From 521cacbaf4460c26000f353e15c9865e4c6be9df Mon Sep 17 00:00:00 2001
From: Lyle Mantooth <lyle@menteeth.us>
Date: Sun, 4 Feb 2024 12:09:24 -0500
Subject: [PATCH] Parse out variants from MML.

---
 src/mfvi.rs | 104 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)

diff --git a/src/mfvi.rs b/src/mfvi.rs
index 346ac8b..919371b 100644
--- a/src/mfvi.rs
+++ b/src/mfvi.rs
@@ -1,8 +1,65 @@
+use std::collections::{BTreeMap, HashSet};
+
+#[derive(Clone, Copy)]
+pub enum SfxMode {
+    Off,
+    On,
+}
+
 struct Translation<'a> {
     find: &'a str,
     replacement: &'a str,
 }
 
+#[derive(Clone)]
+pub struct Variant<'v> {
+    keep_delim: &'v str,
+    remove_delims: HashSet<&'v str>,
+}
+
+impl<'v> Variant<'v> {
+    pub fn ignores(&self) -> &HashSet<&str> {
+        &self.remove_delims
+    }
+}
+
+pub struct VariantList<'v> {
+    all_delims: HashSet<&'v str>,
+    variants: BTreeMap<&'v str, Variant<'v>>,
+}
+
+impl<'v> VariantList<'v> {
+    fn new() -> Self {
+        VariantList {
+            all_delims: HashSet::new(),
+            variants: BTreeMap::new(),
+        }
+    }
+
+    fn finish(mut self) -> Self {
+        for (_, v) in self.variants.iter_mut() {
+            v.remove_delims = self.all_delims.clone();
+            v.remove_delims.remove(v.keep_delim);
+        }
+
+        if self.variants.is_empty() {
+            self.variants.insert(
+                "_default_",
+                Variant {
+                    keep_delim: "",
+                    remove_delims: self.all_delims.clone(),
+                },
+            );
+        }
+
+        self
+    }
+
+    pub fn get(&self, name: &str) -> Option<&Variant> {
+        self.variants.get(name)
+    }
+}
+
 pub fn replace_chars(input: &str) -> String {
     let trs: Vec<Translation<'_>> = input
         .lines()
@@ -26,3 +83,50 @@ pub fn replace_chars(input: &str) -> String {
 
     new
 }
+
+pub fn get_variants<'a>(input: &'a str, sfx_mode: SfxMode) -> VariantList<'a> {
+    input
+        .lines()
+        .fold(VariantList::new(), |mut state, line| {
+            if let Some(l) = line.strip_prefix("#SFXV") {
+                if let Some((first, second)) = l.trim().rsplit_once(' ') {
+                    use SfxMode::*;
+                    match sfx_mode {
+                        Off => state.all_delims.insert(first),
+                        On => state.all_delims.insert(second),
+                    };
+                }
+            } else if let Some(l) = line.strip_prefix("#VARIANT") {
+                let (first, second) = {
+                    let rest = l.trim();
+                    if let Some((f, s)) = rest.rsplit_once(' ') {
+                        (f, s)
+                    } else {
+                        (rest, "_default_")
+                    }
+                };
+
+                state.all_delims.insert(first);
+
+                if state.variants.len() == 0 && second != "_default_" {
+                    state.variants.insert(
+                        "_default_",
+                        Variant {
+                            keep_delim: first,
+                            remove_delims: HashSet::new(),
+                        },
+                    );
+                }
+                state.variants.insert(
+                    second,
+                    Variant {
+                        keep_delim: first,
+                        remove_delims: HashSet::new(),
+                    },
+                );
+            }
+
+            state
+        })
+        .finish()
+}