Beginnings of loops

src/emitter.rs

@@ -107,6 +107,7 @@ pub fn emit(w: &mut dyn Write, stmt: &parser::Stmt, ctx: &mut LexicalContext) ->
 		writeln!(w, "}}")?;
 	    }
 	}
+	parser::Stmt::Loop(_) => todo!()
     }
     Ok(())
 }

src/internal.rs

@@ -0,0 +1,3 @@
+//! Internal compiler steps, expansion, cps, optimization.
+
+

src/main.rs

@@ -1,6 +1,7 @@
 mod parser;
 mod evaluator;
 mod emitter;
+mod internal;
 
 use clap::Parser;
 

src/parser.rs

@@ -5,6 +5,7 @@ pub enum Stmt {
     Assignment(String, Expr),
     Funcall(Expr),
     Conditional(Vec<GuardedBlock>, Option<Block>),
+    Loop(Loop),
     BareExpr(Expr),
 }
 
@@ -49,6 +50,13 @@ pub struct GuardedBlock {
     pub block: Block,
 }
 
+#[derive(Debug,PartialEq,Clone)]
+pub enum Loop {
+    Bare(Block),
+    Until(GuardedBlock),
+    Over(String, Expr, Block),
+}
+
 peg::parser! {
     grammar deelang_parser() for str {
         pub rule program() -> Vec<Stmt>
@@ -57,6 +65,7 @@ peg::parser! {
             = a:assignment() { a } /
             f:funcall() stop() { Stmt::Funcall(f) } /
             c:conditional() { c } /
+	    l:_loop() { Stmt::Loop(l) } / 
             e:expr() stop() { Stmt::BareExpr(e) }
         rule expr() -> Expr = precedence! {
 	    e1:(@) "=" _ e2:@ { Expr::Equal(Box::new(e1), Box::new(e2)) }
@@ -114,6 +123,17 @@ peg::parser! {
             }
         rule _else() -> Block
             = "else" _ b:block() { b }
+	rule _loop() -> Loop
+	    = "loop" _ "until" _ e:expr() b:block() __* {
+		Loop::Until(GuardedBlock{
+		    guard:e,
+		    block: b,
+		})
+	    } /
+	    "loop" _ "over" _ i:id() "in" _ e:expr() b:block() __* {
+		Loop::Over(i, e, b)
+	    } /
+	    "loop" _ b:block() __* { Loop::Bare(b) }
         rule block() -> Block
             = i:indented_block() { i } /
 	    e:expr() { vec![Stmt::BareExpr(e)] }