From 6656b90717f2a8e5249f57e8c71e5fcb1c60f20c Mon Sep 17 00:00:00 2001
From: Dustin Swan <dustin@dustinswan.com>
Date: Wed, 1 Apr 2026 16:00:11 -0600
Subject: [PATCH] Fixing multi argument Constructors. Adding a layout system!
 Flex and fixed within a column

---
 src/cg/03-ui-components.cg | 46 ++++++++++++++++++++++++++++++++++++++
 src/compiler.ts            | 25 ++++++++++++++++-----
 2 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/src/cg/03-ui-components.cg b/src/cg/03-ui-components.cg
index d91ce72..e35af10 100644
--- a/src/cg/03-ui-components.cg
+++ b/src/cg/03-ui-components.cg
@@ -379,3 +379,49 @@ measureText = config \
     width = strLen * charW * c.scale + max 0 (strLen - 1) * gap,
     height = 12 * c.scale
   };
+
+# new CG layout
+LayoutChild = Fixed Int (Int\ Int \ UI) | Flex Int (Int \ Int \ UI);
+
+layout = constraints children \
+  # Pass 1: sum fixed heights, total flex weight
+  info = fold (acc child \ child
+    | Fixed h _ \ acc.{ fixedH = acc.fixedH + h }
+    | Flex n _ \ acc.{ totalFlex = acc.totalFlex + n }
+   ) { fixedH = 0, totalFlex = 0 } children;
+
+   remainingH = constraints.h - info.fixedH;
+
+   # Pass 2
+   fold (acc child \
+     allocated = (child
+      | Fixed h view \ { h = h, view = view }
+      | Flex n view \ { h = remainingH * n / info.totalFlex, view = view });
+
+     rendered = ui.positioned {
+       x = 0,
+       y = acc.y,
+       child = allocated.view constraints.w allocated.h
+     };
+
+    acc.{ y = acc.y + allocated.h, children = [...acc.children, rendered] }
+  ) { y = 0, children = [] } children
+  ~ (r \ r.children)
+  ~ (c \ ui.stack { children = c });
+
+testApp = name \
+  { view = ctx \
+    # ui.rect { w = 10, h = 10 },
+    layout { w = ctx.w, h = ctx.h } [
+      Fixed 40 (w h \ box { w = w, h = h, color = "red", child = text "Header" }),
+      Flex 1 (w h \ box { w = w, h = h, color = "#1a1a2e", child = text "Main content" }),
+      Fixed 30 (w h \ box { w = w, h = h, color = "blue", child = text "Footer" }),
+    ]
+  };
+
+testApp2 = ctx \
+  layout { w = ctx.w, h = ctx.h } [
+    Fixed 40 (w h \ box { w = w, h = h, color = "red", child = text "Header" }),
+    Flex 1 (w h \ box { w = w, h = h, color = "#1a1a2e", child = text "Main content" }),
+    Fixed 30 (w h \ box { w = w, h = h, color = "blue", child = text "Footer" }),
+  ];
diff --git a/src/compiler.ts b/src/compiler.ts
index 2c3918f..66bbed6 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -43,13 +43,28 @@ export function compile(ast: AST, ctx: CompileCtx = defaultCtx): string {
         }
 
         case 'apply':
-            // Constructor
-            if (ast.func.kind === 'constructor') {
-                const ctorName = ast.func.name;
-                const arg = compile(ast.args[0], ctx);
-                return `({ _tag: "${ctorName}", _0: ${arg} })`;
+            // Collect constructor args from nested applie
+            let node: AST = ast;
+            const ctorArgs: AST[] = [];
+            while (node.kind === 'apply' && node.func.kind !== 'constructor') {
+                // Check if inner func is a constructor chain
+                if (node.func.kind === 'apply') {
+                    ctorArgs.unshift(node.args[0]);
+                    node = node.func;
+                } else {
+                    break;
+                }
             }
 
+            // Constructor
+            if (node.kind === 'apply' && node.func.kind === 'constructor') {
+                ctorArgs.unshift(node.args[0]);
+                const ctorName = node.func.name;
+                const compiledArgs = ctorArgs.map((a, i) => `_${i}: ${compile(a, ctx)}`).join(', ');
+                return `({ _tag: "${ctorName}", ${compiledArgs} })`;
+            }
+
+            // Function application
             const args = ast.args.map(a => compile(a, ctx)).join(')(');
             return `${compile(ast.func, ctx)}(${args})`;