do_loop_head¶
The control of a counted loop.
Declaración¶
Sintaxis¶
do_loop_head = (expr? v, expr? start, expr? end, expr? increment)
Argumentos¶
Argument |
Descripción |
|---|---|
|
the loop variable. |
|
its first value. |
|
its last value. |
|
the step, or |
Valores devueltos¶
None.
Descripción¶
Shared by DoLoop, DoConcurrentLoop and ForAllSingle, so that one form of loop control serves all three.
The trip count is computed from start, end and increment before the
first iteration. A head whose members are all nil is an infinite loop.
Ejemplos¶
(do_loop_head
:v (Var
:v (SymbolRef 1 "i")
)
:start (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:end (IntegerConstant
:n 10
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:increment (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
)
It comes from this complete ASR text document:
(TranslationUnit
:symtab (SymbolTable
:id 0
:symbols {
"main" (Program
:symtab (SymbolTable
:id 1
:symbols {
"i" (Variable
:parent_symtab 1
:name "i"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Integer
:kind 4
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
"j" (Variable
:parent_symtab 1
:name "j"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Integer
:kind 4
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
"p" (Variable
:parent_symtab 1
:name "p"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Logical
:kind 4
)
:type_declaration nil
:abi :Source
:access :Public
:presence :Required
:value_attr false
:target_attr false
:contiguous_attr false
:bindc_name nil
:is_volatile false
:is_protected false
:pass_attr :NotMethod
:self_argument nil
:codims []
)
}
)
:name "main"
:dependencies []
:body [
(DoLoop
:name "loop"
:head (do_loop_head
:v (Var
:v (SymbolRef 1 "i")
)
:start (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:end (IntegerConstant
:n 10
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:increment (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
)
:body [
(If
:name nil
:test (IntegerCompare
:left (Var
:v (SymbolRef 1 "i")
)
:op :Eq
:right (IntegerConstant
:n 5
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Logical
:kind 4
)
:value nil
)
:body [
(Cycle
:stmt_name "loop"
)
]
:orelse []
)
(If
:name nil
:test (Var
:v (SymbolRef 1 "p")
)
:body [
(Exit
:stmt_name "loop"
)
]
:orelse [
(Assignment
:target (Var
:v (SymbolRef 1 "j")
)
:value (Var
:v (SymbolRef 1 "i")
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
]
)
]
:orelse []
)
(WhileLoop
:name nil
:test (IntegerCompare
:left (Var
:v (SymbolRef 1 "j")
)
:op :Lt
:right (IntegerConstant
:n 100
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Logical
:kind 4
)
:value nil
)
:body [
(Assignment
:target (Var
:v (SymbolRef 1 "j")
)
:value (IntegerBinOp
:left (Var
:v (SymbolRef 1 "j")
)
:op :Add
:right (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Integer
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
]
:orelse []
)
(Assert
:test (IntegerCompare
:left (Var
:v (SymbolRef 1 "j")
)
:op :GtE
:right (IntegerConstant
:n 0
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (Logical
:kind 4
)
:value nil
)
:msg (StringConstant
:s "j is not negative"
:type (String
:kind 1
:len (IntegerConstant
:n 17
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
)
)
]
)
}
)
:items []
)