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Diffstat (limited to 'src/recite/parse.rs')
-rw-r--r-- | src/recite/parse.rs | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/recite/parse.rs b/src/recite/parse.rs new file mode 100644 index 0000000..63b16ff --- /dev/null +++ b/src/recite/parse.rs @@ -0,0 +1,135 @@ +/// Add a Verse to a Poem +/// +/// Takes the current word stack, and pushes it onto the stanza. Then, takes +/// the stanza, meter, and some metadata details to create a Verse. That Verse +/// then gets added to the Poem. +/// +/// # Arguments +/// * `$word` - The word stack, used to hold chars dilineated via whitespace +/// * `$stanza` - The stanza stack, used to hold words when they are popped off +/// the word stack +/// * `$cprev` - Indicates this is the second half of a couplet (normally this +/// is just Verse::couplet(prev), but we may need to set it in +/// case of Meter::Read), since this basically just tells the +/// shell to use `$out` in the `task!` macro +/// * `$prev` - The previous verse (or none if there is no previous verse) +/// * `$verses` - The list of verses that make up the poem +/// * `$meter` - The meter corresponding to the verse +#[macro_export] +macro_rules! push { + ($word:expr, $stanza:expr, $cprev:expr, $prev:expr, $verses:expr, $meter:expr) => { + // If there are chars on the word stack, push that word onto the stanza + if !$word.is_empty() { + $stanza.push($word.iter().collect()); + } + + // Check if the last verse was a meter of Read, Write, or + // Addendum, and throw an error if it is + if Verse::rw($prev) && $stanza.is_empty() { + let rw = match $prev.unwrap().meter { + Meter::Read => "read", + Meter::Write => "write", + Meter::Addendum => "append", + _ => "", + }; + eprintln!("dwvsh: parse error: no {} file(s) specified", rw); + return None; + } + + // A meter indicates the end of a verse + if !$stanza.is_empty() { + $verses.push(Verse::new( + Stanza::new($stanza.clone()), + $meter, + $cprev, + Verse::rw($prev), + )); + } + + // Clear the stacks + $stanza.clear(); + $word.clear(); + }; +} + +/// Add a Verse to a Poem, but allow looking ahead by one char +/// +/// This works the exact same as [[push]], except that it doesn't take +/// `$cprev` (since there is no need to set it manually right now), and it +/// takes `$ahead`, which is the next character to look for in the pattern, +/// along with `$aheadm`, which is the corresponding Meter if that `$ahead` is +/// found. +/// +/// # Examples +/// ``` +/// push1!(word, stanza, prev, verses, Meter::Quiet, '&', Meter::And); +/// push1!(word, stanza, prev, verses, Meter::Write, '>', Meter::Addendum); +/// ``` +#[macro_export] +macro_rules! push1 { + ($word:expr, $stanza:expr, $chars:expr, $prev:expr, $verses: expr, $meter:expr, $ahead:expr, $aheadm:expr) => { + // If there are chars on the word stack, push that word + // onto the stanza + if !$word.is_empty() { + $stanza.push($word.iter().collect()); + } + + // Check if the last verse was a meter of Read, Write, or + // Addendum, and throw an error if it is + if Verse::rw($prev) && $stanza.is_empty() { + let rw = match $prev.unwrap().meter { + Meter::Read => "read", + Meter::Write => "write", + Meter::Addendum => "append", + _ => "", + }; + eprintln!("dwvsh: parse error: no {} file(s) specified", rw); + return None; + } + + // Need to peek at the next character, since '>' can mean + // Meter::Write, or '>>' can mean Meter::Addendum + match $chars.clone().peekable().peek() { + // Indicated Meter::Addendum + Some(c) if c == &$ahead => { + // Pop the next character from the input string + // (since we know what it is) + $chars.next(); + + // A meter indicates the end of a verse + $verses.push(Verse::new( + Stanza::new($stanza.clone()), + $aheadm, + Verse::couplet($prev), + Verse::rw($prev), + )); + } + + // Indicates Meter::Write + Some(_) => { + // A meter indicates the end of a verse + $verses.push(Verse::new( + Stanza::new($stanza.clone()), + $meter, + Verse::couplet($prev), + Verse::rw($prev), + )); + } + + // Indicated the end of the input + None => { + // A meter indicates the end of a verse + $verses.push(Verse::new( + Stanza::new($stanza.clone()), + $meter, + Verse::couplet($prev), + Verse::rw($prev), + )); + } + } + + // Clear the stacks + $stanza.clear(); + $word.clear(); + }; +} |