Moved parser to typescript

app/imports/parser/parseTree/constant.ts

@@ -0,0 +1,42 @@
+import NodeFactory from '/imports/parser/parseTree/NodeFactory';
+import { Context, ResolvedResult } from '/imports/parser/resolve';
+
+type ConstantValueType = number | string | boolean | undefined
+
+export type ConstantNode = {
+  parseType: 'constant';
+  value: ConstantValueType;
+  // TODO replace all `constantNode.valueType` with `typeof constantNode.value`
+  valueType: 'number' | 'string' | 'boolean' | 'undefined';
+}
+
+interface ConstantFactory extends NodeFactory {
+  create({ value }: { value: ConstantValueType }): ConstantNode;
+  compile(
+    node: ConstantNode, scope: Record<string, any>, context: Context
+  ): ResolvedResult;
+  roll?: undefined;
+  reduce?: undefined;
+  resolve?: undefined;
+  toString(node: ConstantNode): string;
+  traverse?: undefined;
+  map?: undefined;
+}
+
+const constant: ConstantFactory = {
+  create({ value }): ConstantNode {
+    return {
+      parseType: 'constant',
+      valueType: typeof value as 'number' | 'string' | 'boolean' | 'undefined',
+      value,
+    }
+  },
+  compile(node, scope, context) {
+    return { result: node, context };
+  },
+  toString(node) {
+    return `${node.value}`;
+  },
+}
+
+export default constant;