Reflection¶

Usage

use Reflection;

or

import Reflection;

Support for reflecting about properties of a Chapel program’s code.

Functions for reflecting about language elements, such as fields, functions, and methods.

Note

There are several ways in which this module could be improved:

the methods here might be better as type methods, so you could use R.numFields() instead of numFields(R).

getField does not yet return a mutable value.

Note

For reflecting about aspects of the compilation process, see ChplConfig.

proc numFields(type t) param: int¶: Return the number of fields in a class or record as a param. The count of fields includes types and param fields.

proc getFieldName(type t, param idx: int) param: string¶

Get the name of the field at idx in a class or record. Causes a compilation error if idx is not in 0..<numFields(t).

Arguments

t – a class or record type
idx – which field to get the name of

Returns

the name of the field, as a param string

proc getFieldName(type t, param i: int) param: string

Get the name of the field at i in a class or record. Causes a compilation error if i is not in 0..<numFields(t).

Arguments

t – a class or record type
i – which field to get the name of

Returns

the name of the field, as a param string

Warning

Formal ‘i’ is deprecated, please use ‘idx’ instead

proc getField(const ref obj: ?t, param idx: int) param¶

Get the field at idx in a class or record. When the field at idx is a param, this overload will be chosen to return a param. Causes a compilation error if idx is not in 0..<numFields(t).

Arguments

obj – a class or record
idx – which field to get

Returns

the param that field represents

proc getField(const ref x: ?t, param i: int) param

Get the ith field in a class or record. When the ith field is a param, this overload will be chosen to return a param. Causes a compilation error if i is not in 0..<numFields(t).

Arguments

x – a class or record
i – which field to get

Returns

the param that field represents

Warning

The formals ‘x’ and ‘i’ are deprecated, please use ‘obj’ and ‘idx’ instead

proc getField(const ref obj: ?t, param idx: int) type

Get the field at idx in a class or record. When the field at idx is a type variable, this overload will be chosen to return a type. Causes a compilation error if idx is not in 0..<numFields(t).

Arguments

obj – a class or record
idx – which field to get

Returns

the type that field represents

proc getField(const ref x: ?t, param i: int) type

Get the ith field in a class or record. When the ith field is a type variable, this overload will be chosen to return a type. Causes a compilation error if i is not in 0..<numFields(t).

Arguments

x – a class or record
i – which field to get

Returns

the type that field represents

Warning

The formals ‘x’ and ‘i’ are deprecated, please use ‘obj’ and ‘idx’ instead

proc getField(const ref obj: ?t, param idx: int) const ref

Get the field at idx in a class or record. Causes a compilation error if idx is not in 0..<numFields(t).

Arguments

obj – a class or record
idx – which field to get

Returns

an rvalue referring to that field.

proc getField(const ref x: ?t, param i: int) const ref

Get the ith field in a class or record. Causes a compilation error if i is not in 0..<numFields(t).

Arguments

x – a class or record
i – which field to get

Returns

an rvalue referring to that field.

Warning

The formals ‘x’ and ‘i’ are deprecated, please use ‘obj’ and ‘idx’ instead

proc getField(const ref obj: ?t, param name: string) param

Get a field in a class or record by name. When the named field is a param, this overload will be chosen to return a param. Will generate a compilation error if a field named name is not found.

Arguments

obj – a class or record
name – the name of a field

Returns

the param that field represents

proc getField(const ref x: ?t, param s: string) param

Get a field in a class or record by name. When the named field is a param, this overload will be chosen to return a param. Will generate a compilation error if a field with that name is not found.

Arguments

x – a class or record
s – the name of a field

Returns

the param that field represents

Warning

The formals ‘x’ and ‘s’ are deprecated, please use ‘obj’ and ‘name’ instead

proc getField(const ref obj: ?t, param name: string) type

Get a field in a class or record by name. When the named field is a type variable, this overload will be chosen to return a type. Will generate a compilation error if a field named name is not found.

Arguments

obj – a class or record
name – the name of a field

Returns

the type that field represents

proc getField(const ref x: ?t, param s: string) type

Get a field in a class or record by name. When the named field is a type variable, this overload will be chosen to return a type. Will generate a compilation error if a field with that name is not found.

