Enum LexerError 

#[non_exhaustive]
pub enum LexerError {
    UnexpectedCharacter,
    UnterminatedString,
    UnterminatedVarRef,
    InvalidEscape,
    InvalidNumber,
    InvalidFloatNoLeading,
    InvalidFloatNoTrailing,
    NestingTooDeep,
    UnterminatedCommandSubst,
    UnterminatedArithmetic,
    UnterminatedHeredoc {
        delimiter: String,
    },
    BackticksNotSupported,
    ArithmeticInVarRef,
    NonAsciiName {
        kind: &'static str,
        text: String,
    },
    HashInsideWord,
}

Lexer error types.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

UnexpectedCharacter

UnterminatedString

UnterminatedVarRef

InvalidEscape

InvalidNumber

InvalidFloatNoLeading

InvalidFloatNoTrailing

NestingTooDeep

Nesting depth exceeded (too many nested parentheses in arithmetic).

UnterminatedCommandSubst

A $( opened inside a double-quoted string and the input ended before its ). Reported instead of UnterminatedString because the missing ) is the error and the unterminated string is only its consequence: echo "pre $(echo hi" is a forgotten paren, not a forgotten quote.

UnterminatedArithmetic

Arithmetic expansion $(( reached end of input without a closing )). Silently evaluating the partial expression would mask a typo ($(( 1 + 2 would compute 3), so we surface it loudly instead.

UnterminatedHeredoc

Heredoc body ended without seeing the closing delimiter on its own line. The user almost certainly meant to type the delimiter — silently using whatever was collected up to EOF would mask missing data.

Fields

delimiter: String

BackticksNotSupported

Backtick command substitution. Kaish drops backticks intentionally — they’re listed in docs/LANGUAGE.md and the help system as not supported. We surface this as a dedicated error (rather than UnexpectedCharacter) so the message can point users at the $(cmd) replacement.

ArithmeticInVarRef

$((expr)) inside a bare ${...} reference (e.g. ${X:-$((1+2))}). There is no representation for arithmetic inside a variable reference — the pre-#95 pipeline silently leaked internal marker text here — so it is a loud error instead. (Inside double-quoted strings the same construct works via string interpolation.)

NonAsciiName

A -flag/--flag/+flag word matched but contained a non-ASCII character. Flag names are ASCII-only; see the note on Token. kind is always "flag" — it stays a field because the message reads off it, and a second ASCII-only name class would use the same shape. text is the whole matched word (sigil included).

Fields

kind: &'static str

text: String

HashInsideWord

A # that is not at the start of a word — $x#3, "abc"#3, $(f)#3. POSIX opens a comment only at a word start, and the word classes carry # as an ordinary character, so a # that reaches this error follows something that cannot absorb it. Commenting from here would drop the rest of the line, ; separators and whole commands included, at exit 0.

Trait Implementations

impl Clone for LexerError

fn clone(&self) -> LexerError

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LexerError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for LexerError

fn default() -> LexerError

Returns the “default value” for a type.

impl Display for LexerError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for LexerError

fn eq(&self, other: &LexerError) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for LexerError