Compiler = ref object
  css*: string
  program: Program
  sourceMap: SourceInfo
  minify: bool
  warnings*: seq[Warning]

Warning = tuple[msg: string, line, col: int]

proc getCSS(c: Compiler): string {....raises: [], tags: [].}

proc newCompiler(p: Program; outputPath: string; minify = false): Compiler {.
    ...raises: [KeyError, Exception], tags: [RootEffect].}

proc newCompilerStr(p: Program; outputPath: string): string {.
    ...raises: [KeyError, Exception], tags: [RootEffect].}