!46 feat: loop 循环实现了 break 关键字的支持

Merge pull request !46 from Luke/feature/add-break-operator

.run/Demo16.run.xml

@@ -2,7 +2,7 @@
   <configuration default="false" name="Demo16" type="Application" factoryName="Application" folderName="Demo">
     <option name="MAIN_CLASS_NAME" value="org.jcnc.snow.cli.SnowCLI" />
     <module name="Snow" />
-    <option name="PROGRAM_PARAMETERS" value="compile run -d playground/Demo/Demo16 -o target/Demo16" />
+    <option name="PROGRAM_PARAMETERS" value="compile run -d playground/Demo/Demo16 -o target/Demo16 --debug" />
     <method v="2">
       <option name="Make" enabled="true" />
     </method>

.run/Demo17.run.xml

@@ -0,0 +1,10 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="Demo17" type="Application" factoryName="Application" folderName="Demo">
+    <option name="MAIN_CLASS_NAME" value="org.jcnc.snow.cli.SnowCLI" />
+    <module name="Snow" />
+    <option name="PROGRAM_PARAMETERS" value="compile run -d playground/Demo/Demo17 -o target/Demo17 --debug" />
+    <method v="2">
+      <option name="Make" enabled="true" />
+    </method>
+  </configuration>
+</component>

.run/测试.run.xml

@@ -7,6 +7,8 @@
     <toRun name="Demo13" type="Application" />
     <toRun name="Demo14" type="Application" />
     <toRun name="Demo15" type="Application" />
+    <toRun name="Demo16" type="Application" />
+    <toRun name="Demo17" type="Application" />
     <toRun name="Demo2" type="Application" />
     <toRun name="Demo3" type="Application" />
     <toRun name="Demo4" type="Application" />

playground/Demo/Demo17/Main.snow

@@ -0,0 +1,23 @@
+module: Main
+    import: os
+    function: main
+        return_type: int
+        body:
+            loop:
+                init:
+                    declare i:int = 1
+                cond:
+                    i <= 10
+                step:
+                    i = i + 1
+                body:
+                    if i % 2 == 0 then
+                        print(i)
+                        break
+                    end if
+                end body
+            end loop
+            return 0
+        end body
+    end function
+end module

playground/Demo/Demo17/OS.snow

@@ -0,0 +1,11 @@
+module: os
+    import: os
+    function: print
+        parameter:
+            declare i1: int
+        return_type: void
+        body:
+            syscall("PRINT",i1)
+        end body
+    end function
+end module

src/main/java/org/jcnc/snow/compiler/ir/builder/StatementBuilder.java

@@ -9,6 +9,7 @@ import org.jcnc.snow.compiler.parser.ast.base.ExpressionNode;
 import org.jcnc.snow.compiler.parser.ast.base.NodeContext;
 import org.jcnc.snow.compiler.parser.ast.base.StatementNode;
 
+import java.util.ArrayDeque;
 import java.util.Locale;
 
 /**
@@ -27,6 +28,10 @@ public class StatementBuilder {
      * 表达式 IR 构建器，用于将表达式节点转为 IR 指令。
      */
     private final ExpressionBuilder expr;
+    /**
+     * break 目标标签栈（保存每层循环的结束标签）
+     */
+    private final ArrayDeque<String> breakTargets = new ArrayDeque<>();
 
     /**
      * 构造方法。
@@ -120,6 +125,14 @@ public class StatementBuilder {
             }
             return;
         }
+        if (stmt instanceof BreakNode) {
+            // break 语句：跳转到当前最近一层循环的结束标签
+            if (breakTargets.isEmpty()) {
+                throw new IllegalStateException("`break` appears outside of a loop");
+            }
+            InstructionFactory.jmp(ctx, breakTargets.peek());
+            return;
+        }
         // 不支持的语句类型
         throw new IllegalStateException("Unsupported statement: " + stmt.getClass().getSimpleName() + ": " + stmt);
     }
@@ -163,8 +176,15 @@ public class StatementBuilder {
 
         // 条件不满足则跳出循环
         emitConditionalJump(loop.cond(), lblEnd);
-        // 构建循环体
+        // 在进入循环体前，记录本层循环的结束标签，供 break 使用
-        buildStatements(loop.body());
+        breakTargets.push(lblEnd);
+        try {
+            // 构建循环体
+            buildStatements(loop.body());
+        } finally {
+            // 离开循环体时弹出标签，避免影响外层
+            breakTargets.pop();
+        }
         // 更新部分（如 for 的 i++）
         if (loop.step() != null) build(loop.step());
 

src/main/java/org/jcnc/snow/compiler/lexer/token/TokenFactory.java

@@ -25,7 +25,7 @@ public class TokenFactory {
     /**
      * 语言的保留关键字集合。
      */
-    private static final Set<String> KEYWORDS = Set.of("module", "function", "parameter", "return_type", "body", "end", "if", "then", "else", "loop", "declare", "return", "import", "init", "cond", "step","globals");
+    private static final Set<String> KEYWORDS = Set.of("module", "function", "parameter", "return_type", "body", "end", "if", "then", "else", "loop", "declare", "return", "import", "init", "cond", "step","globals","break");
 
