repr

Module nu.core.repr.

Representation atoms: Python's string and number renderings.

Maps Python's builtins that render a value to text or to an alternate numeric notation onto Nu ScalarQueries. Pure compute; no Context effect of their own.

Builtins to cover (Python -> Nu):

• text: repr -> Repr, ascii -> Ascii, format -> Format
• numeric notation: bin -> Bin, hex -> Hex, oct -> Oct
• code points: ord -> Ord, chr -> Chr

Sorts: all ScalarQuery (Q).

Each atom defines compile (sync hot path) and acompile (async hot path). Both return a thunk (rt) -> value that captures the precompiled child thunks, so recursion skips the Runtime.eval / Runtime.aeval dispatch hop per child. Sentinel propagation is inlined: an EMPTY or INVALID operand collapses the result to INVALID without further compute.

Most atoms are unary over one child. Format mirrors Python's format(value[, format_spec]) and branches on child count: one child applies the empty format spec, two children apply the second child as the spec.

The module name repr shadows the builtin name as a module path (nu.core.repr); inside the module the builtin repr() still resolves normally.

Most of these have no prior atom yet, so they are built fresh against the builtins.

Ascii

The ascii string of its one child, with non-ASCII escaped.

Ascii(value)

Path nu.core.Ascii. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The ascii string. INVALID when the child is EMPTY or INVALID.

Notes

• Same as Repr except every non-ASCII code point comes back as a \xXX, \uXXXX or \UXXXXXXXX escape, so the result is always plain ASCII text.

Example

nu.run(nu.Ascii("café"))[0]

"'caf\\xe9'"

Bin

The binary string (0b...) of its one integer child.

Bin(value)

Path nu.core.Bin. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The binary string. INVALID when the child is EMPTY or INVALID.

Notes

• A negative value keeps its sign in front of the prefix, e.g. -10 renders as -0b1010, not a two's-complement bit pattern.

Example

nu.run(nu.Bin(10))[0]

'0b1010'

Chr

The character for its one integer code-point child.

Chr(value)

Path nu.core.Chr. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The character. INVALID when the child is EMPTY or INVALID.

Notes

• Always yields a one-character string, never a raw byte or int.

Example

nu.run(nu.Chr(65))[0]

'A'

Format

The format of a value under an optional format spec.

Format(value, spec)

Path nu.core.Format. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 2 (2 required).

Arguments

Yields

The formatted string. INVALID when either child is EMPTY or INVALID.

Notes

• One child applies the empty spec (format(value), usually the same as str(value)); two children apply the second as the spec mini-language string (format(value, spec)), e.g. .2f or >10.
• What a given spec means is up to the value's own __format__.

Example

nu.run(nu.Format(3.14159, ".2f"))[0]

'3.14'

Hex

The hexadecimal string (0x...) of its one integer child.

Hex(value)

Path nu.core.Hex. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The hex string. INVALID when the child is EMPTY or INVALID.

Notes

• A negative value keeps its sign in front of the prefix, e.g. -255 renders as -0xff, not a two's-complement bit pattern.

Example

nu.run(nu.Hex(255))[0]

'0xff'

Oct

The octal string (0o...) of its one integer child.

Oct(value)

Path nu.core.Oct. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The octal string. INVALID when the child is EMPTY or INVALID.

Notes

• A negative value keeps its sign in front of the prefix, e.g. -8 renders as -0o10, not a two's-complement bit pattern.

Example

nu.run(nu.Oct(8))[0]

'0o10'

Ord

The Unicode code point of its one single-character child.

Ord(value)

Path nu.core.Ord. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The code point, an int. INVALID when the child is EMPTY or INVALID.

Notes

• A string of any other length raises: this is not a bulk operation.

Example

nu.run(nu.Ord("A"))[0]

65

Repr

The repr string of its one child.

Repr(value)

Path nu.core.Repr. Kind ScalarQuery, sort scalar_query, cardinality scalar. Arity 1 (1 required).

Arguments

Yields

The repr string. INVALID when the child is EMPTY or INVALID.

Notes

• Delegates to Python's repr, so a string comes back quoted with its special characters escaped, and any type defining __repr__ renders however it chooses.

Example

nu.run(nu.Repr("hi"))[0]

"'hi'"