feat(): support math block

1 files changed, 56 insertions, 0 deletions

diff --git a/src/math.zig b/src/math.zig
new file mode 100644
index 0000000..e28b3b9
--- /dev/null
+++ b/src/math.zig
@@ -0,0 +1,56 @@
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const Token = @import("lexer/Token.zig");
+const Lexer = @import("lexer/Lexer.zig");
+const Element = @import("eval/Element.zig");
+const testing = @import("testing.zig");
+const doTest = testing.doMath;
+const doTestError = testing.doError;
+
+pub const Error = error{InvalidMathBlock} || Allocator.Error;
+
+pub fn parse(alloc: Allocator, l: *Lexer) Error!Element {
+    _ = l.next();
+    const beg = l.next() orelse return Error.InvalidMathBlock;
+    if (!beg.kind.isDelimiter()) return Error.InvalidMathBlock;
+    const math = try Element.Math.Block.init(alloc);
+    var acc = try std.ArrayList(u8).initCapacity(alloc, 2);
+    while (l.next()) |it| {
+        if (it.kind == .math_block) return Error.InvalidMathBlock;
+        try acc.appendSlice(alloc, it.content);
+        // restore modifications done by the lexer
+        if (it.kind.requiresSpace())
+            try acc.append(alloc, ' ');
+        if (it.kind.isDelimiter()) {
+            const next = l.peek() orelse return Error.InvalidMathBlock;
+            if (next.kind == .math_block) break;
+        }
+    }
+    var end = l.next() orelse return Error.InvalidMathBlock;
+    if (end.kind != .math_block) return Error.InvalidMathBlock;
+    const el = try Element.Figure.init(alloc, math.element());
+    math.content = try acc.toOwnedSlice(alloc);
+    end = l.next() orelse return el.element();
+    if (!end.kind.isDelimiter()) return Error.InvalidMathBlock;
+    return el.element();
+}
+
+test {
+    const alloc = std.testing.allocator;
+
+    try doTest(parse, alloc,
+        \\$$$
+        \\x
+        \\$$$
+    , "<figure>" ++ @embedFile("data/test_block_1.svg") ++ "</figure>");
+    try doTest(parse, alloc,
+        \\$$$
+        \\x^2
+        \\$$$
+    , "<figure>" ++ @embedFile("data/test_block_2.svg") ++ "</figure>");
+    try doTest(parse, alloc,
+        \\$$$
+        \\forall x in RR, quad f(x) = x^2
+        \\$$$
+    , "<figure>" ++ @embedFile("data/test_block_3.svg") ++ "</figure>");
+}