production.TypeDeclarationTail,
+                             lastNoVariantRecDependent = Production.TypeDeclarationTail,
+                             firstOptionDependent = firstConstParamDependent,
+                             lastOptionDependent = lastNoVariantRecDependent;
+    public static int alternateSetOffset = (int)lastOptionDependent - (int)firstOptionDependent + 1;                         
+
+    /* --------------------------------------------------------------------------
+     * method Count() -- Returns the number of productions
+     * ----------------------------------------------------------------------- */ //SAM CHANGE
+
+    uint Count() {
+        uint total = 0;
+        foreach (String s in Enum.GetNames(typeof(Production))) {
+            total++;
+        }
+        return total;
+    } /* end Count */
+
+
+    /* --------------------------------------------------------------------------
+     * method IsOptionDependent(p)
+     * --------------------------------------------------------------------------
+     * Returns true if p is dependent on any compiler option, else false.
+     * ----------------------------------------------------------------------- */ //SAM CHANGE
+
+    bool IsOptionDependent(Production p) {
+        return p >= firstOptionDependent;
+    } /* end IsOptionDependent */
+
+
+    /* --------------------------------------------------------------------------
+     * method IsConstParamDependent(p)
+     * --------------------------------------------------------------------------
+     * Returns true if p is dependent on CONST parameter option, else false.
+     * ----------------------------------------------------------------------- */ //SAM CHANGE
+
+    bool IsConstParamDependent(Production p)
+    {
+        return p >= firstConstParamDependent && p <= lastConstParamDependent;
+    } /* end IsConstParamDependent */
+
+
+    /* --------------------------------------------------------------------------
+     * method IsVariantRecordDependent(p)
+     * --------------------------------------------------------------------------
+     * Returns true if p is dependent on variant record type option, else false.
+     * ----------------------------------------------------------------------- */ //SAM CHANGE
+
+    bool IsVariantRecordDependent(Production p) {
+        return p >= firstNoVariantRecDependent && p <= lastNoVariantRecDependent;
+    }
+
+    /* --------------------------------------------------------------------------
+     * method FIRST(p)
+     * --------------------------------------------------------------------------
+     * Returns a tokenset with the FIRST set of production p.
+     * ----------------------------------------------------------------------- */
+
+    TokenSet FIRST(Production p) {
+        TokenSet tokenset = null;
+
+        if (IsConstParamDependent(p))
+        {
+            p += alternateSetOffset;
+        } /* end if */
+        if (IsVariantRecordDependent(p) && CompilerOptions.VariantRecords())
+        {
+            p += alternateSetOffset;
+        } /* end if */
+
+        return tokenset;
+    } /* end FIRST */
+
+
+    /* --------------------------------------------------------------------------
+     * method FOLLOW(p)
+     * --------------------------------------------------------------------------
+     * Returns a tokenset with the FOLLOW set of production p.
+     * ----------------------------------------------------------------------- */
+
+    TokenSet FOLLOW(Production p) {
+        TokenSet tokenset = null;
+
+        if (IsConstParamDependent(p)) {
+            p += alternateSetOffset;
+        } /* end if */
+        if (IsVariantRecordDependent(p) && !CompilerOptions.VariantRecords()) {
+            p += alternateSetOffset;
+        } /* end if */
+
+        return tokenset;
+    } /* end FOLLOW */
+
+
+    /* --------------------------------------------------------------------------
+     * method NameForProduction(p)
+     * --------------------------------------------------------------------------
+     * Returns a string with a human readable name for production p.
+     * ----------------------------------------------------------------------- */
+
+    string NameForProduction(Production p);
+
+
+
+} /* NonTerminals */
+
+} /* namespace */