From 5e31eafdfb160813b566ed604cc169777d350b53 Mon Sep 17 00:00:00 2001
From: Branden J Brown <zephyrtronium@gmail.com>
Date: Thu, 17 Oct 2024 11:16:05 -0400
Subject: [PATCH] script: syntax model

---
 src/directive.rs |  4 +--
 src/main.rs      |  1 +
 src/script.rs    | 64 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 67 insertions(+), 2 deletions(-)
 create mode 100644 src/script.rs

diff --git a/src/directive.rs b/src/directive.rs
index 1097f20..99309c5 100644
--- a/src/directive.rs
+++ b/src/directive.rs
@@ -12,7 +12,7 @@ pub struct TypeSystem {
 /// The definition of a standard directive.
 ///
 /// Note that this type is an input to the parser, not an output.
-#[derive(Debug, PartialEq, Eq, Default)]
+#[derive(Debug, PartialEq, Eq, Default, Clone)]
 pub struct Directive {
     /// The provider's name for the directive.
     name: String,
@@ -39,7 +39,7 @@ pub struct Directive {
 }
 
 /// Directive parameter.
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq, Clone)]
 pub struct Param {
     /// Name to which the compiler maps the argument.
     name: String,
diff --git a/src/main.rs b/src/main.rs
index 66c7228..196895c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,5 @@
 mod directive;
+mod script;
 
 fn main() {
     println!("Hello, world!");
diff --git a/src/script.rs b/src/script.rs
new file mode 100644
index 0000000..01022bd
--- /dev/null
+++ b/src/script.rs
@@ -0,0 +1,64 @@
+use std::time;
+
+use crate::directive;
+
+/// A line of VijiN script.
+pub enum Line {
+    Spoken {
+        speaker: Vec<TextFragment>,
+        directive: Option<Vec<Directive>>,
+        speech: Vec<SpeechFragment>,
+    },
+    Directive(Vec<Directive>),
+    Comment(String),
+}
+
+/// Call to a directive.
+///
+/// Each separate directive instance is a single call, even when using the
+/// implicit prefix form. This allows the implicit prefix to still invoke a
+/// different directive, e.g. `[Enter Bocchi, Ryo stage left.]`.
+pub struct Directive {
+    target: directive::Directive,
+    prefix: Option<Arg>,
+    infix: Option<Arg>,
+    suffix: Option<Arg>,
+    list: Vec<ListArg>,
+}
+
+/// Single argument to a directive.
+pub enum Arg {
+    Text(Vec<TextFragment>),
+    Speech(Vec<SpeechFragment>),
+    Character(String),
+    Duration(time::Duration),
+    Asset(String),
+    Enumerant(String),
+}
+
+/// List argument, possibly including nuance.
+pub struct ListArg {
+    arg: Arg,
+    nuance: Option<Arg>,
+}
+
+/// Parsed fragment of text.
+pub enum TextFragment {
+    /// Literal or quoted text.
+    /// May start and end with spaces.
+    Literal(String),
+    /// Reference to a variable of the given name.
+    /// Does not include the `{}` which marks it as a variable reference.
+    Variable(String),
+}
+
+/// Parsed fragment of speech text.
+///
+/// Fragments may start or end with spaces, but they do not include the syntax
+/// used to delimit them.
+pub enum SpeechFragment {
+    Plain(Vec<TextFragment>),
+    Emphasis(Vec<TextFragment>),
+    Yell(Vec<TextFragment>),
+    Whisper(Vec<TextFragment>),
+}