TypeInquiry

An expr node, which is used to represent the Inquiry intrinsic function whose value is computed based on the argument type.

声明

语法

TypeInquiry(int inquiry_id, ttype arg_type, expr? arg, ttype type, expr value)

参数

Argument Name	Argument Description
inquiry_id	Function unique ID
arg_type	argument type
arg	argument passed
type	output type
value	compile time value

返回值

The return value is the expression that the TypeInquiry represents.

描述

TypeInquiry is used to represent the Inquiry function. This node accepts exactly one ttype as it’s only argument (arg_type), and it returns a value depending on inquiry_id of ttype type. Since the type arg_type is known at compile time, also the compile time value is always present in value. There is an optional argument arg that specifies the variable used in the frontend language (used in LFortran, but not present in LPython/NumPy).

Here a list of inquiry_id that we support so far

Inquiry function	Output	Output type
Epsilon	smallest number E	arg_type
Huge	largest number	arg_type
Precision	decimal precision	int32
Radix	base of a numeric model	int32
Range	decimal exponent range	int32
Rank	rank of a data object	int32
Tiny	smallest positive number	arg_type

Note: All the functions output are computed based on the arg_type

类型

The arg_type and type vary for each inquiry_id signature. The output is either the default integer or the same as the argument type.

示例

The following example code creates TypeInquiry ASR node:

print *, tiny(5.0)

ASR:

(Print
    [(TypeInquiry
        Tiny
        (Real 4)
        (RealConstant
            5.000000
            (Real 4)
        )
        (Real 4)
        (RealConstant
            0.000000
            (Real 4)
        )
    )]
    ()
    ()
)

也可以看看

IntrinsicFunction