def buffer_lines(lines, prompt="scm> ", show_prompt=False):
    """Return a Buffer instance iterating through LINES."""
    if show_prompt:
        input_lines = lines
    else:
        input_lines = LineReader(lines, prompt)
    return Buffer(tokenize_lines(input_lines))

def run_tests(src_file = 'tests.scm'):
    """Run a read-eval loop that reads from src_file and collects outputs."""
    sys.stderr = sys.stdout = io.StringIO() # Collect output to stdout and stderr
    try:
        reader = TestReader(open(src_file).readlines())
        src = Buffer(tokenize_lines(reader))
        def next_line():
            src.current()
            return src
        read_eval_print_loop(next_line, create_global_frame())
    except BaseException as exc:
        sys.stderr = sys.__stderr__
        print("Tests terminated due to unhandled exception "
              "after line {0}:\n>>>".format(reader.line_number),
              file=sys.stderr)
        raise
    output = sys.stdout.getvalue().split('\n')
    sys.stdout = sys.__stdout__  # Revert stdout
    summarize(output, reader.expected_output)

def read_line(line):
    """Read a single string LINE as a Scheme expression."""
    return scheme_read(Buffer(tokenize_lines([line])))

def buffer_input(prompt="scm> "):
    """Return a Buffer instance containing interactive input."""
    return Buffer(tokenize_lines(InputReader(prompt)))

def buffer_lines(lines, prompt="scm> "):
    """Return a Buffer instance iterating through LINES."""
    return Buffer(tokenize_lines(LineReader(lines, prompt)))

def buffer_input(prompt="scm> "): # 从输入获取一行，然后将这一行数据传递给tokenize_lines
    # tokenize_lines处理之后，输出串token，传递个buffer，buffer可是一个可以迭代的对象，所以，你懂的!
    """Return a Buffer instance containing interactive input."""
    return Buffer(tokenize_lines(InputReader(prompt)))

def buffer_input():
    return Buffer(tokenize_lines(InputReader('> ')))

from scheme_reader import *
from buffer import Buffer, InputReader, LineReader
from scheme_tokens import tokenize_lines, DELIMITERS 

lines = ["(+ 1 ", "(+ 23 4)) ("]
src = Buffer(tokenize_lines(lines))
print(scheme_read(src))
print(repr(read_line("'hello")))
print(read_line("(car '(1 2))"))

print(repr(read_tail(Buffer(tokenize_lines([")"])))))
print(repr(read_tail(Buffer(tokenize_lines(["2 3)"])))))
print(repr(read_tail(Buffer(tokenize_lines(["2 (3 4))"])))))
print(repr(read_line("(1 . 2)")))
print(repr(read_line("(1 2 . 3)")))
print(repr(read_line("(1 . 2 3)")))
print(repr(scheme_read(Buffer(tokenize_lines(["(1", "2 .", "'(3 4))", "4"])))))

def scheme_repl(source, prompt, env, print_input=True):
    """Start a read-eval-print loop reading from SOURCE."""
    read_eval_print(Buffer(tokenize_lines(source)), prompt, env, print_input)