tiny.zen.code

1const std = @import("std");2const html = @import("html.zig");3const syntax = @import("syntax.zig");45const Allocator = std.mem.Allocator;67pub const Options = struct {8    highlighting: bool = true,9    line_numbers: bool = true,10    titles: bool = true,11    language_labels: bool = true,12    word_wrap: bool = true,13};1415pub const Info = struct {16    language: []const u8 = "",17    title: []const u8 = "",18};1920pub fn parseInfo(info: []const u8) Info {21    const trimmed = std.mem.trim(u8, info, " \t");22    if (trimmed.len == 0) return .{};23    const language = firstWord(trimmed);24    const rest = std.mem.trim(u8, trimmed[language.len..], " \t");25    if (rest.len == 0) return .{ .language = language };26    if (parseTitle(rest)) |title| return .{ .language = language, .title = title };27    if (onlyRenderOptions(rest)) return .{ .language = language };28    return .{ .language = language, .title = rest };29}3031pub fn render(32    allocator: Allocator,33    out: *std.ArrayList(u8),34    info_text: []const u8,35    source: []const u8,36    options: Options,37) !void {38    const info = parseInfo(info_text);39    const anchors = optionValue(info_text, "anchors") orelse "";40    const exact_source = hasOption(info_text, "source", "exact");41    const wide = exact_source or hasOption(info_text, "role", "wide");42    try out.appendSlice(allocator, "<div class=\"zen-code-block");43    if (options.word_wrap) {44        try out.appendSlice(allocator, " zen-code-wrap");45    } else {46        try out.appendSlice(allocator, " zen-code-nowrap");47    }48    if (!options.line_numbers) try out.appendSlice(allocator, " zen-code-no-lines");49    if (exact_source) {50        try out.appendSlice(allocator, " zen-source-listing zen-role-wide");51    } else if (wide) {52        try out.appendSlice(allocator, " zen-code-longform zen-role-wide");53    } else {54        try out.appendSlice(allocator, " zen-code-example zen-role-reading");55    }56    try out.append(allocator, '"');57    if (info.language.len != 0) {58        try out.appendSlice(allocator, " data-language=\"");59        try html.appendAttributeEscaped(out, allocator, info.language);60        try out.append(allocator, '"');61    }62    if (exact_source) {63        try out.appendSlice(allocator, " data-source=\"exact\"");64    }65    try out.append(allocator, '>');66    if ((options.titles and info.title.len != 0) or (options.language_labels and info.language.len != 0)) {67        try out.appendSlice(allocator, "<div class=\"zen-code-header\">");68        if (options.titles and info.title.len != 0) {69            try out.appendSlice(allocator, "<span class=\"zen-code-title\">");70            try html.appendEscaped(out, allocator, info.title);71            try out.appendSlice(allocator, "</span>");72        }73        if (options.language_labels and info.language.len != 0) {74            try out.appendSlice(allocator, "<span class=\"zen-code-language\">");75            try html.appendEscaped(out, allocator, info.language);76            try out.appendSlice(allocator, "</span>");77        }78        try out.appendSlice(allocator, "</div>");79    }80    try out.appendSlice(allocator, "<pre class=\"zen-code\"><code");81    if (info.language.len != 0) {82        try out.appendSlice(allocator, " class=\"language-");83        try html.appendAttributeEscaped(out, allocator, info.language);84        try out.append(allocator, '"');85    }86    try out.append(allocator, '>');87    try appendLines(allocator, out, info.language, source, anchors, options);88    try out.appendSlice(allocator, "</code></pre></div>\n");89}9091fn appendLines(92    allocator: Allocator,93    out: *std.ArrayList(u8),94    language: []const u8,95    source: []const u8,96    anchors: []const u8,97    options: Options,98) !void {99    var highlighter = syntax.Highlighter.init(language, options.highlighting);100    var anchor_cursor = AnchorCursor{ .encoded = anchors };101    if (source.len == 0) {102        try appendLine(allocator, out, &highlighter, &anchor_cursor, "", 1, options);103        try anchor_cursor.finish();104        return;105    }106    var start: usize = 0;107    var number: usize = 1;108    while (start < source.len) : (number += 1) {109        const end = std.mem.indexOfScalarPos(u8, source, start, '\n') orelse source.len;110        try appendLine(111            allocator,112            out,113            &highlighter,114            &anchor_cursor,115            source[start..end],116            number,117            options,118        );119        if (end == source.len) break;120        start = end + 1;121    }122    try anchor_cursor.finish();123}124125fn