directive: parse and type check definitions

Cargo.lock

@@ -23,6 +23,12 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "itoa"
 version = "1.0.11"
@@ -168,6 +174,27 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "snafu"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "223891c85e2a29c3fe8fb900c1fae5e69c2e42415e3177752e8718475efa5019"
+dependencies = [
+ "snafu-derive",
+]
+
+[[package]]
+name = "snafu-derive"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "03c3c6b7927ffe7ecaa769ee0e3994da3b8cafc8f444578982c83ecb161af917"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "syn"
 version = "2.0.79"
@@ -192,4 +219,5 @@ dependencies = [
  "rstest",
  "serde",
  "serde_json",
+ "snafu",
 ]

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [dependencies]
 serde = { version = "1.0.210", features = ["derive"] }
 serde_json = "1.0.128"
+snafu = "0.8.5"
 
 [dev-dependencies]
 rstest = { version = "0.23.0", default-features = false }

src/directive.rs

@@ -1,3 +1,13 @@
+use std::collections::BTreeMap;
+
+use snafu::{ResultExt, Snafu};
+
+/// The types and directives in a VijiN project.
+pub struct TypeSystem {
+    pub types: BTreeMap<String, Type>,
+    pub directives: BTreeMap<String, Directive>,
+}
+
 /// The definition of a standard directive.
 ///
 /// Note that this type is an input to the parser, not an output.
@@ -39,6 +49,7 @@ pub struct Param {
 }
 
 /// Types expected by directive arguments.
+#[derive(Clone)]
 pub enum Type {
     /// Arbitrary text.
     Text,
@@ -60,14 +71,14 @@ mod serial {
 
     #[derive(Deserialize)]
     #[serde(rename_all = "snake_case", deny_unknown_fields)]
-    struct Document {
+    pub struct Document {
-        types: Vec<Type>,
+        pub types: Vec<Type>,
-        directives: Vec<Directive>,
+        pub directives: Vec<Directive>,
     }
 
     #[derive(Deserialize)]
     #[serde(rename_all = "snake_case", deny_unknown_fields, tag = "kind")]
-    enum TypeKind {
+    pub enum TypeKind {
         Text,
         Speech,
         Character,
@@ -83,39 +94,172 @@ mod serial {
 
     #[derive(Deserialize)]
     #[serde(rename_all = "snake_case", deny_unknown_fields)]
-    struct Type {
+    pub struct Type {
-        name: String,
+        pub name: String,
-        doc: String,
+        pub doc: String,
-        kind: TypeKind,
+        pub kind: TypeKind,
     }
 
     #[derive(Deserialize)]
     #[serde(rename_all = "snake_case", deny_unknown_fields)]
-    struct Param {
+    pub struct Param {
-        name: String,
+        pub name: String,
-        doc: Option<String>,
+        pub doc: Option<String>,
         #[serde(rename = "type")]
-        typ: String,
+        pub typ: String,
-        nuance: Option<Box<Param>>,
+        pub nuance: Option<Box<Param>>,
     }
 
     #[derive(Deserialize)]
     #[serde(rename_all = "snake_case", deny_unknown_fields)]
-    struct Directive {
+    pub struct Directive {
-        name: String,
+        pub name: String,
-        doc: String,
+        pub doc: Option<String>,
-        prefix: String,
+        pub prefix: String,
-        prefix_param: Option<Param>,
+        pub prefix_param: Option<Param>,
-        infix: Option<String>,
+        pub infix: Option<String>,
-        infix_param: Option<Param>,
+        pub infix_param: Option<Param>,
-        suffix: Option<String>,
+        pub suffix: Option<String>,
-        suffix_param: Option<Param>,
+        pub suffix_param: Option<Param>,
-        list_param: Option<Param>,
+        pub list_param: Option<Param>,
     }
 }
 
