screen: start drm implementation

1 files changed, 28 insertions, 0 deletions

diff --git a/src/estd/parser/common.zig b/src/estd/parser/common.zig
new file mode 100644
index 0000000..986af58
--- /dev/null
+++ b/src/estd/parser/common.zig
@@ -0,0 +1,28 @@
+const std = @import("std");
+const root = @import("root.zig");
+const Context = @import("context.zig").Context;
+const ParseFn = root.ParseFn;
+
+pub fn LiteralFn(comptime I: type, comptime O: type) type {
+    return *const fn (comptime literal: []const I, value: O) ParseFn(I, O);
+}
+
+pub fn Literal(comptime I: type, comptime O: type) LiteralFn(I, O) {
+    return struct {
+        pub fn literal(comptime lit: []const I, value: O) ParseFn(I, O) {
+            return struct {
+                pub fn parse(ctx: *Context(I)) !O {
+                    const snapshot = ctx.cursor.snapshot();
+                    errdefer ctx.cursor.rollback(snapshot);
+
+                    const slice = try ctx.cursor.consume(lit.len);
+                    if (std.mem.eql(I, lit, slice)) {
+                        return value;
+                    }
+
+                    return error.UnexpectedLiteral;
+                }
+            }.parse;
+        }
+    }.literal;
+}