variable assignments

1 files changed, 30 insertions, 5 deletions

diff --git a/src/parse.rs b/src/parse.rs
index 2902633..cbc37bf 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -27,14 +27,14 @@ pub trait Expander {
 
 #[derive(Debug, Clone)]
 pub enum Ast<T: Stage> {
-    AssignVar(AssignVar),
+    VarAssign(VarAssign),
     Pipes(Pipes<T>),
 }
 
 impl Ast<PreExpansion> {
     pub fn expand<E: Expander>(self, e: &mut E) -> Res<Ast<PostExpansion>, E::Error> {
         match self {
-            Ast::AssignVar(_) => todo!(),
+            Ast::VarAssign(_) => todo!(),
             Ast::Pipes(pipes) => Ok(Ast::Pipes(pipes.expand(e)?)),
         }
     }
@@ -100,9 +100,32 @@ pub struct VarDecl<S: Stage> {
 }
 
 #[derive(Debug, Clone)]
-pub struct AssignVar {
-    pub to: String,
-    // TODO: body
+pub struct VarAssign<S: Stage> {
+    pub var: S::Str,
+    pub val: S::Str,
+}
+
+impl Parse for VarAssign<PreExpansion> {
+    fn parse(b: &mut Cursor<'_>) -> Result<Self> {
+        if !b.buf.starts_with(b"set ") && !b.buf.starts_with(b"set\t") {
+            return Err(ParseError::NotAVarAssign);
+        }
+        b.advance(4);
+        b.spaces();
+        let var = ExpString::parse(b)?;
+        b.spaces();
+
+        if b.is_empty() {
+            return Err(ParseError::Eof);
+        }
+        let eq = b.adv();
+        if eq != b'=' {
+            return Err(ParseError::Expected('='));
+        }
+        let val = ExpString::parse(b)?;
+
+        Ok(Self { var, val })
+    }
 }
 
 #[derive(Debug, Clone)]
@@ -364,6 +387,8 @@ pub enum ParseError {
     NotAString,
 
     NotAFunDecl,
+
+    NotAVarAssign,
 }
 
 type Result<T> = std::result::Result<T, ParseError>;