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-rw-r--r--src/grammar.zig95
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 });
}
generated by cgit v1.2.3-70-g09d2 (git 2.53.0) at 2026-05-12 17:10:10 +0000