String¶
A character type.
Declaration¶
Syntax¶
String(int kind, expr? len, string_length_kind len_kind,
string_physical_type physical_type)
Arguments¶
Argument |
Description |
|---|---|
|
the character kind. Kind 1, a byte, is the only one supported. |
|
the length, as an expression, or |
|
how the length is determined; see string_length_kind. |
|
how the value is represented; see StringPhysicalType. |
Return values¶
None. A type is not evaluated.
Description¶
A Fortran character value is a sequence of bytes with a length, and the four
ways of fixing that length are what len_kind distinguishes: a constant or
runtime expression (ExpressionLength), inherited from the actual argument
(AssumedLength), decided at allocation (DeferredLength), or implied by the
operation that produced the value (ImplicitLength).
physical_type is separate from all of that: it says whether the value is
carried as a descriptor or as a bare pointer, and
StringPhysicalCast is what moves
between the two without changing the logical type.
Examples¶
(String
:kind 1
:len (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
It comes from this complete ASR text document:
(TranslationUnit
:symtab (SymbolTable
:id 0
:symbols {
"main" (Program
:symtab (SymbolTable
:id 1
:symbols {
"b" (Variable
:parent_symtab 1
:name "b"
: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 []
)
"c" (Variable
:parent_symtab 1
:name "c"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (String
:kind 1
:len (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
: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 []
)
"n" (Variable
:parent_symtab 1
:name "n"
: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 []
)
"s" (Variable
:parent_symtab 1
:name "s"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (String
:kind 1
:len (IntegerConstant
:n 5
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
: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 []
)
"t" (Variable
:parent_symtab 1
:name "t"
:dependencies []
:intent :Local
:symbolic_value nil
:value nil
:storage :Default
:type (Allocatable
:type (String
:kind 1
:len nil
:len_kind :DeferredLength
:physical_type :DescriptorString
)
)
: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 [
(Assignment
:target (Var
:v (SymbolRef 1 "s")
)
:value (StringConstant
:s "hello"
:type (String
:kind 1
:len (IntegerConstant
:n 5
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "t")
)
:value (StringConcat
:left (Var
:v (SymbolRef 1 "s")
)
:right (StringConstant
:s "!"
:type (String
:kind 1
:len (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
)
:type (String
:kind 1
:len nil
:len_kind :DeferredLength
:physical_type :DescriptorString
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "t")
)
:value (StringRepeat
:left (Var
:v (SymbolRef 1 "s")
)
:right (IntegerConstant
:n 3
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (String
:kind 1
:len nil
:len_kind :DeferredLength
:physical_type :DescriptorString
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "n")
)
:value (StringLen
:arg (Var
:v (SymbolRef 1 "s")
)
:type (Integer
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "c")
)
:value (StringItem
:arg (Var
:v (SymbolRef 1 "s")
)
:idx (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (String
:kind 1
:len (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "t")
)
:value (StringSection
:arg (Var
:v (SymbolRef 1 "s")
)
:start (IntegerConstant
:n 2
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:end (IntegerConstant
:n 4
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:step (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (String
:kind 1
:len (IntegerConstant
:n 3
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "b")
)
:value (StringCompare
:left (Var
:v (SymbolRef 1 "s")
)
:op :Eq
:right (StringConstant
:s "world"
:type (String
:kind 1
:len (IntegerConstant
:n 5
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
)
:type (Logical
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "b")
)
:value (StringContains
:substr (StringConstant
:s "ell"
:type (String
:kind 1
:len (IntegerConstant
:n 3
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
)
:str (Var
:v (SymbolRef 1 "s")
)
:type (Logical
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "n")
)
:value (StringOrd
:arg (Var
:v (SymbolRef 1 "c")
)
:type (Integer
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "c")
)
:value (StringChr
:arg (IntegerConstant
:n 65
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:type (String
:kind 1
:len (IntegerConstant
:n 1
:type (Integer
:kind 4
)
:intboz_type :Decimal
)
:len_kind :ExpressionLength
:physical_type :DescriptorString
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "n")
)
:value (Ichar
:arg (Var
:v (SymbolRef 1 "c")
)
:type (Integer
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
(Assignment
:target (Var
:v (SymbolRef 1 "n")
)
:value (Iachar
:arg (Var
:v (SymbolRef 1 "c")
)
:type (Integer
:kind 4
)
:value nil
)
:overloaded nil
:realloc_lhs false
:move_allocation false
)
]
)
}
)
:items []
)
See Also¶
StringPhysicalType, string_length_kind, StringConstant, StringPhysicalCast