Centralizes the processing of (read) expressions.

1 files changed, 107 insertions, 0 deletions

diff --git a/ast-to-instr/src/Expressions.java b/ast-to-instr/src/Expressions.java
new file mode 100644
index 0000000..a4c4bbf
--- /dev/null
+++ b/ast-to-instr/src/Expressions.java
@@ -0,0 +1,107 @@
+import java.util.Map;
+import java.util.HashMap;
+
+import javax.xml.xpath.XPathExpression;
+import javax.xml.xpath.XPathExpressionException;
+
+public class Expressions
+{
+   private static final XPathExpression XPE_GET_LEFT, XPE_GET_RIGHT;
+
+   static
+   {
+      XPE_GET_LEFT = XMLManager.compile_or_die("./left");
+      XPE_GET_RIGHT = XMLManager.compile_or_die("./right");
+   }
+
+   private static enum Operator
+   {
+      /* From GHDL's ./src/vhdl/nodes_meta.adb */
+      IDENTITY("identity_operator", false), /* assuming it means "+ number" */
+      NEGATION("negation_operator", false), /* assuming it means "- number" */
+      ABSOLUTE("absolute_operator", false),
+
+      NOT("not_operator", false),
+
+      CONDITION("condition_operator", true), /* FIXME: what's this? */
+
+      /* Flattens vectors using an operator. */
+      REDUCTION_AND("reduction_and_operator", false),
+      REDUCTION_OR("reduction_or_operator", false),
+      REDUCTION_NAND("reduction_nand_operator", false),
+      REDUCTION_NOR("reduction_nor_operator", false),
+      REDUCTION_XOR("reduction_xor_operator", false),
+      REDUCTION_XNOR("reduction_xnor_operator", false),
+
+      AND("and_operator", true),
+      OR("or_operator", true),
+      NAND("nand_operator", true),
+      NOR("nor_operator", true),
+      XOR("xor_operator", true),
+      XNOR("xnor_operator", true),
+
+      EQUALITY("equality_operator", true),
+      INEQUALITY("inequality_operator", true),
+      LESS_THAN("less_than_operator", true),
+      LESS_THAN_OR_EQUAL("less_than_or_equal_operator", true),
+      GREATER_THAN("greater_than_operator", true),
+      GREATER_THAN_OR_EQUAL("greater_than_or_equal_operator", true),
+
+      /* FIXME: What are those? */
+      MATCH_EQUALITY("match_equality_operator", true),
+      MATCH_INEQUALITY("match_inequality_operator", true),
+      MATCH_LESS_THAN("match_less_than_operator", true),
+      MATCH_LESS_THAN_OR_EQUAL("match_less_than_or_equal_operator", true),
+      MATCH_GREATER_THAN("match_greater_than_operator", true),
+      MATCH_GREATER_THAN_OR_EQUAL("match_greater_than_or_equal_operator", true),
+
+      /* Called using "logical array OP integer", apparently. */
+      SLL("sll_operator", true),
+      SLA("sla_operator", true),
+      SRL("srl_operator", true),
+      SRA("sra_operator", true),
+      ROL("rol_operator", true),
+      ROR("ror_operator", true),
+
+      ADDITION("addition_operator", true),
+      SUBSTRACTION("substraction_operator", true),
+      CONCATENATION("concatenation_operator", true),
+      MULTIPLICATION("multiplication_operator", true),
+      DIVISION("division_operator", true),
+      MODULUS("modulus_operator", true),
+      REMAINDER("remainder_operator", true),
+      EXPONENTIATION("exponentiation_operator", true);
+
+      /** Static **************************************************************/
+      private static final Map<String, Operator> FROM_TAG;
+
+      static
+      {
+         final Operator operators[];
+
+         FROM_TAG = new HashMap<String, Operator>();
+
+         operators = Operator.class.getEnumConstants(); /* We Java now... */
+
+         for (final Operator op: operators)
+         {
+            FROM_TAG.put(op.tag, op);
+         }
+      }
+
+      /** Non-Static **********************************************************/
+      private final String tag;
+      private final boolean is_binary;
+
+      private Operator
+      (
+         final String tag,
+         final boolean is_binary
+      )
+      {
+         this.tag = tag;
+         this.is_binary = is_binary;
+      }
+   }
+   /***************************************************************************/
+}