fix unit tests

1 files changed, 53 insertions, 42 deletions

diff --git a/src/grammar.zig b/src/grammar.zig
index 3c586f3..9b794a0 100644
--- a/src/grammar.zig
+++ b/src/grammar.zig
@@ -1,12 +1,12 @@
 const std = @import("std");
 
+const Rule = @import("rule.zig");
 const Character = @import("character.zig").Character;
 const NonTerminal = @import("non-terminal.zig");
 
 const Self = @This();
 
 non_terminals: []NonTerminal,
-entry_id: usize,
 allocator: std.mem.Allocator,
 
 pub fn parse(entry: []const u8, buffer: []const u8, allocator: std.mem.Allocator) !Self {
@@ -18,19 +18,30 @@ pub fn parse(entry: []const u8, buffer: []const u8, allocator: std.mem.Allocator
 		const name = try NonTerminal.parse_name(line);
 
 		if (!names.contains(name)) {
-			try names.put(name, names.count());
+			try names.put(name, names.count() + 1);
 		}
 	}
 
 	lines = std.mem.tokenizeScalar(u8, buffer, '\n');
 	var self = Self {
-		.non_terminals = try allocator.alloc(NonTerminal, names.count()),
-		.entry_id = names.get(entry) orelse return error.MissingRule,
+		.non_terminals = try allocator.alloc(NonTerminal, names.count() + 1),
 		.allocator = allocator,
 	};
 	errdefer self.deinit();
 
 	{
+		self.non_terminals[0] = try NonTerminal.init("_start", 0, allocator);
+		const init_rule = try allocator.alloc(Character, 1);
+		init_rule[0] = Character {
+			.non_terminal = names.get(entry) orelse return error.MissingRule,
+		};
+
+		try self.non_terminals[0].add_rule(Rule {
+			.items = init_rule
+		});
+	}
+
+	{
 		var iterator = names.iterator();
 		while (iterator.next()) |name_entry| {
 			self.non_terminals[name_entry.value_ptr.*] = try NonTerminal.init(
@@ -68,7 +79,7 @@ pub inline fn non_terminal_by_id(self: *Self, id: usize) *NonTerminal {
 }
 
 pub inline fn entry_point(self: *Self) *NonTerminal {
-	return self.non_terminal_by_id(self.entry_id);
+	return self.non_terminal_by_id(0);
 }
 
 fn generate_first(self: *Self) void {
@@ -254,17 +265,17 @@ test "expr" {
 	var grammar = try Self.parse("S", text, allocator);
 	defer grammar.deinit();
 
-	try grammar.non_terminal_by_id(0).first.expect(&[_]u9 { '(', 'a', 'b' });
-	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { '+', Character.EPSILON });
-	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { '(', 'a', 'b' });
-	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { '*', Character.EPSILON });
-	try grammar.non_terminal_by_id(4).first.expect(&[_]u9 { '(', 'a', 'b' });
+	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { '(', 'a', 'b' });
+	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { '+', Character.EPSILON });
+	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { '(', 'a', 'b' });
+	try grammar.non_terminal_by_id(4).first.expect(&[_]u9 { '*', Character.EPSILON });
+	try grammar.non_terminal_by_id(5).first.expect(&[_]u9 { '(', 'a', 'b' });
 
-	try grammar.non_terminal_by_id(0).follows.expect(&[_]u9 { ')', Character.END });
 	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { ')', Character.END });
-	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { '+', ')', Character.END });
+	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { ')', Character.END });
 	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { '+', ')', Character.END });
-	try grammar.non_terminal_by_id(4).follows.expect(&[_]u9 { '*', '+', ')', Character.END });
+	try grammar.non_terminal_by_id(4).follows.expect(&[_]u9 { '+', ')', Character.END });
+	try grammar.non_terminal_by_id(5).follows.expect(&[_]u9 { '*', '+', ')', Character.END });
 }
 
 test "sample 0" {
@@ -279,15 +290,15 @@ test "sample 0" {
 	var grammar = try Self.parse("S", text, allocator);
 	defer grammar.deinit();
 
