Add builtin method calls with no arguments

9 files changed, 55 insertions, 6 deletions

diff --git a/src/main/java/org/zwobble/couscous/ast/CallNode.java b/src/main/java/org/zwobble/couscous/ast/CallNode.java
deleted file mode 100644
index d71c891..0000000
--- a/src/main/java/org/zwobble/couscous/ast/CallNode.java
+++ /dev/null
@@ -1,5 +0,0 @@
-package org.zwobble.couscous.ast;
-
-public class CallNode {
-
-}
diff --git a/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
new file mode 100644
index 0000000..55249a3
--- /dev/null
+++ b/src/main/java/org/zwobble/couscous/ast/MethodCallNode.java
@@ -0,0 +1,20 @@
+package org.zwobble.couscous.ast;
+
+import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
+
+import lombok.Value;
+
+@Value
+public class MethodCallNode implements ExpressionNode {
+    ExpressionNode receiver;
+    String methodName;
+    
+    public static MethodCallNode methodCall(ExpressionNode receiver, String methodName) {
+        return new MethodCallNode(receiver, methodName);
+    }
+    
+    @Override
+    public <T> T accept(ExpressionNodeVisitor<T> visitor) {
+        return visitor.visit(this);
+    }
+}
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java
index 27692e3..f083625 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/ExpressionNodeVisitor.java
@@ -2,6 +2,7 @@ package org.zwobble.couscous.ast.visitors;
 
 import org.zwobble.couscous.ast.Assignment;
 import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.MethodCallNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
 import org.zwobble.couscous.ast.VariableReferenceNode;
 
@@ -10,4 +11,5 @@ public interface ExpressionNodeVisitor<T> {
     T visit(VariableReferenceNode variableReference);
     T visit(Assignment assignment);
     T visit(TernaryConditionalNode ternaryConditional);
+    T visit(MethodCallNode methodCall);
 }
diff --git a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
index 232441c..54a1f60 100644
--- a/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
+++ b/src/main/java/org/zwobble/couscous/interpreter/Evaluator.java
@@ -3,6 +3,7 @@ package org.zwobble.couscous.interpreter;
 import org.zwobble.couscous.ast.Assignment;
 import org.zwobble.couscous.ast.ExpressionNode;
 import org.zwobble.couscous.ast.LiteralNode;
+import org.zwobble.couscous.ast.MethodCallNode;
 import org.zwobble.couscous.ast.TernaryConditionalNode;
 import org.zwobble.couscous.ast.VariableReferenceNode;
 import org.zwobble.couscous.ast.visitors.ExpressionNodeVisitor;
@@ -54,4 +55,11 @@ public class Evaluator implements ExpressionNodeVisitor<InterpreterValue> {
             : ternaryConditional.getIfFalse();
         return eval(branch);
     }
+
+    @Override
+    public InterpreterValue visit(MethodCallNode methodCall) {
+        val receiver = eval(methodCall.getReceiver());
+        // TODO: handle missing methods
+        return receiver.callMethod(methodCall.getMethodName());
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/values/BooleanValue.java b/src/main/java/org/zwobble/couscous/values/BooleanValue.java
index 6d016e6..e6998df 100644
--- a/src/main/java/org/zwobble/couscous/values/BooleanValue.java
+++ b/src/main/java/org/zwobble/couscous/values/BooleanValue.java
@@ -12,4 +12,9 @@ public class BooleanValue implements InterpreterValue {
     public boolean getValue() {
         return value;
     }
+
+    @Override
+    public InterpreterValue callMethod(String methodName) {
+        throw new UnsupportedOperationException();
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/values/IntegerValue.java b/src/main/java/org/zwobble/couscous/values/IntegerValue.java
index 062d137..2bb28d8 100644
--- a/src/main/java/org/zwobble/couscous/values/IntegerValue.java
+++ b/src/main/java/org/zwobble/couscous/values/IntegerValue.java
@@ -5,4 +5,9 @@ import lombok.Value;
 @Value
 public class IntegerValue implements InterpreterValue {
     int value;
+
+    @Override
+    public InterpreterValue callMethod(String methodName) {
+        throw new UnsupportedOperationException();
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/values/InterpreterValue.java b/src/main/java/org/zwobble/couscous/values/InterpreterValue.java
index 64b0e91..7ffebbc 100644
--- a/src/main/java/org/zwobble/couscous/values/InterpreterValue.java
+++ b/src/main/java/org/zwobble/couscous/values/InterpreterValue.java
@@ -1,5 +1,5 @@
 package org.zwobble.couscous.values;
 
 public interface InterpreterValue {
-
+    InterpreterValue callMethod(String methodName);
 }
diff --git a/src/main/java/org/zwobble/couscous/values/StringValue.java b/src/main/java/org/zwobble/couscous/values/StringValue.java
index 1478d41..0e3f626 100644
--- a/src/main/java/org/zwobble/couscous/values/StringValue.java
+++ b/src/main/java/org/zwobble/couscous/values/StringValue.java
@@ -5,4 +5,13 @@ import lombok.Value;
 @Value
 public class StringValue implements InterpreterValue {
     String value;
+
+    @Override
+    public InterpreterValue callMethod(String methodName) {
+        if (methodName == "length") {
+            return new IntegerValue(value.length());
+        } else {
+            throw new UnsupportedOperationException();
+        }
+    }
 }
diff --git a/src/main/java/org/zwobble/couscous/values/UnitValue.java b/src/main/java/org/zwobble/couscous/values/UnitValue.java
index 1cf9dc7..45178dd 100644
--- a/src/main/java/org/zwobble/couscous/values/UnitValue.java
+++ b/src/main/java/org/zwobble/couscous/values/UnitValue.java
@@ -8,4 +8,9 @@ public class UnitValue implements InterpreterValue {
     
     private UnitValue() {
     }
+
+    @Override
+    public InterpreterValue callMethod(String methodName) {
+        throw new UnsupportedOperationException();
+    }
 }