tiny.zen.math.mathml

1const std = @import("std");2const zen = @import("../root.zig");3const parse = @import("parse.zig");45const html = zen.html;6const Allocator = std.mem.Allocator;78pub fn append(out: *std.ArrayList(u8), allocator: Allocator, node: parse.Node) Allocator.Error!void {9    switch (node) {10        .row => |items| {11            if (items.len == 1) return append(out, allocator, items[0]);12            try out.appendSlice(allocator, "<mrow>");13            for (items) |item| try append(out, allocator, item);14            try out.appendSlice(allocator, "</mrow>");15        },16        .ident => |ident| {17            if (ident.upright) {18                try out.appendSlice(allocator, "<mi mathvariant=\"normal\">");19            } else {20                try out.appendSlice(allocator, "<mi>");21            }22            try html.appendEscaped(out, allocator, ident.text);23            try out.appendSlice(allocator, "</mi>");24        },25        .number => |text| {26            try out.appendSlice(allocator, "<mn>");27            try html.appendEscaped(out, allocator, text);28            try out.appendSlice(allocator, "</mn>");29        },30        .operator => |operator| {31            try out.appendSlice(allocator, "<mo");32            if (operator.stretchy) try out.appendSlice(allocator, " stretchy=\"true\"");33            if (operator.rigid) try out.appendSlice(allocator, " stretchy=\"false\"");34            if (operator.movable_word) try out.appendSlice(allocator, " movablelimits=\"true\"");35            try out.append(allocator, '>');36            try html.appendEscaped(out, allocator, operator.text);37            try out.appendSlice(allocator, "</mo>");38        },39        .space => |width| {40            try out.appendSlice(allocator, "<mspace width=\"");41            try out.appendSlice(allocator, width);42            try out.appendSlice(allocator, "\"/>");43        },44        .text => |text| {45            try out.appendSlice(allocator, "<mtext>");46            try html.appendEscaped(out, allocator, text);47            try out.appendSlice(allocator, "</mtext>");48        },49        .frac => |frac| {50            try out.appendSlice(allocator, "<mfrac>");51            try append(out, allocator, frac.first.*);52            try append(out, allocator, frac.second.*);53            try out.appendSlice(allocator, "</mfrac>");54        },55        .radical => |radical| {56            if (radical.index) |index| {57                try out.appendSlice(allocator, "<mroot>");58                try append(out, allocator, radical.radicand.*);59                try append(out, allocator, index.*);60                try out.appendSlice(allocator, "</mroot>");61            } else {62                try out.appendSlice(allocator, "<msqrt>");63                try append(out, allocator, radical.radicand.*);64                try out.appendSlice(allocator, "</msqrt>");65            }66        },67        .scripts => |scripts| {68            const tag = scriptTag(scripts);69            try out.append(allocator, '<');70            try out.appendSlice(allocator, tag);71            try out.append(allocator, '>');72            try append(out, allocator, scripts.base.*);73            if (scripts.sub) |sub| try append(out, allocator, sub.*);74            if (scripts.sup) |sup| try append(out, allocator, sup.*);75            try out.appendSlice(allocator, "</");76            try out.appendSlice(allocator, tag);77            try out.append(allocator, '>');78        },79        .accent => |accent| {80            try out.appendSlice(allocator, "<mover accent=\"true\">");81            try append(out, allocator, accent.base.*);82            try out.appendSlice(allocator, "<mo>");83            try html.appendEscaped(out, allocator, accent.mark);84            try out.appendSlice(allocator, "</mo></mover>");85        },86        .table => |table| try appendTable(out, allocator, table),87    }88}8990fn appendTable(out: *std.ArrayList(u8), allocator: Allocator, table: parse.Table) Allocator.Error!void {91    const fenced = table.env.open != null or table.env.close != null;92    if (fenced) try out.appendSlice(allocator, "<mrow>");93    if (table.env.open) |text| try appendFence(out, allocator, text);94    try out.appendSlice(allocator, "<mtable");95    if (table.env.display_cells) try out.appendSlice(allocator, " displaystyle=\"true\"");96    if (table.env.class) |class| {97        try out.appendSlice(allocator, " class=\"");98        try out.appendSlice(allocator, class);99        try out.append(allocator, '"');100    }101    try out.append(allocator, '>');102    for (table.rows) |row| {103        try out.appendSlice(allocator, "<mtr>");104        for (row) |cell| {105            try out.appendSlice(allocator, "<mtd>");106            for (cell.row) |item| try append(out, allocator, item);107            try out.appendSlice(allocator, "</mtd>");108        }109        try out.appendSlice(allocator, "</mtr>");110    }111    try out.appendSlice(allocator, "</mtable>");112    if (table.env.close) |text| try appendFence(out, allocator, text);113    if (fenced) try out.appendSlice(allocator, "</mrow>");114}115116fn appendFence(out: *std.ArrayList(u8), allocator: Allocator, text: []const u8) Allocator.Error!void {117    try out.appendSlice(allocator, "<mo stretchy=\"true\">");118    try html.appendEscaped(out, allocator, text);119    try out.appendSlice(allocator, "</mo>");120}121122fn scriptTag(scripts: parse.Scripts) []const u8 {123    const both = scripts.sub != null and scripts.sup != null;124    if (scripts.limits) {125        if (both) return "munderover";126        return if (scripts.sub != null) "munder" else "mover";127    }128    if (both) return "msubsup";129    return if (scripts.sub != null) "msub" else "msup";130}131132test "mathml emits scripts by placement preference" {133    var parsed = try parse.parse(std.testing.allocator, "\\sum_{i}^{n} x_i", null);134    defer parsed.deinit();135    var out: std.ArrayList(u8) = .empty;136    defer out.deinit(std.testing.allocator);137    try append(&out, std.testing.allocator, parsed.root);138    try std.testing.expectEqualStrings(139        "<mrow><munderover><mo>∑</mo><mi>i</mi><mi>n</mi></munderover>" ++140            "<msub><mi>x</mi><mi>i</mi></msub></mrow>",141        out.items,142    );143}144145test "mathml emits fenced matrices" {146    var parsed = try parse.parse(std.testing.allocator, "\\begin{pmatrix} a & b \\\\ & 1 \\end{pmatrix}", null);147    defer parsed.deinit();148    var out: std.ArrayList(u8) = .empty;149    defer out.deinit(std.testing.allocator);150    try append(&out, std.testing.allocator, parsed.root);151    try std.testing.expectEqualStrings(152        "<mrow><mo stretchy=\"true\">(</mo><mtable>" ++153            "<mtr><mtd><mi>a</mi></mtd><mtd><mi>b</mi></mtd></mtr>" ++154            "<mtr><mtd></mtd><mtd><mn>1</mn></mtd></mtr>" ++155            "</mtable><mo stretchy=\"true\">)</mo></mrow>",156        out.items,157    );158}159160test "mathml emits cases with a lone brace and class" {161    var parsed = try parse.parse(std.testing.allocator, "\\begin{cases} x & y \\end{cases}", null);162    defer parsed.deinit();163    var out: std.ArrayList(u8) = .empty;164    defer out.deinit(std.testing.allocator);165    try append(&out, std.testing.allocator, parsed.root);166    try std.testing.expectEqualStrings(167        "<mrow><mo stretchy=\"true\">{</mo><mtable class=\"zen-cases\">" ++168            "<mtr><mtd><mi>x</mi></mtd><mtd><mi>y</mi></mtd></mtr>" ++169            "</mtable></mrow>",170        out.items,171    );172}173174test "mathml emits aligned with display cells" {175    var parsed = try parse.parse(std.testing.allocator, "\\begin{aligned} a &= b \\\\ &= c \\end{aligned}", null);176    defer parsed.deinit();177    var out: std.ArrayList(u8) = .empty;178    defer out.deinit(std.testing.allocator);179    try append(&out, std.testing.allocator, parsed.root);180    try std.testing.expectEqualStrings(181        "<mtable displaystyle=\"true\" class=\"zen-aligned\">" ++182            "<mtr><mtd><mi>a</mi></mtd><mtd><mo>=</mo><mi>b</mi></mtd></mtr>" ++183            "<mtr><mtd></mtd><mtd><mo>=</mo><mi>c</mi></mtd></mtr>" ++184            "</mtable>",185        out.items,186    );187}188189test "mathml escapes text content" {190    var parsed = try parse.parse(std.testing.allocator, "a < b \\text{ & so }", null);191    defer parsed.deinit();192    var out: std.ArrayList(u8) = .empty;193    defer out.deinit(std.testing.allocator);194    try append(&out, std.testing.allocator, parsed.root);195    try std.testing.expectEqualStrings(196        "<mrow><mi>a</mi><mo>&lt;</mo><mi>b</mi><mtext> &amp; so </mtext></mrow>",197        out.items,198    );199}

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