tiny.smg.tree.scanner.cpp

1const std = @import("std");2const builtin = @import("builtin");34pub const Token = enum(u16) {5    raw_string_delimiter,6    raw_string_content,7};89pub const Valid = packed struct(u8) {10    raw_string_delimiter: bool = false,11    raw_string_content: bool = false,12    _: u6 = 0,13};1415pub const Scanner = struct {16    delimiter_length: u8 = 0,17    delimiter: [maximum_delimiter_length]WChar = @as([maximum_delimiter_length]WChar, @splat(0)),1819    pub const maximum_delimiter_length = 16;20    pub const serialization_buffer_size = 1024;21    pub const WChar: type = switch (builtin.target.os.tag) {22        .windows => u16,23        .macos, .ios, .tvos, .watchos, .visionos => i32,24        .linux, .freebsd => if (builtin.target.cpu.arch.isArm() or builtin.target.cpu.arch.isAARCH64()) u32 else i32,25        else => std.c.wchar_t,26    };2728    pub fn scan(self: *Scanner, lexer: anytype, valid: Valid) bool {29        if (valid.raw_string_delimiter and valid.raw_string_content) return false;3031        if (valid.raw_string_delimiter) {32            lexer.setResult(@backingInt(Token.raw_string_delimiter));33            return self.scanDelimiter(lexer);34        }3536        if (valid.raw_string_content) {37            lexer.setResult(@backingInt(Token.raw_string_content));38            return self.scanContent(lexer);39        }4041        return false;42    }4344    pub fn serialize(self: *const Scanner, buffer: []u8) usize {45        const size = @as(usize, self.delimiter_length) * @sizeOf(WChar);46        std.debug.assert(buffer.len >= size);47        @memcpy(buffer[0..size], std.mem.sliceAsBytes(self.delimiter[0..self.delimiter_length]));48        return size;49    }5051    pub fn deserialize(self: *Scanner, serialized: []const u8) void {52        std.debug.assert(serialized.len % @sizeOf(WChar) == 0);53        const delimiter_length = serialized.len / @sizeOf(WChar);54        std.debug.assert(delimiter_length <= maximum_delimiter_length);55        self.delimiter_length = @intCast(delimiter_length);56        @memcpy(std.mem.sliceAsBytes(self.delimiter[0..delimiter_length]), serialized);57    }5859    fn reset(self: *Scanner) void {60        self.delimiter_length = 0;61        @memset(&self.delimiter, 0);62    }6364    fn scanDelimiter(self: *Scanner, lexer: anytype) bool {65        if (self.delimiter_length > 0) {66            var index: usize = 0;67            while (index < self.delimiter_length) : (index += 1) {68                if (lexer.lookahead() != fromWChar(self.delimiter[index])) return false;69                lexer.advance(false);70            }71            self.reset();72            return true;73        }7475        while (true) {76            if (self.delimiter_length >= maximum_delimiter_length or77                lexer.eof() or78                lexer.lookahead() == '\\' or79                isSpace(lexer.lookahead()))80            {81                return false;82            }83            if (lexer.lookahead() == '(') return self.delimiter_length > 0;84            self.delimiter[self.delimiter_length] = toWChar(lexer.lookahead());85            self.delimiter_length += 1;86            lexer.advance(false);87        }88    }8990    fn scanContent(self: *Scanner, lexer: anytype) bool {91        var delimiter_index: i32 = -1;92        while (true) {93            if (lexer.eof()) {94                lexer.markEnd();95                return true;96            }9798            if (delimiter_index >= 0) {99                if (delimiter_index == self.delimiter_length) {100                    if (lexer.lookahead() == '"') return true;101                    delimiter_index = -1;102                } else if (lexer.lookahead() == fromWChar(self.delimiter[@intCast(delimiter_index)])) {103                    delimiter_index += 1;104                } else {105                    delimiter_index = -1;106                }107            }108109            if (delimiter_index == -1 and lexer.lookahead() == ')') {110                lexer.markEnd();111                delimiter_index = 0;112            }113114            lexer.advance(false);115        }116    }117};118119comptime {120    if (Scanner.maximum_delimiter_length * @sizeOf(Scanner.WChar) >= Scanner.serialization_buffer_size) {121        @compileError("C++ raw string delimiter state exceeds the scanner serialization buffer");122    }123}124125fn isSpace(value: i32) bool {126    return value == ' ' or value >= '\t' and value <= '\r';127}128129fn toWChar(value: i32) Scanner.WChar {130    const Unsigned = @Int(.unsigned, @bitSizeOf(Scanner.WChar));131    const narrowed: Unsigned = @truncate(@as(u32, @bitCast(value)));132    return @bitCast(narrowed);133}134135fn fromWChar(value: Scanner.WChar) i32 {136    return @intCast(value);137}

1pub const cpp = @import("cpp.zig");