I've created this repo to document my process of learning how to design a simple programming language and implemening a source-to-source compiler. I'll be taking an incremental approach, starting with a small subset of the language and ending each iteration with a working program.
I like writing bash scripts, but the syntax really puts me off. So for this exercise I'm designing a pythonic command language that compiles to bash. I'll call it Calango. Here is a sample of Calango:
for n in [1 .. 4]:
res= ps(a) | grep(-i n) | head(-1)
echo(res)
- [1 .. 4] is a range of numbers from 1 to 4.
- ps, grep, head and echo are of course shell commands. The brackets are used for passing any number of arguments to these commands.
- "|" is your usual pipeline symbol.
- Whitespace is used to denote blocks, exactly as in python. However, Calango restricts it to tabs.
Here's the bash code our compiler should output:
for i in {1..4}
do
res= ps a | grep -i $n | head
echo $res
done We'll start with a simple subset of Calango:
echo([1 .. 4])
echo(1-1+4)
for which our compiler would output:
echo {1..4}
echo $((1-1+4)) which should output:
1 2 3 4
4
The first step is to build a program that reads Calango code returns lists of the tokens found in it, along with their kinds