Top 1,000 Features Creators Events Podcasts Extensions Blog Explorer CSV Download

Terra

< >

Terra is an open source programming language created in 2012.

#208on PLDB 12Years Old 410Repos
Download source code:
git clone https://github.com/zdevito/terra

Terra is a low-level system programming language that is embedded in and meta-programmed by the Lua programming language:


Example from the web:
-- This top-level code is plain Lua code. function printhello() -- This is a plain Lua function print("Hello, Lua!") end printhello() -- Terra is backwards compatible with C, we'll use C's io library in our example. C = terralib.includec("stdio.h") -- The keyword 'terra' introduces a new Terra function. terra hello(argc : int, argv : &rawstring) -- Here we call a C function from Terra C.printf("Hello, Terra!\n") return 0 end -- You can call Terra functions directly from Lua, they are JIT compiled -- using LLVM to create machine code hello(0,nil) -- Terra functions are first-class values in Lua, and can be introspected -- and meta-programmed using it hello:disas() --[[ output: assembly for function at address 0x60e6010 0x60e6010(+0): push rax 0x60e6011(+1): movabs rdi, 102129664 0x60e601b(+11): movabs rax, 140735712154681 0x60e6025(+21): call rax 0x60e6027(+23): xor eax, eax 0x60e6029(+25): pop rdx 0x60e602a(+26): ret ]] -- You can save Terra code as executables, object files, or shared libraries -- and link them into existing programs terralib.saveobj("helloterra",{ main = hello })
Example from hello-world:
print("Hello World")
Example from Linguist:
C = terralib.includecstring [[ #include <stdio.h> #include <stdlib.h> ]] local arraytypes = {} function Array(T) local struct ArrayImpl { data : &T; N : int; } function ArrayImpl.metamethods.__typename(self) return "Array("..tostring(T)..")" end arraytypes[ArrayImpl] = true terra ArrayImpl:init(N : int) self.data = [&T](C.malloc(N*sizeof(T))) self.N = N end terra ArrayImpl:free() C.free(self.data) end ArrayImpl.metamethods.__apply = macro(function(self,idx) return `self.data[idx] end) ArrayImpl.metamethods.__methodmissing = macro(function(methodname,selfexp,...) local args = terralib.newlist {...} local i = symbol(int) local promotedargs = args:map(function(a) if arraytypes[a:gettype()] then return `a(i) else return a end end) return quote var self = selfexp var r : ArrayImpl r:init(self.N) for [i] = 0,r.N do r.data[i] = self.data[i]:[methodname](promotedargs) end in r end end) return ArrayImpl end struct Complex { real : float; imag : float; } terra Complex:add(c : Complex) return Complex { self.real + c.real, self.imag + c.imag } end ComplexArray = Array(Complex) N = 10 terra testit() var ca : ComplexArray ca:init(N) for i = 0,N do ca(i) = Complex { i, i + 1 } end var ra = ca:add(ca) return ra end local r = testit() assert(r.N == N) for i = 0,N-1 do assert(r.data[i].real == 2*i) assert(r.data[i].imag == 2*(i+1)) end assert(tostring(Array(int)) == "Array(int32)")

Language features

Feature Supported Token Example
Strings "
"Hello world"
Print() Debugging print
Comments
-- A comment
Line Comments --
-- A comment
Semantic Indentation X

View source

- Build the next great programming language · About · Resources · Acknowledgements · Part of the World Wide Scroll