wip: fix doctree example

lib/biz/spreadsheet/cell.v

@@ -0,0 +1,35 @@
+module spreadsheet
+
+import freeflowuniverse.herolib.data.currency
+
+pub struct Cell {
+pub mut:
+	val   f64
+	row   &Row @[skip; str: skip]
+	empty bool = true
+}
+
+pub fn (mut c Cell) set(v string) ! {
+	// means we insert a currency so need to do the exchange
+	mut amount := currency.amount_get(v)!
+	assert amount.currency.name != ''
+	mut amount2 := amount.exchange(c.row.sheet.currency)! // do the exchange to the local currency
+	c.val = amount2.val
+	c.empty = false
+}
+
+pub fn (mut c Cell) add(v f64) {
+	c.val += v
+	c.empty = false
+}
+
+pub fn (mut c Cell) repr() string {
+	if c.empty {
+		return '-'
+	}
+	return float_repr(c.val, c.row.reprtype)
+}
+
+pub fn (mut c Cell) str() string {
+	return c.repr()
+}