Continued work on List.eval, general function/macro/special form invocation.

src/edu/utexas/cs345/jdblisp/FunctionEntry.java

@@ -9,8 +9,35 @@ public class FunctionEntry {
     protected final Symbol[] parameters;
     protected final SExp body;
 
-    public SExp call(SymbolTable symbolTable, Seq seq) {
+    public FunctionEntry(Symbol[] parameters, SExp body) {
-        // TODO
+        this.parameters = parameters;
-        return null;
+        this.body = body;
+    }
+
+    public SExp call(SymbolTable symbolTable, Seq arguments) throws LispException {
+
+        // bind arguments to parameters
+        SymbolTable localScope = new SymbolTable(symbolTable);
+        int i = 0
+        while (i < parameters.length) {
+
+            // too few arguments
+            if (arguments == null)
+                throw new InvalidArgumentQuantityException(
+                    parameters.length, i);
+
+            // bind one arg to param
+            localScope.bind(parameters[i], new VariableEntry(arguments.car));
+
+            arguments = arguments.cdr;
+            ++i;
+        }
+
+        // too many arguments
+        if (arguments != null)
+            throw new InvalidArgumentQuantityException(parameters.length,
+                (i + arguments.length()));
+
+        return body.eval(localScope);
     }
 }

src/edu/utexas/cs345/jdblisp/InvalidArgumentQuantityException.java

@@ -0,0 +1,13 @@
+package edu.utexas.cs345.jdb-lisp;
+
+/**
+ * InvalidArgumentQuantityException
+ * Indicates a call to a form with an incorrect number of arguments.
+ */
+public class InvalidArgumentQuantityException extends LispException {
+
+    public InvalidArgumentQuantityException(int expected, int actual) {
+        super ("Invalid number of arguments: " + actual
+            + " (expected " + expected + ").");
+    }
+}

src/edu/utexas/cs345/jdblisp/Lisp.java

@@ -14,8 +14,9 @@ import edu.utexas.cs345.jdblisp.parser.ParseException;
  */
 public class Lisp {
 
+    public SymbolTable globalSymbolTable;
+
     private Parser parser;
-    private SymbolTable globalSymbolTable;
     private boolean interactive = true;
 
     public Lisp() {

src/edu/utexas/cs345/jdblisp/List.java

@@ -17,29 +17,16 @@ public class List implements SExp {
             // then that symbol is the name of an operator
             // Depending on the funciton binding of the operator in the
             // current lexical environment the form is either:
+
             // a special form
             // a macro form or
             // a function form
 
             // look up in the symbol table
-            TableEntry functionEntry = table.findFunction((Symbol) seq.car);
+            FunctionEntry functionEntry = table.lookupFunction((Symbol) seq.car);
-
-            // check parameter length
-            if (functionEntry.parameters.length != seq.cdr.length())
-                throw new LispException("Invalid number of parameters: "
-                    + seq.cdr.length());
-
-            // create a new SymbolTable and bind arguments to parameters
-            SymbolTable newTable = table;
-            Seq nextArg = seq.cdr;
-            for (Symbol parameter : functionEntry.parameters) {
-                TableEntry newEntry = new TableEntry(parameter, null, nextArg.car);
-                newTable = new SymbolTable(newEntry, newTable);
-                nextArg = nextArg.cdr;
-            }
 
             // call function
-            return functionEntry.body.eval(newTable);
+            return functionEntry.call(table);
 
         }
 

src/edu/utexas/cs345/jdblisp/SpecialForms.java

@@ -1,14 +1,101 @@
 package edu.utexas.cs345.jdblisp;
 
+import java.util.ArrayList;
+
 /**
- * SpecialForms
+ * SpecialFormEntry
  * @author Jonathan Bernard (jdbernard@gmail.com)
  */
-public class SpecialForms {
+public abstract class SpecialFormEntry extends FunctionEntry {
 
-    public static SymbolTable createTable() {
+    protected Lisp environment;
 
