Errors

Every package exception implements Alto\FrontMatter\Exception\FrontMatterExceptionInterface, allowing one catch for decoding, access, and rendering failures.

<?php
use Alto\FrontMatter\Exception\FrontMatterExceptionInterface;
use Alto\FrontMatter\FrontMatter;

try {
    $metadata = FrontMatter::fromString($document);
} catch (FrontMatterExceptionInterface $error) {
    // Report or reject invalid front matter.
}

SyntaxError::line() and column() are one-based source coordinates inside the raw front matter block:

<?php
use Alto\FrontMatter\Exception\SyntaxError;

try {
    FrontMatter::fromString("---\ntitle: [unterminated\n---\n");
} catch (SyntaxError $error) {
    printf('%d:%d %s', $error->line(), $error->column(), $error->getMessage());
}

fromFile() throws RuntimeException when its path cannot be read. That error is outside the package exception interface because it is an I/O failure rather than a front matter failure.