Don't require zero before dot (#49)

Author: iam4722202468

modules/mql/src/main/java/net/hollowcube/mql/parser/MqlParser.java

@@ -7,6 +7,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import static net.hollowcube.mql.parser.MqlToken.Type.NUMBER;
+
 public class MqlParser {
     private final MqlLexer lexer;
 
@@ -89,6 +91,12 @@ public MqlParser(@NotNull String source) {
         if (token == null) throw new MqlParseError("unexpected end of input");
 
         return switch (token.type()) {
+            case DOT -> {
+                var next = lexer.next();
+                if (next == null) throw new MqlParseError("unexpected end of input");
+                if (next.type() != NUMBER) throw new MqlParseError("expected number after .");
+                yield new MqlNumberExpr(Double.parseDouble("0." + lexer.span(next)));
+            }
             case NUMBER -> new MqlNumberExpr(Double.parseDouble(lexer.span(token)));
             case IDENT -> new MqlIdentExpr(lexer.span(token));
             case MINUS -> {

modules/mql/src/test/java/net/hollowcube/mql/TestMql.java

@@ -38,6 +38,21 @@ public void basicQueryCall() {
         assertEquals(1, ((MqlNumberValue) result).value());
     }
 
+    @Test
+    public void testDot() {
+        var source = ".1 + 10 + 10 + .3";
+
+        var expr = new MqlParser(source).parse();
+        var scopeImpl = new MqlScopeImpl();
+        var vars = new MqlScopeImpl.Mutable();
+
+        var scope = new MqlScriptScope(scopeImpl, vars, scopeImpl);
+        var result = expr.evaluate(scope);
+
+        assertTrue(result instanceof MqlNumberValue);
+        assertEquals(20.4, ((MqlNumberValue) result).value(), 0.0001);
+    }
+
     @Test
     public void testAdd() {
         var source = "10 + 10 + 10";