feat: start to render some AST nodes

editor/src/lang/expr.rs

@@ -16,6 +16,10 @@ use roc_module::low_level::LowLevel;
 use roc_module::operator::CalledVia;
 use roc_module::symbol::{IdentIds, ModuleId, ModuleIds, Symbol};
 use roc_parse::ast::StrLiteral;
+use roc_parse::ast::{self, Attempting};
+use roc_parse::blankspace::space0_before;
+use roc_parse::expr::expr;
+use roc_parse::parser::{loc, Fail, Parser, State};
 use roc_problem::can::{Problem, RuntimeError};
 use roc_region::all::{Located, Region};
 use roc_types::subs::{VarStore, Variable};
@@ -222,6 +226,23 @@ pub fn to_expr_id<'a>(
     (env.add(expr, region), output)
 }
 
+pub fn str_to_expr2<'a>(
+    arena: &'a Bump,
+    input: &'a str,
+    env: &mut Env<'a>,
+    scope: &mut Scope,
+    region: Region,
+) -> Result<(Expr2, self::Output), Fail> {
+    let state = State::new(input.trim().as_bytes(), Attempting::Module);
+    let parser = space0_before(loc(expr(0)), 0);
+    let answer = parser.parse(&arena, state);
+
+    answer
+        .map(|(loc_expr, _)| loc_expr)
+        .map(|loc_expr| to_expr2(env, scope, &loc_expr.value, region))
+        .map_err(|(fail, _)| fail)
+}
+
 pub fn to_expr2<'a>(
     env: &mut Env<'a>,
     scope: &mut Scope,

editor/src/lang/mod.rs

@@ -3,7 +3,7 @@ mod def;
 mod expr;
 mod module;
 mod pattern;
-mod pool;
+pub mod pool;
 pub mod roc_file;
 mod scope;
 mod types;

editor/src/lib.rs

@@ -266,6 +266,8 @@ fn run_event_loop(file_path_opt: Option<&Path>) -> Result<(), Box<dyn Error>> {
                     );
                 } else {
                     queue_no_file_text(&size, NOTHING_OPENED, CODE_TXT_XY.into(), &mut glyph_brush);
+                    let ast = crate::lang::expr::str_to_expr2();
+                    render_node(&size, ast, CODE_TXT_XY.into(), &mut glyph_brush);
                 }
 
                 match draw_all_rects(
@@ -364,6 +366,39 @@ fn begin_render_pass<'a>(
     })
 }
 
+fn render_node(
+    size: &PhysicalSize<u32>,
+    ast: Expr2,
+    position: Vector2<f32>,
+    glyph_brush: &mut GlyphBrush<()>,
+) {
+    use Expr2::*;
+
+    let area_bounds = (size.width as f32, size.height as f32).into();
+
+    match ast {
+        SmallInt {
+            number,
+            ..
+            // text,
+            // style, pretending always decimal for now
+            // var,
+        } => {
+            let code_text = Text {
+                position,
+                area_bounds,
+                color: CODE_COLOR.into(),
+                text: number.into(),
+                size: CODE_FONT_SIZE,
+                ..Default::default()
+            };
+
+            queue_code_text_draw(&code_text, glyph_brush);
+        }
+        _ => 
+    };
+}
+
 // returns bounding boxes for every glyph
 fn queue_editor_text(
     size: &PhysicalSize<u32>,