From 71dba5c77d82298975fae5d4ee6ae330ef3da799 Mon Sep 17 00:00:00 2001
From: Luna <git@l4.pm>
Date: Sun, 2 Jun 2019 00:23:50 -0300
Subject: [PATCH] vm: add greater and less

---
 src/chunk.zig    |  6 ++++++
 src/compiler.zig |  1 -
 src/vm.zig       | 15 +++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/chunk.zig b/src/chunk.zig
index 31985eb..50aca63 100644
--- a/src/chunk.zig
+++ b/src/chunk.zig
@@ -183,6 +183,12 @@ pub const Chunk = struct {
             return try simpleInstruction(stdout, "OP_FALSE", index);
         } else if (instruction == OpCode.Not) {
             return try simpleInstruction(stdout, "OP_NOT", index);
+        } else if (instruction == OpCode.Equal) {
+            return try simpleInstruction(stdout, "OP_EQUAL", index);
+        } else if (instruction == OpCode.Greater) {
+            return try simpleInstruction(stdout, "OP_GREATER", index);
+        } else if (instruction == OpCode.Less) {
+            return try simpleInstruction(stdout, "OP_LESS", index);
         } else {
             try stdout.print("Unknown opcode: {}\n", instruction);
             return index + 1;
diff --git a/src/compiler.zig b/src/compiler.zig
index 17b8a0b..459adda 100644
--- a/src/compiler.zig
+++ b/src/compiler.zig
@@ -221,7 +221,6 @@ pub const Compiler = struct {
 
     /// Emits bytecode for a number being loaded into the code.
     fn number(self: *Compiler) !void {
-        std.debug.warn("parsing number: '{}'\n", self.parser.previous.lexeme);
         var value: f64 = try std.fmt.parseFloat(
             f64,
             self.parser.previous.lexeme,
diff --git a/src/vm.zig b/src/vm.zig
index d712897..1fbf0ac 100644
--- a/src/vm.zig
+++ b/src/vm.zig
@@ -143,6 +143,18 @@ pub const VM = struct {
         try self.push(values.NumberVal(a / b));
     }
 
+    fn doGreater(self: *VM) !void {
+        var b = try self.popNum();
+        var a = try self.popNum();
+        try self.push(values.BoolVal(a > b));
+    }
+
+    fn doLess(self: *VM) !void {
+        var b = try self.popNum();
+        var a = try self.popNum();
+        try self.push(values.BoolVal(a < b));
+    }
+
     fn runtimeError(self: *VM, comptime fmt: []const u8, args: ...) void {
         std.debug.warn(fmt, args);
         std.debug.warn("\n[line {}] in script\n", self.chk.lines[self.ip]);
@@ -186,6 +198,9 @@ pub const VM = struct {
                     try self.push(values.BoolVal(valuesEqual(a, b)));
                 },
 
+                chunk.OpCode.Greater => try self.doGreater(),
+                chunk.OpCode.Less => try self.doLess(),
+
                 chunk.OpCode.Add => try self.doAdd(),
                 chunk.OpCode.Subtract => try self.doSub(),
                 chunk.OpCode.Multiply => try self.doMul(),