+    public SpecialFormEntry(Lisp environment) { this.environment = environment; }
+
+    public abstract SExp call(SymbolTable symbolTable, Seq arguments) throws LispException;
+
+
+    public static definSpecialForms(Lisp environment) {
+    
+        SpecialFormEntry DEFUN = new SpecialFormEntry(environment) {
+            public SExp call(SymbolTable symbolTable, Seq arguments) throws LispException {
+
+                Symbol functionName;
+                ArrayList<Symbol> parameters;
+                SExp body;
+
+                // TODO: check to see if a function for this symbol exists
+                // and warn if so
+
+                if (arguments.length() != 3)
+                    new InvalidArgumentQuantityException(3, arguments.length());
+
+                // first argument: Symbol for function name
+                if (!(arguments.car instanceof Symbol))
+                    // TODO: error: has to be a symbol
+
+                functionName = (Symbol) arguments.car;
+
+                // second argument, parameter list
+                arguments = arguments.cdr;
+                assert (arguments != null);
+                
+                if (!(arguments.car instanceof List))
+                    // TODO: error, need parameter list
+
+                // read parameters
+                parameters = new ArrayList<Symbol>();
+                Seq paramSeq = ((List) arguments.car).seq;
+                while (seq != null) {
+                    if (!(seq.car instanceof Symbol))
+                        // TODO: error, expected symbol
+
+                    parameters.add((Symbol) seq.car);
+                    seq = seq.cdr;
+                }
+
+                // third argument: function body
+                arguments = arguments.cdr;
+                assert (arguments != null);
+
+                // TODO: necessary? if (!(arguments.car instanceof List))
+                
+                body = arguments.car;
+
+                environment.globalSymbolTable.define(functionName,
+                    new FunctionEntry(parameters.toArray(new Symbol[]{}), body));
+
+                return functionName;
+            }
+        };
+
+        SpecialFormEntry SETQ = new SpecialFormEntry(environment) throws LispException {
+            public SExp call(SymbolTable symbolTable, Seq arguments) {
+                
+                Symbol variableName;
+                SExp variableValue;
+
+                // TODO: check for redifinition of variable (and warn)
+
+                if (arguments.length() != 2)
+                    throw new InvalidArgumentQuantityException(2,
+                        arguments.length());
+
+                // first argument: Symbol for variable name
+                if (!(arguments.car instanceof Symbol))
+                    // TODO: error: expected symbol
+
+                variableName = (Symbol) arguments.car;
+
+                // second argument: variable value
+                arguments = arguments.cdr;
+                assert (arguments != null);
+
+                variableValue = arguments.car;
+            }
+        };
+
+        environment.globalSymbolTable.defin(new Symbol("DEFUN"), DEFUN);
+        environment.globalSymbolTable.defin(new Symbol("SETQ"), SETQ);
     }
-
-    public static TableEntry 
 }

src/edu/utexas/cs345/jdblisp/SymbolTable.java

@@ -20,7 +20,7 @@ public class SymbolTable {
         this.locked = locked;
     }
 
-    public Symbol defineFunction(Symbol s, FunctionEntry f) {
+    public Symbol bind(Symbol s, FunctionEntry f) {
         if (functions.get(s) != null) {
             // TODO: warning: function redefinition
             // Also, check access permissions
@@ -29,7 +29,7 @@ public class SymbolTable {
         return s;
     }
 
-    public Symbol defineVariable(Symbol s, VariableEntry v) {
+    public Symbol bind(Symbol s, VariableEntry v) {
         if (variables.get(s) != null) {
             // TODO: warning: variable redefinition
             // Also, check access permissions

src/edu/utexas/cs345/jdblisp/VariableEntry.java

@@ -8,6 +8,8 @@ public class VariableEntry {
 
     protected final SExp expression;
 
+    public VariableEntry(SExp expression) { this.expression = expression; }
+    
     public SExp eval(SymbolTable symbolTable) {
         return expression.eval(symbolTable);
     }