tiny.smg.tree.runtime.language

1const std = @import("std");2const runtime = @import("root.zig");34const abi = runtime.abi;56pub const Mode = struct {7    lex_state: u16,8    external_lex_state: u16,9    reserved_word_set_id: u16,10};1112pub const Entry = struct {13    actions: []const abi.Action,14    reusable: bool,15};1617pub const Language = struct {18    raw: *const abi.Language,1920    pub fn init(raw: *const abi.Language) !Language {21        if (raw.abi_version < 14 or raw.abi_version > 15) return error.UnsupportedGrammarAbi;22        if (raw.lex_fn == null or raw.parse_actions == null) return error.InvalidGrammar;23        return .{ .raw = raw };24    }2526    pub fn symbolName(self: Language, symbol: abi.Symbol) []const u8 {27        if (symbol == abi.error_symbol) return "ERROR";28        if (symbol >= self.raw.symbol_count + self.raw.alias_count) return "";29        return std.mem.span(self.raw.symbol_names.?[symbol]);30    }3132    pub fn symbolMetadata(self: Language, symbol: abi.Symbol) abi.SymbolMetadata {33        if (symbol == abi.error_symbol) return .{ .visible = true, .named = true, .supertype = false };34        return self.raw.symbol_metadata.?[symbol];35    }3637    pub fn publicSymbol(self: Language, symbol: abi.Symbol) abi.Symbol {38        if (symbol == abi.error_symbol) return symbol;39        return self.raw.public_symbol_map.?[symbol];40    }4142    pub fn fieldId(self: Language, name: []const u8) abi.Field {43        var id: abi.Field = 1;44        while (id <= self.raw.field_count) : (id += 1) {45            const pointer = self.raw.field_names.?[id];46            if (@intFromPtr(pointer) == 0) continue;47            const candidate = std.mem.span(@as([*:0]const u8, @ptrCast(pointer)));48            switch (std.mem.order(u8, name, candidate)) {49                .eq => return id,50                .lt => return 0,51                .gt => {},52            }53        }54        return 0;55    }5657    pub fn mode(self: Language, state: abi.State) Mode {58        if (self.raw.abi_version < 15) {59            const modes: [*]const abi.LexMode14 = @ptrCast(@alignCast(self.raw.lex_modes.?));60            const value = modes[state];61            return .{ .lex_state = value.lex_state, .external_lex_state = value.external_lex_state, .reserved_word_set_id = 0 };62        }63        const modes: [*]const abi.LexMode15 = @ptrCast(@alignCast(self.raw.lex_modes.?));64        const value = modes[state];65        return .{ .lex_state = value.lex_state, .external_lex_state = value.external_lex_state, .reserved_word_set_id = value.reserved_word_set_id };66    }6768    pub fn lookup(self: Language, state: abi.State, symbol: abi.Symbol) u16 {69        if (state < self.raw.large_state_count) {70            return self.raw.parse_table.?[@as(usize, state) * self.raw.symbol_count + symbol];71        }72        var index: usize = self.raw.small_parse_table_map.?[state - self.raw.large_state_count];73        const table = self.raw.small_parse_table.?;74        const group_count = table[index];75        index += 1;76        for (0..group_count) |_| {77            const value = table[index];78            const symbol_count = table[index + 1];79            index += 2;80            for (0..symbol_count) |_| {81                if (table[index] == symbol) return value;82                index += 1;83            }84        }85        return 0;86    }8788    pub fn entry(self: Language, state: abi.State, symbol: abi.Symbol) Entry {89        if (symbol == abi.error_symbol) return .{ .actions = &.{}, .reusable = false };90        const index = self.lookup(state, symbol);91        const values = self.raw.parse_actions.?;92        const header = values[index].entry;93        const actions: [*]const abi.Action = @ptrCast(&values[index + 1]);94        return .{ .actions = actions[0..header.count], .reusable = header.reusable };95    }9697    pub fn hasActions(self: Language, state: abi.State, symbol: abi.Symbol) bool {98        return self.lookup(state, symbol) != 0;99    }100101    pub fn nextState(self: Language, state: abi.State, symbol: abi.Symbol) abi.State {102        if (symbol < self.raw.token_count) {103            const actions = self.entry(state, symbol).actions;104            if (actions.len == 0) return 0;105            const action = actions[actions.len - 1];106            if (action.type != @backingInt(abi.ActionType.shift)) return 0;107            return if (action.shift.extra) state else action.shift.state;108        }109        return self.lookup(state, symbol);110    }111112    pub fn aliases(self: Language, production: u16) []const abi.Symbol {113        if (production == 0 or self.raw.max_alias_sequence_length == 0) return &.{};114        const start = @as(usize, production) * self.raw.max_alias_sequence_length;115        return self.raw.alias_sequences.?[start .. start + self.raw.max_alias_sequence_length];116    }117118    pub fn fieldMap(self: Language, production: u16) []const abi.FieldMapEntry {119        if (self.raw.field_count == 0) return &.{};120        const slice = self.raw.field_map_slices.?[production];121        return self.raw.field_map_entries.?[slice.index .. slice.index + slice.length];122    }123124    pub fn isReserved(self: Language, lexer_mode: Mode, symbol: abi.Symbol) bool {125        if (lexer_mode.reserved_word_set_id == 0 or self.raw.reserved_words == null) return false;126        const start = @as(usize, lexer_mode.reserved_word_set_id) * self.raw.max_reserved_word_set_size;127        for (self.raw.reserved_words.?[start .. start + self.raw.max_reserved_word_set_size]) |word| {128            if (word == symbol) return true;129            if (word == 0) return false;130        }131        return false;132    }133134    pub fn externalValid(self: Language, state: u16) []const bool {135        if (state == 0 or self.raw.external_token_count == 0) return &.{};136        const start = @as(usize, state) * self.raw.external_token_count;137        return self.raw.external_scanner.states.?[start .. start + self.raw.external_token_count];138    }139};

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