Implement break and continue

Author: mdbrnowski

interpreter.py

@@ -6,6 +6,11 @@
 from utils.memory import MemoryStack
 from utils.values import Int, Float, String, Vector
 
+class Break(Exception):
+    pass
+
+class Continue(Exception):
+    pass
 
 class Interpreter(MyParserVisitor):
     def __init__(self):
@@ -36,7 +41,12 @@ def visitForLoop(self, ctx: MyParser.ForLoopContext):
         while a <= b:
             self.memory_stack.put(variable, Int(a))
             a = a + 1  # to increment enumerateor and disregard changes inside the loop
-            self.visit(ctx.statement())
+            try:
+                self.visit(ctx.statement())
+            except Continue:
+                continue
+            except Break:
+                break
 
     def visitRange(self, ctx: MyParser.RangeContext):
         a = self.visit(ctx.expression(0))
@@ -47,7 +57,12 @@ def visitRange(self, ctx: MyParser.RangeContext):
 
     def visitWhileLoop(self, ctx: MyParser.WhileLoopContext):
         while self.visit(ctx.comparison()):
-            self.visit(ctx.statement())
+            try:
+                self.visit(ctx.statement())
+            except Continue:
+                continue
+            except Break:
+                break
 
     def visitComparison(self, ctx: MyParser.ComparisonContext):
         a = self.visit(ctx.expression(0))
@@ -153,10 +168,10 @@ def visitSpecialMatrixFunction(self, ctx: MyParser.SpecialMatrixFunctionContext)
             return vector
 
     def visitBreak(self, ctx: MyParser.BreakContext):
-        return self.visitChildren(ctx)  # todo
+        raise Break()
 
     def visitContinue(self, ctx: MyParser.ContinueContext):
-        return self.visitChildren(ctx)  # todo
+        raise Continue()
 
     def visitVector(self, ctx: MyParser.VectorContext):
         elements = [

test_main.py

@@ -84,6 +84,7 @@ def test_sem_errors(name: str, line_numbers: list[int], additional: str):
         ("variables", [2, 1, 3, "OK", 6]),
         ("while", [4, 3, 2, 1, 0]),
         ("for", [1, 10, 2, 10, 3, 10, 4, 10]),
+        ("break_continue", [1, 2, 1, 2, 4] * 2),
     ],
 )
 def test_interpreter(name: str, output: str):

tests/interpreter/break_continue.txt

@@ -0,0 +1,27 @@
+for i = 1:4 {
+    if (i == 3)
+        break;
+    print i;
+}
+
+for i = 1:4 {
+    if (i == 3)
+        continue;
+    print i;
+}
+
+i = 0;
+while (i < 4) {
+    i += 1;
+    if (i == 3)
+        break;
+    print i;
+}
+
+i = 0;
+while (i < 4) {
+    i += 1;
+    if (i == 3)
+        continue;
+    print i;
+}