From ed945e4b6e21f31c81cd5548d9cb09a4b61b5ea7 Mon Sep 17 00:00:00 2001
From: Tiffany Bennett <tiffany@stormbit.net>
Date: Tue, 27 Sep 2016 10:58:17 -0400
Subject: [PATCH] Add parsing for substance definitions

---
 src/ast.rs       |  9 +++++++++
 src/gnu_units.rs | 52 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/load.rs      |  4 ++++
 3 files changed, 65 insertions(+)

diff --git a/src/ast.rs b/src/ast.rs
index af54976..91b740a 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -81,6 +81,14 @@ pub enum DatePattern {
     Space,
 }
 
+#[derive(Debug)]
+pub struct Property {
+    pub name: String,
+    pub input: Expr,
+    pub output: Expr,
+    pub doc: Option<String>,
+}
+
 #[derive(Debug)]
 pub enum Def {
     Dimension,
@@ -89,6 +97,7 @@ pub enum Def {
     SPrefix(Expr),
     Unit(Expr),
     Quantity(Expr),
+    Substance(Vec<Property>),
     Error(String),
 }
 
diff --git a/src/gnu_units.rs b/src/gnu_units.rs
index f40da9a..684ebbb 100644
--- a/src/gnu_units.rs
+++ b/src/gnu_units.rs
@@ -25,6 +25,8 @@ pub enum Token {
     Dash,
     Asterisk,
     Question,
+    LeftBrace,
+    RightBrace,
     Error(String),
 }
 
@@ -65,6 +67,8 @@ impl<'a> Iterator for TokenIterator<'a> {
             '-' => Token::Dash,
             '+' => Token::Plus,
             '*' => Token::Asterisk,
+            '{' => Token::LeftBrace,
+            '}' => Token::RightBrace,
             '?' => if self.0.peek() == Some(&'?') {
                 self.0.next();
                 let mut out = String::new();
@@ -315,6 +319,54 @@ pub fn parse(mut iter: &mut Iter) -> Defs {
                         iter.next();
                         let expr = parse_expr(iter);
                         map.push((name, Rc::new(Def::Quantity(expr)), doc.take()));
+                    } else if let Some(&Token::LeftBrace) = iter.peek() {
+                        // substance
+                        iter.next();
+                        let mut props = vec![];
+                        let mut prop_doc = None;
+                        loop {
+                            let name = match iter.next().unwrap() {
+                                Token::Ident(name) => name,
+                                Token::Newline => {
+                                    line += 1;
+                                    continue
+                                },
+                                Token::Eof => break,
+                                Token::Doc(line) => {
+                                    prop_doc = match prop_doc.take() {
+                                        None => Some(line.trim().to_owned()),
+                                        Some(old) => Some(format!(
+                                            "{} {}", old.trim(), line.trim())),
+                                    };
+                                    continue
+                                },
+                                Token::RightBrace =>
+                                    break,
+                                x => {
+                                    println!("Expected property, got {:?}", x);
+                                    break
+                                },
+                            };
+                            let input = parse_mul(iter);
+                            match iter.next().unwrap() {
+                                Token::Slash => (),
+                                x => {
+                                    println!("Expected /, got {:?}", x);
+                                    break
+                                }
+                            }
+                            let output = parse_mul(iter);
+                            props.push(Property {
+                                name: name,
+                                input: input,
+                                output: output,
+                                doc: prop_doc.take()
+                            });
+                        }
+                        map.push((
+                            name,
+                            Rc::new(Def::Substance(props)),
+                            doc.take()));
                     } else {
                         // derived
                         let expr = parse_expr(iter);
diff --git a/src/load.rs b/src/load.rs
index 7ed4933..ca5eab5 100644
--- a/src/load.rs
+++ b/src/load.rs
@@ -268,6 +268,10 @@ impl Context {
                     Ok(_) => println!("Quantity {} is not a number", name),
                     Err(e) => println!("Quantity {} is malformed: {}", name, e)
                 },
+                Def::Substance(ref props) => {
+                    println!("{:#?}", props);
+                    unimplemented!()
+                },
                 Def::Error(ref err) => println!("Def {}: {}", name, err),
             };
         }