     /**
      * 内置类型名称集合，如 int、string 等。

src/main/java/org/jcnc/snow/compiler/parser/ast/BreakNode.java

@@ -0,0 +1,16 @@
+package org.jcnc.snow.compiler.parser.ast;
+
+import org.jcnc.snow.compiler.parser.ast.base.NodeContext;
+import org.jcnc.snow.compiler.parser.ast.base.StatementNode;
+
+/**
+ * {@code BreakNode} 表示循环体中的 break 语句。
+ * 出现时应立即终止当前（最内层）循环。
+ */
+public record BreakNode(NodeContext context) implements StatementNode {
+
+    @Override
+    public String toString() {
+        return "break@" + context;
+    }
+}

src/main/java/org/jcnc/snow/compiler/parser/factory/StatementParserFactory.java

@@ -27,6 +27,7 @@ public class StatementParserFactory {
         registry.put("if",      new IfStatementParser());
         registry.put("loop",    new LoopStatementParser());
         registry.put("return",  new ReturnStatementParser());
+        registry.put("break",   new BreakStatementParser());
 
         // 默认处理器: 表达式语句
         registry.put("",        new ExpressionStatementParser());

src/main/java/org/jcnc/snow/compiler/parser/function/ASTPrinter.java

@@ -116,6 +116,7 @@ public class ASTPrinter {
             }
             case ReturnNode r -> System.out.println(pad + "return" +
                     r.getExpression().map(e -> " " + e).orElse(""));
+            case BreakNode _ -> System.out.println(pad + "break");
             case ExpressionStatementNode(ExpressionNode expression, NodeContext _) ->
                     System.out.println(pad + expression);
             case null, default -> System.out.println(pad + n);  // 回退处理

src/main/java/org/jcnc/snow/compiler/parser/statement/BreakStatementParser.java

@@ -0,0 +1,28 @@
+package org.jcnc.snow.compiler.parser.statement;
+
+import org.jcnc.snow.compiler.lexer.token.TokenType;
+import org.jcnc.snow.compiler.parser.ast.BreakNode;
+import org.jcnc.snow.compiler.parser.ast.base.NodeContext;
+import org.jcnc.snow.compiler.parser.context.ParserContext;
+
+/**
+ * 解析 break 语句：仅包含关键字本身，并以换行结束。
+ * 语义：立即终止当前（最内层）循环。
+ */
+public class BreakStatementParser implements StatementParser {
+
+    @Override
+    public BreakNode parse(ParserContext ctx) {
+        // 记录当前位置作为 NodeContext
+        int line = ctx.getTokens().peek().getLine();
+        int column = ctx.getTokens().peek().getCol();
+        String file = ctx.getSourceName();
+
+        // 消耗 'break'
+        ctx.getTokens().expect("break");
+        // 行结束
+        ctx.getTokens().expectType(TokenType.NEWLINE);
+
+        return new BreakNode(new NodeContext(line, column, file));
+    }
+}

src/main/java/org/jcnc/snow/compiler/semantic/analyzers/statement/BreakAnalyzer.java

@@ -0,0 +1,28 @@
+package org.jcnc.snow.compiler.semantic.analyzers.statement;
+
+import org.jcnc.snow.compiler.parser.ast.BreakNode;
+import org.jcnc.snow.compiler.parser.ast.FunctionNode;
+import org.jcnc.snow.compiler.semantic.analyzers.base.StatementAnalyzer;
+import org.jcnc.snow.compiler.semantic.core.Context;
+import org.jcnc.snow.compiler.semantic.core.ModuleInfo;
+import org.jcnc.snow.compiler.semantic.symbol.SymbolTable;
+
+/**
+ * {@code BreakAnalyzer} —— break 语句的语义分析器。
+ * <p>
+ * 目前不做额外检查；是否位于循环体内的限制由 IR 构建阶段（StatementBuilder）
+ * 进行安全校验（若出现在循环外，会抛出清晰的错误）。
+ * 如需在语义阶段提前报错，可在此处结合“循环上下文”进行校验。
+ */
+public class BreakAnalyzer implements StatementAnalyzer<BreakNode> {
+
+    @Override
+    public void analyze(Context ctx,
+                        ModuleInfo mi,
+                        FunctionNode fn,
+                        SymbolTable locals,
+                        BreakNode stmt) {
+        // no-op: break 本身不引入新符号或类型约束
+        // 在语义阶段校验“是否处于循环内”，需要在 ctx 或 SymbolTable 上增加上下文标记后在此检查。
+    }
+}

src/main/java/org/jcnc/snow/compiler/semantic/core/AnalyzerRegistrar.java

@@ -40,6 +40,7 @@ public final class AnalyzerRegistrar {
         registry.registerStatementAnalyzer(LoopNode.class, new LoopAnalyzer());
         registry.registerStatementAnalyzer(ReturnNode.class, new ReturnAnalyzer());
         registry.registerExpressionAnalyzer(BoolLiteralNode.class, new BoolLiteralAnalyzer());
+        registry.registerStatementAnalyzer(BreakNode.class, new BreakAnalyzer());
 
         // 特殊处理: 表达式语句（如 "foo();"）作为语句包装表达式
         registry.registerStatementAnalyzer(ExpressionStatementNode.class,
@@ -56,7 +57,7 @@ public final class AnalyzerRegistrar {
         registry.registerExpressionAnalyzer(BinaryExpressionNode.class, new BinaryExpressionAnalyzer());
 
         // ---------- 注册一元表达式分析器 ----------
-        registry.registerExpressionAnalyzer(UnaryExpressionNode.class,new UnaryExpressionAnalyzer());
+        registry.registerExpressionAnalyzer(UnaryExpressionNode.class, new UnaryExpressionAnalyzer());
 
         // 对尚未实现的表达式类型使用兜底处理器
         registry.registerExpressionAnalyzer(MemberExpressionNode.class,