-	try grammar.non_terminal_by_id(0).first.expect(&[_]u9 { 'd', 'g', 'h', 'b', 'a', Character.EPSILON });
-	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'd', 'g', 'h', Character.EPSILON });
-	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'g', Character.EPSILON });
-	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'h', Character.EPSILON });
+	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'd', 'g', 'h', 'b', 'a', Character.EPSILON });
+	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'd', 'g', 'h', Character.EPSILON });
+	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'g', Character.EPSILON });
+	try grammar.non_terminal_by_id(4).first.expect(&[_]u9 { 'h', Character.EPSILON });
 
-	try grammar.non_terminal_by_id(0).follows.expect(&[_]u9 { Character.END });
-	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { 'g', 'h', Character.END });
-	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'a', 'g', 'h', Character.END });
-	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { 'b', 'g', 'h', Character.END });
+	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { Character.END });
+	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'g', 'h', Character.END });
+	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { 'a', 'g', 'h', Character.END });
+	try grammar.non_terminal_by_id(4).follows.expect(&[_]u9 { 'b', 'g', 'h', Character.END });
 }
 
 test "sample 1" {
@@ -303,13 +314,13 @@ test "sample 1" {
 	var grammar = try Self.parse("S", text, allocator);
 	defer grammar.deinit();
 
-	try grammar.non_terminal_by_id(0).first.expect(&[_]u9 { 'a' });
-	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'c', Character.EPSILON });
-	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'd', Character.EPSILON });
+	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'a' });
+	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'c', Character.EPSILON });
+	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'd', Character.EPSILON });
 
-	try grammar.non_terminal_by_id(0).follows.expect(&[_]u9 { Character.END });
-	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { 'b', 'd' });
-	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'b' });
+	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { Character.END });
+	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'b', 'd' });
+	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { 'b' });
 }
 
 test "sample 2" {
@@ -329,17 +340,17 @@ test "sample 2" {
 	var grammar = try Self.parse("S", text, allocator);
 	defer grammar.deinit();
 
-	try grammar.non_terminal_by_id(0).first.expect(&[_]u9 { 'a', 'c', 'e' });
-	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'a', 'c' });
-	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'd' });
-	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'e', Character.EPSILON });
-	try grammar.non_terminal_by_id(4).first.expect(&[_]u9 { 'f', Character.EPSILON });
+	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'a', 'c', 'e' });
+	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'a', 'c' });
+	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'd' });
+	try grammar.non_terminal_by_id(4).first.expect(&[_]u9 { 'e', Character.EPSILON });
+	try grammar.non_terminal_by_id(5).first.expect(&[_]u9 { 'f', Character.EPSILON });
 
-	try grammar.non_terminal_by_id(0).follows.expect(&[_]u9 { Character.END });
-	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { 'd' });
-	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { Character.END });
+	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { Character.END });
+	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'd' });
 	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { Character.END });
-	try grammar.non_terminal_by_id(4).follows.expect(&[_]u9 { 'a' });
+	try grammar.non_terminal_by_id(4).follows.expect(&[_]u9 { Character.END });
+	try grammar.non_terminal_by_id(5).follows.expect(&[_]u9 { 'a' });
 }
 
 test "sample 3" {
@@ -357,11 +368,11 @@ test "sample 3" {
 	var grammar = try Self.parse("S", text, allocator);
 	defer grammar.deinit();
 
-	try grammar.non_terminal_by_id(0).first.expect(&[_]u9 { 'a', 'b', 'c', Character.EPSILON });
-	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'a', 'c' });
-	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'a', 'b' });
+	try grammar.non_terminal_by_id(1).first.expect(&[_]u9 { 'a', 'b', 'c', Character.EPSILON });
+	try grammar.non_terminal_by_id(2).first.expect(&[_]u9 { 'a', 'c' });
+	try grammar.non_terminal_by_id(3).first.expect(&[_]u9 { 'a', 'b' });
 
-	try grammar.non_terminal_by_id(0).follows.expect(&[_]u9 { 'd', Character.END });
-	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { 'a', 'b', 'c', 'd' });
-	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'a', 'b', 'c', 'd', Character.END });
+	try grammar.non_terminal_by_id(1).follows.expect(&[_]u9 { 'd', Character.END });
+	try grammar.non_terminal_by_id(2).follows.expect(&[_]u9 { 'a', 'b', 'c', 'd' });
+	try grammar.non_terminal_by_id(3).follows.expect(&[_]u9 { 'a', 'b', 'c', 'd', Character.END });
 }