+#[derive(Debug, Snafu)]
+pub enum Error {
+    #[snafu(display("invalid directive definition file: {source}"))]
+    Decode { source: serde_json::Error },
+
+    #[snafu(display("no type {name} of {position} parameter for {directive}"))]
+    ParamType {
+        directive: String,
+        position: &'static str,
+        name: String,
+    },
+
+    #[snafu(display("{directive} has {position} parameter with no {position}"))]
+    MissingSyntax {
+        directive: String,
+        position: &'static str,
+    },
+
+    #[snafu(display("{directive} has illegal nuance on {position}"))]
+    InvalidNuance {
+        directive: String,
+        position: &'static str,
+    },
+}
+
 static DIRECTIVE_PREDECLARED: &str = include_str!("directive-predeclared.json");
 
+impl TypeSystem {
+    pub fn new() -> TypeSystem {
+        let mut ts = TypeSystem {
+            types: BTreeMap::new(),
+            directives: BTreeMap::new(),
+        };
+        ts.parse(DIRECTIVE_PREDECLARED).unwrap();
+        ts
+    }
+
+    pub fn parse(&mut self, src: &str) -> Result<&mut Self, Error> {
+        let s: serial::Document = serde_json::from_str(src).context(DecodeSnafu)?;
+        for t in s.types {
+            let p = match t.kind {
+                serial::TypeKind::Text => Type::Text,
+                serial::TypeKind::Speech => Type::Speech,
+                serial::TypeKind::Character => Type::Character,
+                serial::TypeKind::Duration => Type::Duration,
+                serial::TypeKind::Asset { tags } => Type::Asset { tags },
+                serial::TypeKind::Enum { enm } => Type::Enum(enm),
+            };
+            self.types.insert(t.name, p);
+        }
+        for d in s.directives {
+            let prefix_param = d
+                .prefix_param
+                .map(|p| self.param(&d.name, "prefix", p))
+                .transpose()?;
+            let infix_param = d
+                .infix_param
+                .map(|p| {
+                    if d.suffix.is_none() {
+                        return Err(Error::MissingSyntax {
+                            directive: d.name.clone(),
+                            position: "infix",
+                        });
+                    }
+                    self.param(&d.name, "infix", p)
+                })
+                .transpose()?;
+            let suffix_param = d
+                .suffix_param
+                .map(|p| {
+                    if d.suffix.is_none() {
+                        return Err(Error::MissingSyntax {
+                            directive: d.name.clone(),
+                            position: "suffix",
+                        });
+                    }
+                    self.param(&d.name, "suffix", p)
+                })
+                .transpose()?;
+            let list_param = d
+                .list_param
+                .map(|p| self.param(&d.name, "list", p))
+                .transpose()?;
+            let r = Directive {
+                name: d.name.clone(),
+                doc: d.doc.unwrap_or_default(),
+                prefix: d.prefix,
+                prefix_param,
+                infix: d.infix,
+                infix_param,
+                suffix: d.suffix,
+                suffix_param,
+                list_param,
+            };
+            self.directives.insert(d.name, r);
+        }
+        Ok(self)
+    }
+
+    fn param(
+        &self,
+        directive: &str,
+        position: &'static str,
+        p: serial::Param,
+    ) -> Result<Param, Error> {
+        let t = match self.types.get(&p.typ) {
+            None => {
+                return Err(Error::ParamType {
+                    directive: directive.into(),
+                    position,
+                    name: p.typ,
+                })
+            }
+            Some(t) => t,
+        };
+        let nuance = if let Some(n) = p.nuance {
+            if position != "list" {
+                return Err(Error::InvalidNuance {
+                    directive: directive.into(),
+                    position,
+                });
+            }
+            Some(Box::new(self.param(directive, "list nuance", *n)?))
+        } else {
+            None
+        };
+        Ok(Param {
+            name: p.name,
+            doc: p.doc,
+            typ: t.clone(),
+            nuance,
+        })
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;