Handle STDERR, in addition to STDOUT

This patch overhauls the reading and reciting of verses, such that the
redirection of STDERR (in addition to STDOUT, which was already a
feature), is now possible.

Removed the 'stdout' argument from recite(), since it is no longer
needed with how incantations function.

A verse's couplet indicator is now a u8, instead of a bool, with certain
values corresponding to types of couplets, for instance:

  ls | grep Ca | lolcat
  ^    ^         ^
  |    |         2: right side of a couplet
  |    3: both sides of a couplet
  1: left side of a couplet

Incantions are no longer hanlded in rune.rs, and the task macros have
been removed. Now, a verse incants itself, matching on its own meter to
determine how to handle the next verse.

The following runes were added to help with handling STDERR:
  Write2 -> 2>
  WriteAll -> &>
  Addendum2 -> 2>>
  AddendumAll -> &>>

The 'io' field in verse was changed from an Option<Rune>, to an array of
Runes, since a single verse might have multiple IO operations.

The following fields were added to Verse, to assist with handling
STDERR:
  ip -> List of filenames to read into STDIN
  op -> List of filenames to send STDOUT to
  ep -> List of filenames to send STDERR to

Keep track of channels when reading a poem. Channels are relating to IO
operations. If channel is None, words get pushed to the verse's primary
stanza (i.e. the verb or the clause). If a channel is selected, words
are pushed to one of the aforementioned new fields in Verse.
  Read -> ip
  Write/Addedum -> op
  Write2/Addedum2 -> ep
  WriteAll/AddendumAll -> op and ep

1 files changed, 4 insertions, 30 deletions

diff --git a/src/poem/recite.rs b/src/poem/recite.rs
index 60b7857..8b2fd1d 100644
--- a/src/poem/recite.rs
+++ b/src/poem/recite.rs
@@ -1,4 +1,3 @@
-mod ps;
 use super::Poem;
 use crate::compose::Environment;
 use crate::path;
@@ -12,14 +11,11 @@ use std::{
 };
 
 pub trait Reciteable {
-    fn recite(&self, env: &mut Environment, stdout: Option<bool>) -> Result<Vec<u8>, io::Error>;
+    fn recite(&self, env: &mut Environment) -> Result<Vec<u8>, io::Error>;
 }
 
 impl Reciteable for Poem {
-    fn recite(&self, env: &mut Environment, stdout: Option<bool>) -> Result<Vec<u8>, io::Error> {
-        // Should we print to stdout or always capture it
-        let stdout = stdout.unwrap_or(true);
-
+    fn recite(&self, env: &mut Environment) -> Result<Vec<u8>, io::Error> {
         // Variable for storing the output of a piped verse
         let mut out: Vec<u8> = Vec::new();
 
@@ -94,7 +90,7 @@ impl Reciteable for Poem {
                             Some(poem) => poem,
                             None => break, // TODO: Return an error
                         };
-                        let mut out = poem.recite(env, Some(false))?;
+                        let mut out = poem.recite(env)?;
                         match out.last() {
                             Some(last) => {
                                 if *last == b'\n' {
@@ -165,29 +161,7 @@ impl Reciteable for Poem {
                     continue;
                 }
 
-                // Incant the verse, based on its meter
-                if stdout {
-                    match verse.io {
-                        Rune::Read => Rune::incant_read(&mut verse, &mut out, &mut pids)?,
-                        Rune::Write => Rune::incant_write(&mut verse, &mut out, &mut pids)?,
-                        Rune::Addendum => Rune::incant_addendum(&mut verse, &mut out, &mut pids)?,
-                        _ => match verse.meter {
-                            Rune::None => Rune::incant_none(&verse, &mut out)?,
-                            Rune::Couplet => Rune::incant_couplet(&verse, &mut out)?,
-                            Rune::Quiet => Rune::incant_quiet(&verse, &mut out, &mut pids)?,
-                            Rune::And => Rune::incant_and(&verse, &mut out)?,
-                            Rune::Continue => Rune::incant_continue(&verse, &mut out)?,
-                            _ => unreachable!(),
-                        },
-                    }
-                } else {
-                    match verse.io {
-                        Rune::Read => Rune::incant_read(&mut verse, &mut out, &mut pids)?,
-                        Rune::Write => Rune::incant_write(&mut verse, &mut out, &mut pids)?,
-                        Rune::Addendum => Rune::incant_addendum(&mut verse, &mut out, &mut pids)?,
-                        _ => Rune::incant_couplet(&verse, &mut out)?,
-                    }
-                }
+                verse.incant(&mut out, &mut pids)?
             };
 
             // Break from the loop if the meter is not [Rune::Continue], and