def LeftIndex(p, w, left, unused_bp):
# type: (TdopParser, word_t, arith_expr_t, int) -> arith_expr_t
"""Array indexing, in both LValue and RValue context.
LValue: f[0] = 1 f[x+1] = 2
RValue: a = f[0] b = f[x+1]
On RHS, you can have:
1. a = f[0]
2. a = f(x, y)[0]
3. a = f[0][0] # in theory, if we want character indexing?
NOTE: a = f[0].charAt() is probably better
On LHS, you can only have:
1. a[0] = 1
Nothing else is valid:
2. function calls return COPIES. They need a name, at least in osh.
3. strings don't have mutable characters.
"""
if not tdop.IsIndexable(left):
p_die("The [ operarator doesn't apply to this expression", word=w)
index = p.ParseUntil(0)
p.Eat(Id.Arith_RBracket)
return arith_expr.Binary(word_.ArithId(w), left, index)
def LeftBinaryOp(p, w, left, rbp):
# type: (TdopParser, word_t, arith_expr_t, int) -> arith_expr_t
""" Normal binary operator like 1+2 or 2*3, etc. """
# TODO: w shoudl be a Token, and we should extract the token from it.
return arith_expr.Binary(word_.ArithId(w), left, p.ParseUntil(rbp))