From 050edf26e1df36bb60e1620a3ebc11cf3d0e6e7a Mon Sep 17 00:00:00 2001
From: David Sehnal <david.sehnal@gmail.com>
Date: Sat, 14 Oct 2017 10:57:43 +0200
Subject: [PATCH] tweaked docs
---
docs/cif-schemas.md | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/docs/cif-schemas.md b/docs/cif-schemas.md
index c464c64ad..888b58bd9 100644
--- a/docs/cif-schemas.md
+++ b/docs/cif-schemas.md
@@ -15,6 +15,12 @@ This is obviously not strongly typed + the "fields" dont know what type they are
type FieldSchema<T> = { T: T /* remember the type */, createColumn: CIFField => Column<T> }
```
+where column is just a function that for a given row returns a value of ``T``:
+
+```ts
+type Column<T> = (row: number) => T
+```
+
Category schema is just an object whose properties are all instances of "field schemas", its "shape" has the type:
```ts
@@ -25,8 +31,8 @@ We can declare our first category "schema":
```ts
const my_category = {
- num_field: { T: 0 as number, createColumn: f => Column(f => f.getNumber) }
- str_field: { T: '' as string, createColumn: f => Column(f => f.getString) }
+ num_field: { T: 0 as number, createColumn: f => f.getNumber }
+ str_field: { T: '' as string, createColumn: f => f.getString }
}
```
@@ -50,12 +56,19 @@ function toTypedCategory<Schema extends CategorySchema>(schema: Schema, category
const field = category(key);
typedCategory[key] = field
? schema[key].createFolumn(field)
- : UndefinedColumn; // a column that always returns 0 or empty string depending on type
+ : UndefinedColumn(schema[key].T); // a column that always returns 0 or empty string depending on type
}
return typedCategory;
}
```
+This transforms the ''untyped'' ``Category`` to some typed category and gives us code-completion for CIF files:
+
+```ts
+const typed = toTypedCategory(my_category, ...);
+typed.n /* shows code completion for num_field */
+```
+
And that's all there is to it. Extending the types to the "block" level is left as an exercise to the reader.
----------------
--
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