Поддержка внутренних полей и функций у строк

Author: aNNiMON

src/main/java/com/annimon/ownlang/exceptions/UnknownPropertyException.java

@@ -0,0 +1,15 @@
+package com.annimon.ownlang.exceptions;
+
+public final class UnknownPropertyException extends RuntimeException {
+
+    private final String propertyName;
+
+    public UnknownPropertyException(String name) {
+        super("Unknown property " + name);
+        this.propertyName = name;
+    }
+
+    public String getPropertyName() {
+        return propertyName;
+    }
+}

src/main/java/com/annimon/ownlang/lib/StringValue.java

@@ -1,5 +1,6 @@
 package com.annimon.ownlang.lib;
 
+import com.annimon.ownlang.exceptions.UnknownPropertyException;
 import java.util.Objects;
 
 /**
@@ -15,6 +16,19 @@ public final class StringValue implements Value {
     public StringValue(String value) {
         this.value = value;
     }
+
+    public Value access(Value property) {
+        switch (property.asString()) {
+            // Properties
+            case "length":
+                return NumberValue.of(length());
+
+            // Functions
+            case "trim":
+                return new FunctionValue(args -> new StringValue(value.trim()));
+        }
+        throw new UnknownPropertyException(property.asString());
+    }
 
     public int length() {
         return value.length();
@@ -82,5 +96,4 @@ public int compareTo(Value o) {
     public String toString() {
         return asString();
     }
-
 }

src/main/java/com/annimon/ownlang/parser/Parser.java

@@ -782,7 +782,23 @@ private Expression value() {
             return new ValueExpression(createNumber(current.getText(), 16));
         }
         if (match(TokenType.TEXT)) {
-            return new ValueExpression(current.getText());
+            final ValueExpression strExpr = new ValueExpression(current.getText());
+            // "text".property || "text".func()
+            if (lookMatch(0, TokenType.DOT)) {
+                if (lookMatch(1, TokenType.WORD) && lookMatch(2, TokenType.LPAREN)) {
+                    match(TokenType.DOT);
+                    return functionChain(new ContainerAccessExpression(
+                            strExpr, Collections.singletonList(
+                                    new ValueExpression(consume(TokenType.WORD).getText())
+                    )));
+                }
+                final List<Expression> indices = variableSuffix();
+                if (indices.isEmpty()) {
+                    return strExpr;
+                }
+                return new ContainerAccessExpression(strExpr, indices);
+            }
+            return strExpr;
         }
         throw new ParseException("Unknown expression: " + current);
     }

src/main/java/com/annimon/ownlang/parser/ast/ContainerAccessExpression.java

@@ -48,6 +48,9 @@ public Value get() {
 
             case Types.MAP:
                 return ((MapValue) container).get(lastIndex);
+
+            case Types.STRING:
+                return ((StringValue) container).access(lastIndex);
 
             default:
                 throw new TypeException("Array or map expected. Got " + Types.typeToString(container.type()));

src/test/resources/other/stringFunctions.own

@@ -0,0 +1,10 @@
+def testLength() {
+  assertEquals(3, "123".length)
+  s = "test"
+  assertEquals(4, s.length)
+}
+
+def testTrim() {
+  s = "  test   "
+  assertEquals("test", s.trim())
+}