Chapter 15: Arrayslinear-chapter15

Co-authored-by: XmiliaH <xmilia.hermit@gmail.com>
Co-authored-by: Thalia Archibald <thalia@archibald.dev>
Co-authored-by: Robert Obkircher <robert.obkircher@gmail.com>

1 files changed, 81 insertions, 0 deletions

diff --git a/src/test/java/com/seaofnodes/simple/BrainFuckTest.java b/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
new file mode 100644
index 00000000..f7c66bda
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/BrainFuckTest.java
@@ -0,0 +1,81 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.evaluator.Evaluator;
+import com.seaofnodes.simple.node.StopNode;
+import org.junit.Test;
+import org.junit.Ignore;
+
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class BrainFuckTest {
+
+    @Ignore
+    @Test
+    public void testBrainfuck() {
+        var program = "++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.".getBytes(StandardCharsets.UTF_8);
+        var encoded = new StringBuilder("u8[] program = new u8[").append(program.length).append("];");
+        for (int i = 0; i < program.length; i++) {
+            int value = program[i] & 0xFF;
+            encoded.append("program[").append(i).append("] = ").append(value).append(";");
+        }
+
+        Parser parser = new Parser(
+                encoded + """
+int pc = 0;
+int d = 0;
+u8[] data = new u8[100];
+u8[] output = new u8[0];
+
+while (pc < program#) {
+    int command = program[pc];
+    if (command == 62) {
+        d = d + 1;
+    } else if (command == 60) {
+        d = d - 1;
+    } else if (command == 43) {
+        data[d] = data[d] + 1;
+    } else if (command == 45) {
+        data[d] = data[d] - 1;
+    } else if (command == 46) {
+        u8[] old = output;
+        output = new u8[output# + 1];
+        int i = 0;
+        while (i < old#) {
+            output[i] = old[i];
+            i = i + 1;
+        }
+        output[i] = data[d];
+    } else if (command == 44) {
+        data[d] = 42;
+    } else if (command == 91) {
+        if (data[d] == 0) {
+            int d = 1;
+            while (d > 0) {
+                pc = pc + 1;
+                command = program[pc];
+                if (command == 91) d = d + 1;
+                if (command == 93) d = d - 1;
+            }
+        }
+    } else if (command == 93) {
+        if (data[d] != 0) {
+            int d = 1;
+            while (d > 0) {
+                pc = pc - 1;
+                command = program[pc];
+                if (command == 93) d = d + 1;
+                if (command == 91) d = d - 1;
+            }
+        }
+    }
+    pc = pc + 1;
+}
+return output;
+                """);
+        StopNode stop = parser.parse(false).iterate(false);
+        assertEquals("Hello World!\n", Evaluator.evaluate(stop, 0, 10000).toString());
+    }
+}