[improvement] Col: jsx (#2500)

packages/col/index.js

@@ -0,0 +1,34 @@
+import { use } from '../utils';
+
+const [sfc, bem] = use('col');
+
+export default sfc({
+  props: {
+    span: [Number, String],
+    offset: [Number, String],
+    tag: {
+      type: String,
+      default: 'div'
+    }
+  },
+
+  computed: {
+    gutter() {
+      return (this.$parent && Number(this.$parent.gutter)) || 0;
+    },
+
+    style() {
+      const padding = `${this.gutter / 2}px`;
+      return this.gutter ? { paddingLeft: padding, paddingRight: padding } : {};
+    }
+  },
+
+  render(h) {
+    const { span, offset } = this;
+    return (
+      <this.tag class={bem({ [span]: span, [`offset-${offset}`]: offset })} style={this.style}>
+        {this.$slots.default}
+      </this.tag>
+    );
+  }
+});