tup build system

class: center, middle

# tup Build System

---
# Why not make?

> I think automated file-level dependency detection is a baseline requirement for build systems.
> Even if it is possible for a human to correctly list the dependencies for a single build,
> it really isn't possible to maintain as files are added/deleted/moved around.
>
> **Mike Shal**

<br />
> Rules are easy.<br />
> Dependencies are hard.
>
> **Dwight Shih**

<br />
[tup](http://gittup.org/tup/) automatically determines file based dependencies
by using a FUSE filesystem to track reads and writes. Available for Linux, OS
X and Microsoft Windows.

---
# Anatomy of a Rule
```
: [foreach] inputs [|order inputs] |> command |> outputs [|extra outputs] [<group>] [{bin}]
```

- order inputs are files/groups generated by other rules, used to control order of rule execution
- group aggregates output from multiple rules to be used as an order input
- bin aggregates output from multiple rules to be used as inputs to a rule.

---
# Example Tupfile
```
: foreach *.csv |> java -jar saxon9he.jar process_csv.xsl process_csv.xsl input="%f" > %o |> %B.xml
: foreach *.xml |> java -jar saxon9he.jar "%f" transform.xsl > "%o" |> %B.html
.gitignore

%f  filename from inputs
%b  like %f, but without directory information
%B  like %f, but without file extension
%e  input filename extension
%o  output file(s)
%O  like %o, but without file extension
%g  string that a glob (*) matched

foreach wildcards apply to filename only - not directories
```

---
# Demo

* Stores information in SQLite database in .tup directory
* Regenerates on dependency change
* Regenerates on PATH change

---
# Dependency Graph
```
tup graph . | dot -Tpng > dependency.png
```