DoLoop¶
The DO statement to repeatedly execute a set of statements.
声明¶
语法¶
DoLoop(do_loop_head head, stmt* body)
参数¶
head contains do loop header or loop control.
body contains do loop statements.
返回值¶
无。
描述¶
DoLoop statement nodes repeatedly executes a set of statements.
A labeled DO loop consists of the following:
DOstatementSet of executable statements i.e., body of the
doloopTerminal statement, like
CONTINUEstatement
The DO variable must not be modified in any way within the range of the DO
loop.
Control must not jump into the range of a DO loop from outside its range.
After the terminal statement of a DO loop is executed, the following steps are
performned:
The value of the
DOvariable, if any, is incremented.The iteration count of the loop statement is decremented by one.
The iteration count of condition is tested.
类型¶
Accessible global identifier and a sequence of zero or more statements or
construst that make the DO range.
示例¶
program doloop
implicit none
integer :: i, j
j = 0
do i = 1, 10
if (i == 2) cycle
j = j + i
end do
if (j /= 53) error stop
print *, j
end program
ASR:
(TranslationUnit
(SymbolTable
1
{
doloop_03:
(Program
(SymbolTable
2
{
i:
(Variable
2
i
Local
()
()
Default
(Integer 4 [])
Source
Public
Required
.false.
),
j:
(Variable
2
j
Local
()
()
Default
(Integer 4 [])
Source
Public
Required
.false.
)
})
doloop_03
[]
[(=
(Var 2 j)
(IntegerConstant 0 (Integer 4 []))
()
)
(DoLoop
((Var 2 i)
(IntegerConstant 1 (Integer 4 []))
(IntegerConstant 10 (Integer 4 []))
())
[(If
(IntegerCompare
(Var 2 i)
Eq
(IntegerConstant 2 (Integer 4 []))
(Logical 4 [])
()
)
[(Cycle)]
[]
)
(=
(Var 2 j)
(IntegerBinOp
(Var 2 j)
Add
(Var 2 i)
(Integer 4 [])
()
)
()
)]
)
(If
(IntegerCompare
(Var 2 j)
NotEq
(IntegerConstant 53 (Integer 4 []))
(Logical 4 [])
()
)
[(ErrorStop
()
)]
[]
)
(Print
()
[(Var 2 j)]
()
()
)]
)
})
[]
)