Arguments

x – a class or record
s – the name of a field

Returns

the type that field represents

Warning

The formals ‘x’ and ‘s’ are deprecated, please use ‘obj’ and ‘name’ instead

proc getField(const ref obj: ?t, param name: string) const ref

Get a field in a class or record by name. Will generate a compilation error if a field named name is not found.

Arguments

obj – a class or record
name – the name of a field

Returns

an rvalue referring to that field.

proc getField(const ref x: ?t, param s: string) const ref

Get a field in a class or record by name. Will generate a compilation error if a field with that name is not found.

Arguments

x – a class or record
s – the name of a field

Returns

an rvalue referring to that field.

Warning

The formals ‘x’ and ‘s’ are deprecated, please use ‘obj’ and ‘name’ instead

proc getFieldRef(ref x: ?t, param i: int) ref¶

Get a mutable ref to the ith field in a class or record. Causes a compilation error if i is not in 0..<numFields(t) or if the argument is not mutable.

Arguments

x – a class or record
i – which field to get

Returns

an rvalue referring to that field.

proc getFieldRef(ref x: ?t, param s: string) ref

Get a mutable ref to a field in a class or record by name. Will generate a compilation error if a field with that name is not found or if the class or record is not mutable.

Arguments

x – a class or record
s – the name of a field

Returns

an rvalue referring to that field.

proc getFieldIndex(type t, param name: string) param: int¶

Get the index of a field named name in a class or record type t, or -1 if the field name is not found.

Arguments

t – a class or record type
name – the name of a field

Returns

an index usable in getField, or -1 if the field was not found.

proc getFieldIndex(type t, param s: string) param: int

Get a field index in a class or record, or -1 if the field is not found.

Arguments

t – a class or record type
s – the name of a field

Returns

an index usable in getField, or -1 if the field was not found.

Warning

The formal ‘s’ is deprecated, please use ‘name’ instead

proc hasField(type t, param name: string) param: bool¶

Returns true if a class or record has a field named name, or false otherwise.

Arguments

t – a class or record type
name – the name of a field

Returns

true if the field is present.

proc hasField(type t, param s: string) param: bool

Returns true if a class or record has a field named s, or false otherwise.

Arguments

t – a class or record type
s – the name of a field

Returns

true if the field is present.

Warning

The formal ‘s’ is deprecated, please use ‘name’ instead

proc isFieldBound(type t, param idx: int) param: bool¶

Returns true if the field at idx has been instantiated in a given class or record type t.

Arguments

t – a class or record type
idx – which field to query

Returns

true if the field is instantiated

proc isFieldBound(type t, param i: int) param: bool

Returns true if the given class or record’s ith field has been instantiated.

Arguments

t – a class or record type
i – which field to query

Returns

true if the field is instantiated

Warning

The formal ‘i’ is deprecated, please use ‘idx’ instead

proc isFieldBound(type t, param name: string) param: bool

Returns true if the field named name has been instantiated in a given class or record type t.

Arguments

t – a class or record type
name – the name of a field

Returns

true if the field is instantiated

proc isFieldBound(type t, param s: string) param: bool

Returns true if the given class or record’s field named s has been instantiated.

Arguments

t – a class or record type
s – the name of a field

Returns

true if the field is instantiated

Warning

The formal ‘s’ is deprecated, please use ‘name’ instead

proc canResolve(param fname: string) param: bool¶: Returns true if a function named fname taking no arguments could be called in the current scope.

proc canResolve(param fname: string, args ...) param: bool: Returns true if a function named fname taking the arguments in args could be called in the current scope.

proc canResolveMethod(obj, param fname: string) param: bool¶: Returns true if a method named fname taking no arguments could be called on obj in the current scope.

proc canResolveMethod(obj, param fname: string, args ...) param: bool: Returns true if a method named fname taking the arguments in args could be called on obj in the current scope.

proc canResolveTypeMethod(type t, param fname: string) param: bool¶: Returns true if a type method named fname taking no arguments could be called on type t in the current scope.

proc canResolveTypeMethod(type t, param fname: string, args ...) param: bool: Returns true if a type method named fname taking the arguments in args could be called on type t in the current scope.

proc getLineNumber() param: int¶: Returns the line number of the call to this function.

proc getFileName() param: string¶: Returns the file name this function was called from.

proc getRoutineName() param: string¶: Returns the name of the function this function was called from.

proc getModuleName() param: string¶: Returns the name of the module this function was called from.