root_field

Mirrors src/graphql/root-field.ts.

Helpers for pulling structured data out of a parsed operation: the root Field node, its arguments resolved against a variable map, and the names of its sub-selections.

ResolvedValue is the Gleam analogue of TypeScript’s unknown here — a tagged union of the JSON-shaped values an argument can take after variable substitution. The TS version returns Record<string, unknown>, which the proxy then feeds straight into endpoint handlers; this enum gives us the same coverage with type safety.

Types

ResolvedValue

JSON-shaped value an argument resolves to once variables have been substituted. Mirrors the unknown returned by resolveValueNode in the TS version.

pub type ResolvedValue {
  NullVal
  StringVal(String)
  BoolVal(Bool)
  IntVal(Int)
  FloatVal(Float)
  ListVal(List(ResolvedValue))
  ObjectVal(dict.Dict(String, ResolvedValue))
}

Constructors

```
NullVal
```
```
StringVal(String)
```
```
BoolVal(Bool)
```
```
IntVal(Int)
```
```
FloatVal(Float)
```
```
ListVal(List(ResolvedValue))
```

ObjectVal(dict.Dict(String, ResolvedValue))

RootFieldError

Errors root_field helpers can produce.

pub type RootFieldError {
  ParseFailed(parser.ParseError)
  NoOperationFound
  NoRootField
  InvalidNumberLiteral(String)
}

Constructors

```
ParseFailed(parser.ParseError)
```
```
NoOperationFound
```
```
NoRootField
```
```
InvalidNumberLiteral(String)
```
graphql-js silently allows Number.parseInt("x") to return NaN, but the lexer guarantees IntValue.value is digits-only. If we somehow see a value that doesn’t parse, surface it explicitly rather than fabricating zero.

Values

get_field_arguments

pub fn get_field_arguments(
  field: ast.Selection,
  variables: dict.Dict(String, ResolvedValue),
) -> Result(dict.Dict(String, ResolvedValue), RootFieldError)

Resolve a single field’s argument list to a Dict keyed by argument name. Variable references are looked up in variables; missing variables resolve to NullVal (graphql-js’s ?? null).

get_root_field

pub fn get_root_field(
  document: String,
) -> Result(ast.Selection, RootFieldError)

Return the first root Field selection of the document’s first operation. Mirrors getRootField.

get_root_field_arguments

pub fn get_root_field_arguments(
  document: String,
  variables: dict.Dict(String, ResolvedValue),
) -> Result(dict.Dict(String, ResolvedValue), RootFieldError)

Convenience wrapper around get_root_field + get_field_arguments. Mirrors getRootFieldArguments.

get_root_fields

pub fn get_root_fields(
  document: String,
) -> Result(List(ast.Selection), RootFieldError)

Return every root-level Field selection of the first operation. Mirrors getRootFields. Fragment spreads / inline fragments are dropped, matching the TS .filter(kind === Kind.FIELD).

get_selection_names

pub fn get_selection_names(field: ast.Selection) -> List(String)

Names of the top-level field selections inside a Field’s selection set. Mirrors getSelectionNames.

parse_operation_summary

pub fn parse_operation_summary(
  document: String,
) -> Result(
  parse_operation.ParsedOperation,
  parse_operation.ParseOperationError,
)

resolved_value_decoder

pub fn resolved_value_decoder() -> decode.Decoder(ResolvedValue)

resolved_value_to_json

pub fn resolved_value_to_json(value: ResolvedValue) -> json.Json