1 files changed, 42 insertions, 17 deletions

diff --git a/src/jq/codegen.zig b/src/jq/codegen.zig
index 21c5832..6ca5382 100644
--- a/src/jq/codegen.zig
+++ b/src/jq/codegen.zig
@@ -1,9 +1,10 @@
 const std = @import("std");
 const jv = @import("../jv.zig");
+const ConstIndex = @import("./constant_table.zig").ConstIndex;
 const Ast = @import("./parse.zig").Ast;
 const BinaryOp = @import("./parse.zig").BinaryOp;
 
-pub const ConstIndex = enum(u32) { _ };
+pub const VariableIndex = enum(u32) { _ };
 
 pub const Opcode = enum {
     nop,
@@ -11,6 +12,7 @@ pub const Opcode = enum {
     jump,
     jump_unless,
     fork,
+    backtrack,
     dup,
     pop,
     subexp_begin,
@@ -30,8 +32,9 @@ pub const Opcode = enum {
     ge,
     alt,
     @"const",
-    const_true,
-    const_false,
+    load,
+    store,
+    append,
 };
 
 pub const Instr = union(Opcode) {
@@ -42,6 +45,7 @@ pub const Instr = union(Opcode) {
     jump: usize,
     jump_unless: usize,
     fork: usize,
+    backtrack,
     dup,
     pop,
     subexp_begin,
@@ -61,8 +65,9 @@ pub const Instr = union(Opcode) {
     ge,
     alt,
     @"const": ConstIndex,
-    const_true,
-    const_false,
+    load: VariableIndex,
+    store: VariableIndex,
+    append: VariableIndex,
 
     pub fn op(self: Self) Opcode {
         return self;
@@ -72,11 +77,13 @@ pub const Instr = union(Opcode) {
 const Codegen = struct {
     instrs: std.ArrayList(Instr),
     allocator: std.mem.Allocator,
+    variables_count: usize,
 
     fn init(allocator: std.mem.Allocator) !Codegen {
         return .{
             .instrs = try std.ArrayList(Instr).initCapacity(allocator, 16),
             .allocator = allocator,
+            .variables_count = 0,
         };
     }
 
@@ -122,12 +129,12 @@ const Codegen = struct {
                 //     POP
                 //     <rhs>
                 //     JUMP_UNLESS l1
-                //     CONST_TRUE
+                //     CONST true
                 //     JUMP l2
-                // l1: CONST_FALSE
+                // l1: CONST false
                 // l2: JUMP l4
                 // l3: POP
-                //     CONST_FALSE
+                //     CONST false
                 // l4:
                 try self.emit(.dup);
                 try self.generate(and_expr.lhs);
@@ -137,17 +144,17 @@ const Codegen = struct {
                 try self.generate(and_expr.rhs);
                 const jump2_idx = self.pos();
                 try self.emit(.{ .jump_unless = 0 });
-                try self.emit(.const_true);
+                try self.emit(.{ .@"const" = .true });
                 const jump3_idx = self.pos();
                 try self.emit(.{ .jump = 0 });
                 const l1 = self.pos();
-                try self.emit(.const_false);
+                try self.emit(.{ .@"const" = .false });
                 const jump4_idx = self.pos();
                 const l2 = self.pos();
                 try self.emit(.{ .jump = 0 });
                 const l3 = self.pos();
                 try self.emit(.pop);
-                try self.emit(.const_false);
+                try self.emit(.{ .@"const" = .false });
                 const l4 = self.pos();
 
                 self.patchLabel(jump1_idx, l3);
@@ -160,21 +167,21 @@ const Codegen = struct {
                 //     <lhs>
                 //     JUMP_UNLESS l1
                 //     POP
-                //     CONST_TRUE
+                //     CONST true
                 //     JUMP l3
                 // l1: POP
                 //     <rhs>
                 //     JUMP_UNLESS l2
-                //     CONST_TRUE
+                //     CONST true
                 //     JUMP l3
-                // l2: CONST_FALSE
+                // l2: CONST false
                 // l3:
                 try self.emit(.dup);
                 try self.generate(or_expr.lhs);
                 const jump1_idx = self.pos();
                 try self.emit(.{ .jump_unless = 0 });
                 try self.emit(.pop);
-                try self.emit(.const_true);
+                try self.emit(.{ .@"const" = .true });
                 const jump2_idx = self.pos();
                 try self.emit(.{ .jump = 0 });
                 const l1 = self.pos();
@@ -182,11 +189,11 @@ const Codegen = struct {
                 try self.generate(or_expr.rhs);
                 const jump3_idx = self.pos();
                 try self.emit(.{ .jump_unless = 0 });
-                try self.emit(.const_true);
+                try self.emit(.{ .@"const" = .true });
                 const jump4_idx = self.pos();
                 try self.emit(.{ .jump = 0 });
                 const l2 = self.pos();
-                try self.emit(.const_false);
+                try self.emit(.{ .@"const" = .false });
                 const l3 = self.pos();
 
                 self.patchLabel(jump1_idx, l1);
@@ -215,6 +222,24 @@ const Codegen = struct {
                 self.patchLabel(fork_index, l1);
                 self.patchLabel(jump_index, l2);
             },
+            .construct_array => |arr| {
+                // DUP
+                // CONST []
+                // STORE v
+                // <items>
+                // APPEND v
+                // BACKTRACK
+                // LOAD v
+                const v: VariableIndex = @enumFromInt(self.variables_count);
+                self.variables_count += 1;
+                try self.emit(.dup);
+                try self.emit(.{ .@"const" = .empty_array });
+                try self.emit(.{ .store = v });
+                try self.generate(arr.items);
+                try self.emit(.{ .append = v });
+                try self.emit(.backtrack);
+                try self.emit(.{ .load = v });
+            },
         }
     }