simple_expr_parser_tables.py

import pgen_runtime
from pgen_runtime import Apply

actions = [
    # 0. <empty>
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 1. "-"
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 2. NUM
    {None: -9, '*': -9, '/': -9, '+': -9, '-': -9, ')': -9},

    # 3. VAR
    {None: -10, '*': -10, '/': -10, '+': -10, '-': -10, ')': -10},

    # 4. "("
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 5. expr
    {'+': 11, '-': 12, None: -9223372036854775807},

    # 6. term
    {'*': 13, '/': 14, None: -1, '+': -1, '-': -1, ')': -1},

    # 7. unary
    {None: -4, '*': -4, '/': -4, '+': -4, '-': -4, ')': -4},

    # 8. prim
    {None: -7, '*': -7, '/': -7, '+': -7, '-': -7, ')': -7},

    # 9. "-" unary
    {None: -8, '*': -8, '/': -8, '+': -8, '-': -8, ')': -8},

    # 10. "(" expr
    {')': 15, '+': 11, '-': 12},

    # 11. expr "+"
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 12. expr "-"
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 13. term "*"
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 14. term "/"
    {'-': 1, 'NUM': 2, 'VAR': 3, '(': 4},

    # 15. "(" expr ")"
    {None: -11, '*': -11, '/': -11, '+': -11, '-': -11, ')': -11},

    # 16. expr "+" term
    {'*': 13, '/': 14, None: -2, '+': -2, '-': -2, ')': -2},

    # 17. expr "-" term
    {'*': 13, '/': 14, None: -3, '+': -3, '-': -3, ')': -3},

    # 18. term "*" unary
    {None: -5, '*': -5, '/': -5, '+': -5, '-': -5, ')': -5},

    # 19. term "/" unary
    {None: -6, '*': -6, '/': -6, '+': -6, '-': -6, ')': -6},

]

ctns = [
    {'expr': 5, 'term': 6, 'unary': 7, 'prim': 8},
    {'unary': 9, 'prim': 8},
    {},
    {},
    {'expr': 10, 'term': 6, 'unary': 7, 'prim': 8},
    {},
    {},
    {},
    {},
    {},
    {},
    {'term': 16, 'unary': 7, 'prim': 8},
    {'term': 17, 'unary': 7, 'prim': 8},
    {'unary': 18, 'prim': 8},
    {'unary': 19, 'prim': 8},
    {},
    {},
    {},
    {},
    {},
]

reductions = [
    ('expr', 1, lambda builder, x0: builder.expr_P0(x0)),
    ('expr', 3, lambda builder, x0, x1, x2: builder.expr_P1(x0, x1, x2)),
    ('expr', 3, lambda builder, x0, x1, x2: builder.expr_P2(x0, x1, x2)),
    ('term', 1, lambda builder, x0: builder.term_P0(x0)),
    ('term', 3, lambda builder, x0, x1, x2: builder.term_P1(x0, x1, x2)),
    ('term', 3, lambda builder, x0, x1, x2: builder.term_P2(x0, x1, x2)),
    ('unary', 1, lambda builder, x0: builder.unary_P0(x0)),
    ('unary', 2, lambda builder, x0, x1: builder.unary_P1(x0, x1)),
    ('prim', 1, lambda builder, x0: builder.prim_P0(x0)),
    ('prim', 1, lambda builder, x0: builder.prim_P1(x0)),
    ('prim', 3, lambda builder, x0, x1, x2: builder.prim_P2(x0, x1, x2)),
]

class DefaultBuilder:
    def expr_P0(self, *args): return ('expr', 0, list(args))
    def expr_P1(self, *args): return ('expr', 1, list(args))
    def expr_P2(self, *args): return ('expr', 2, list(args))
    def term_P0(self, *args): return ('term', 0, list(args))
    def term_P1(self, *args): return ('term', 1, list(args))
    def term_P2(self, *args): return ('term', 2, list(args))
    def unary_P0(self, *args): return ('unary', 0, list(args))
    def unary_P1(self, *args): return ('unary', 1, list(args))
    def prim_P0(self, *args): return ('prim', 0, list(args))
    def prim_P1(self, *args): return ('prim', 1, list(args))
    def prim_P2(self, *args): return ('prim', 2, list(args))


parse_expr = pgen_runtime.make_parse_fn(actions, ctns, reductions, 0, DefaultBuilder)