appendLine(126    allocator: Allocator,127    out: *std.ArrayList(u8),128    highlighter: *syntax.Highlighter,129    anchors: *AnchorCursor,130    line: []const u8,131    number: usize,132    options: Options,133) !void {134    try out.appendSlice(allocator, "<span class=\"zen-code-line\">");135    try anchors.appendForLine(allocator, out, number);136    if (options.line_numbers) {137        try out.appendSlice(allocator, "<span class=\"zen-code-line-number\" aria-hidden=\"true\">");138        try appendUsize(out, allocator, number);139        try out.appendSlice(allocator, "</span>");140    }141    try out.appendSlice(allocator, "<span class=\"zen-code-line-source\">");142    try highlighter.appendLine(out, allocator, line);143    try out.appendSlice(allocator, "</span></span>");144}145146const AnchorCursor = struct {147    encoded: []const u8,148    cursor: usize = 0,149150    fn appendForLine(151        self: *AnchorCursor,152        allocator: Allocator,153        out: *std.ArrayList(u8),154        line: usize,155    ) !void {156        while (self.cursor < self.encoded.len) {157            const end = std.mem.indexOfScalarPos(158                u8,159                self.encoded,160                self.cursor,161                ',',162            ) orelse self.encoded.len;163            const entry = self.encoded[self.cursor..end];164            const split = std.mem.indexOfScalar(u8, entry, ':') orelse165                return error.InvalidData;166            const target = std.fmt.parseInt(usize, entry[0..split], 10) catch167                return error.InvalidData;168            if (target == 0 or target < line) return error.InvalidData;169            if (target > line) return;170            const anchor = entry[split + 1 ..];171            if (anchor.len == 0) return error.InvalidData;172            try out.appendSlice(allocator, "<span id=\"");173            try html.appendAttributeEscaped(out, allocator, anchor);174            try out.appendSlice(allocator, "\"></span>");175            self.cursor = end + @intFromBool(end < self.encoded.len);176        }177    }178179    fn finish(self: AnchorCursor) !void {180        if (self.cursor != self.encoded.len) return error.InvalidData;181    }182};183184fn onlyRenderOptions(value: []const u8) bool {185    var cursor: usize = 0;186    var count: usize = 0;187    while (nextToken(value, &cursor)) |token| {188        if (!std.mem.startsWith(u8, token, "anchors=") and189            !std.mem.eql(u8, token, "source=exact") and190            !std.mem.eql(u8, token, "role=reading") and191            !std.mem.eql(u8, token, "role=wide")) return false;192        count += 1;193    }194    return count != 0;195}196197fn hasOption(info: []const u8, key: []const u8, expected: []const u8) bool {198    const value = optionValue(info, key) orelse return false;199    return std.mem.eql(u8, value, expected);200}201202fn optionValue(info: []const u8, key: []const u8) ?[]const u8 {203    const trimmed = std.mem.trim(u8, info, " \t");204    var cursor: usize = firstWord(trimmed).len;205    while (nextToken(trimmed, &cursor)) |token| {206        const split = std.mem.indexOfScalar(u8, token, '=') orelse continue;207        if (std.mem.eql(u8, token[0..split], key)) return token[split + 1 ..];208    }209    return null;210}211212fn nextToken(value: []const u8, cursor: *usize) ?[]const u8 {213    while (cursor.* < value.len and214        (value[cursor.*] == ' ' or value[cursor.*] == '\t')) : (cursor.* += 1)215    {}216    if (cursor.* == value.len) return null;217    const start = cursor.*;218    cursor.* = skipToken(value, cursor.*);219    return value[start..cursor.*];220}221222fn parseTitle(rest: []const u8) ?[]const u8 {223    var cursor: usize = 0;224    while (cursor < rest.len) {225        while (cursor < rest.len and (rest[cursor] == ' ' or rest[cursor] == '\t')) : (cursor += 1) {}226        if (cursor >= rest.len) return null;227        if (std.mem.startsWith(u8, rest[cursor..], "title=")) {228            const value_start = cursor + "title=".len;229            if (value_start >= rest.len) return "";230            const quote = rest[value_start];231            if (quote == '"' or quote == '\'') {232                const text_start = value_start + 1;233                const text_end = std.mem.indexOfScalarPos(u8, rest, text_start, quote) orelse rest.len;234                return rest[text_start..text_end];235            }236            var end = value_start;237            while (end < rest.len and rest[end] != ' ' and rest[end] != '\t') : (end += 1) {}238            return rest[value_start..end];239        }240        cursor = skipToken(rest, cursor);241    }242    return null;243}244245fn skipToken(value: []const u8, start: usize) usize {246    var index = start;247    while (index < value.len and value[index] != ' ' and value[index] != '\t') {248        if (value[index] == '"' or value[index] == '\'') {249            const quote = value[index];250            index += 1;251            while (index < value.len and value[index] != quote) : (index += 1) {}252        }253        if (index < value.len) index += 1;254    }255    return index;256}257258fn firstWord(value: []const u8) []const u8 {259    var end: usize = 0;260    while (end < value.len and value[end] != ' ' and value[end] != '\t') : (end += 1) {}261    return value[0..end];262}263264fn appendUsize(out: *std.ArrayList(u8), allocator: Allocator, value: usize) Allocator.Error!void {265    var buffer: [20]u8 = undefined;266    const text = std.fmt.bufPrint(&buffer, "{d}", .{value}) catch unreachable;267    try out.appendSlice(allocator, text);268}269270test "code parses fence language and titles" {271    try std.testing.expectEqualDeep(Info{ .language = "zig", .title = "Comptime DSL" }, parseInfo("zig title=\"Comptime DSL\""));272    try std.testing.expectEqualDeep(Info{ .language = "c", .title = "C API smoke" }, parseInfo("c C API smoke"));273    try std.testing.expectEqualDeep(274        Info{ .language = "zig" },275        parseInfo("zig source=exact anchors=1:member/field/Doc/empty"),276    );277}278279test "code renders highlighted titled numbered lines" {280    var out: std.ArrayList(u8) = .empty;281    defer out.deinit(std.testing.allocator);282    try render(std.testing.allocator, &out, "zig title=\"Example\"", "const x: u8 = 1;\n", .{});283    try std.testing.expect(std.mem.indexOf(284        u8,285        out.items,286        "<div class=\"zen-code-block zen-code-wrap " ++287            "zen-code-example zen-role-reading\" data-language=\"zig\">",288    ) != null);289    try std.testing.expect(std.mem.indexOf(u8, out.items, "<span class=\"zen-code-title\">Example</span>") != null);290    try std.testing.expect(std.mem.indexOf(u8, out.items, "<span class=\"zen-code-line-number\" aria-hidden=\"true\">1</span>") != null);291    try std.testing.expect(std.mem.indexOf(u8, out.items, "<span class=\"zen-code-keyword\">const</span>") != null);292    try std.testing.expect(std.mem.indexOf(u8, out.items, "<span class=\"zen-code-type\">u8</span>") != null);293    try std.testing.expect(std.mem.indexOf(u8, out.items, "<span class=\"zen-code-number\">1</span>") != null);294}295296test "code places typed anchors on exact source lines" {297    var out: std.ArrayList(u8) = .empty;298    defer out.deinit(std.testing.allocator);299    try render(300        std.testing.allocator,301        &out,302        "zig source=exact anchors=1:member/field/Doc/empty," ++303            "2:member/field/Doc/text",304        "empty,\ntext: []const u8,\n",305        .{},306    );307    try std.testing.expect(std.mem.indexOf(308        u8,309        out.items,310        "data-source=\"exact\"",311    ) != null);312    try std.testing.expect(std.mem.indexOf(313        u8,314        out.items,315        "zen-source-listing zen-role-wide",316    ) != null);317    try std.testing.expect(std.mem.indexOf(318        u8,319        out.items,320        "id=\"member/field/Doc/empty\"",321    ) != null);322    try std.testing.expect(std.mem.indexOf(323        u8,324        out.items,325        "id=\"member/field/Doc/text\"",326    ) != null);327    try std.testing.expect(std.mem.indexOf(u8, out.items, "anchors=") == null);328}329330test "code gives authored wide blocks a distinct semantic role" {331    var out: std.ArrayList(u8) = .empty;332    defer out.deinit(std.testing.allocator);333    try render(std.testing.allocator, &out, "text role=wide", "dense\n", .{});334    try std.testing.expect(std.mem.indexOf(335        u8,336        out.items,337        "zen-code-longform zen-role-wide",338    ) != null);339    try std.testing.expect(std.mem.indexOf(u8, out.items, "zen-code-example") == null);340}341342test "code rejects invalid and out of range source anchors" {343    var out: std.ArrayList(u8) = .empty;344    defer out.deinit(std.testing.allocator);345    try std.testing.expectError(346        error.InvalidData,347        render(std.testing.allocator, &out, "zig anchors=0:zero", "value\n", .{}),348    );349    out.clearRetainingCapacity();350    try std.testing.expectError(351        error.InvalidData,352        render(std.testing.allocator, &out, "zig anchors=2:late", "value\n", .{}),353    );354}

1/// Code-fence metadata, syntax highlighting, and HTML rendering.2pub const code = @import("code.zig");