An environment with some Scheme standard procedures.
()
| 23 | ################ Global Environment |
| 24 | |
| 25 | def standard_env(): |
| 26 | "An environment with some Scheme standard procedures." |
| 27 | env = {} |
| 28 | env.update(vars(math)) # sin, cos, sqrt, pi, ... |
| 29 | env.update({ |
| 30 | '+':op.add, '-':op.sub, '*':op.mul, '/':op.truediv, |
| 31 | '>':op.gt, '<':op.lt, '>=':op.ge, '<=':op.le, '=':op.eq, |
| 32 | 'abs': abs, |
| 33 | 'append': op.add, |
| 34 | 'apply': lambda proc, args: proc(*args), |
| 35 | 'begin': lambda *x: x[-1], |
| 36 | 'car': lambda x: x[0], |
| 37 | 'cdr': lambda x: x[1:], |
| 38 | 'cons': lambda x,y: [x] + y, |
| 39 | 'eq?': op.is_, |
| 40 | 'equal?': op.eq, |
| 41 | 'length': len, |
| 42 | 'list': lambda *x: list(x), |
| 43 | 'list?': lambda x: isinstance(x,list), |
| 44 | 'map': lambda *args: list(map(*args)), |
| 45 | 'max': max, |
| 46 | 'min': min, |
| 47 | 'not': op.not_, |
| 48 | 'null?': lambda x: x == [], |
| 49 | 'number?': lambda x: isinstance(x, Number), |
| 50 | 'procedure?': callable, |
| 51 | 'round': round, |
| 52 | 'symbol?': lambda x: isinstance(x, Symbol), |
| 53 | }) |
| 54 | return env |
| 55 | |
| 56 | global_env = standard_env() |
| 57 |