def plus_exp(node):
(PLUS,c1,c2) = node
t1 = walk(c1)
t2 = walk(c2)
return promote(t1,t2)
def mul_exp(node):
(MUL, c1, c2) = node
(t1, v1) = walk(c1)
(t2, v2) = walk(c2)
t = promote(t1, t2)
return (t, coerce(t, t1)(v1) * coerce(t, t2)(v2))
def minus_exp(node):
(MINUS, c1, c2) = node
(t1, v1) = walk(c1)
(t2, v2) = walk(c2)
t = promote(t1, t2)
return (t, coerce(t, t1)(v1) - coerce(t, t2)(v2))
def plus_exp(node):
(PLUS, c1, c2) = node
(t1, v1) = walk(c1)
(t2, v2) = walk(c2)
t = promote(t1, t2)
return (t, coerce(t, t1)(v1) + coerce(t, t2)(v2))
def le_exp(node):
(LE,c1,c2) = node
t1 = walk(c1)
t2 = walk(c2)
if promote(t1,t2)[0] == 'VOID_TYPE':
raise ValueError("Illegal type in relational operator.")
return ('INTEGER_TYPE',)
def div_exp(node):
(DIV,c1,c2) = node
t1 = walk(c1)
t2 = walk(c2)
tr = promote(t1,t2)
if tr[0] not in ['INTEGER_TYPE','FLOAT_TYPE']:
raise ValueError("operation on type {} not supported"
.format(tr[0]))
return tr
def le_exp(node):
(LE, c1, c2) = node
(t1, v1) = walk(c1)
(t2, v2) = walk(c2)
t = promote(t1, t2)
if coerce(t, t1)(v1) <= coerce(t, t2)(v2):
return ('INTEGER_TYPE', 1)
else:
return ('INTEGER_TYPE', 0)
def div_exp(node):
(DIV, c1, c2) = node
(t1, v1) = walk(c1)
(t2, v2) = walk(c2)
t = promote(t1, t2)
if t == 'INTEGER_TYPE':
return ('INTEGER_TYPE', v1 // v2)
else:
return (t, coerce(t, t1)(v1) / coerce(t, t2)(v2))