Notes on software and the ideas behind it

Find the meaning
behind the code.

I’m Fred Yang. I write about software—how it works, why it behaves the way it does, and the ideas that make code easier to reason about.

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Working notes / 2026

Recently mapped

Architecture, reactivity, and the hidden relationships that shape frontend systems.

Software Design

Value object and Persistance

It is confusing to mixed value object with its persistence. We know value has has no identity. How about primary key in database. Every table in database has an primary key. Isn't that key...
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clr

What is the cost of catching an exception

We all known that following an exception without using it is quite silly. How does it really hurt performance. It turns out that difference is very small.
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asp.net mvc

The order of route is important in asp.net mvc

I have try to add route to reroute the default.aspx to home handler.
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xslt

XSLT note - xsl:output method

There are 3 method option in xsl:output element, xml, html, text. only xml option will output xml declaration. only text will disables output escaping. In your style sheet, you want to export < ,...
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xslt

XSLT note 6 - fast search node

We can make search much faster if we generate index. We generate index by using xsl:key.
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