Error Reference

Phel compiler errors are tagged with a stable code like [PHEL001]. The code survives wording changes, so it is the reliable thing to search for. An error prints as the code, a message, the source location, a snippet of the offending code, and often a hint:

[PHEL001] Cannot resolve symbol 'maap'. Did you mean 'map'?
in src/app.phel:12

Codes are grouped by the compiler stage that raises them.

Analyzer errors#

Raised while analyzing forms: undefined names, wrong arity, type and binding problems. The bulk of day-to-day errors.

PHEL001 : Undefined symbol#

A symbol could not be resolved to a definition in the current scope.

Common cause: A typo, a missing (:require ...) for the namespace the symbol lives in, an alias that does not match, or using a binding before it is defined.

Fix: Check the spelling, require the namespace (e.g. (:require phel\string :as str) for str/...), or move the definition above its first use. The error message suggests near matches.

PHEL002 : Arity error#

A function was called with the wrong number of arguments.

Common cause: The call site passes more or fewer arguments than any of the function's arities accept.

Fix: Match the call to a declared arity. For variadic functions use & rest in the parameter vector.

PHEL003 : Type error#

A form received a value of the wrong type.

Common cause: For example attaching metadata that is not a String, Keyword or Map, or passing a non-collection where a collection is required.

Fix: Pass the type the form expects. The message names the value it got.

PHEL004 : Def not allowed#

def was used somewhere it is not allowed.

Common cause: def defines a top-level var, so it cannot appear nested inside a function body or another expression.

Fix: Move the def to the top level of the namespace. For function-local values use let.

PHEL005 : Macro expansion error#

A macro threw while expanding.

Common cause: The macro received arguments it did not expect, or its own body raised during expansion.

Fix: Check the arguments at the call site and inspect the expansion with (macroexpand '(your-form ...)).

PHEL006 : Inline expansion error#

An inline-expanded function failed to expand.

Common cause: A function declared with an :inline implementation produced an invalid expansion for the given call.

Fix: Call the function within the shape its :inline definition supports, or report it upstream if it is a core function.

PHEL007 : Invalid special form#

A special form was written in an invalid shape.

Common cause: A core form such as if, let, fn, do or quote was given the wrong structure (missing or extra parts).

Fix: Match the form's grammar, e.g. (if test then else?), (let [bindings*] body*).

PHEL008 : Binding error#

A binding vector is invalid.

Common cause: An odd number of binding forms in let/loop, or a binding target that cannot be destructured.

Fix: Provide an even number of name value pairs and use valid destructuring targets (symbols, vectors, maps).

PHEL009 : Interface error#

An interface or protocol definition (or its implementation) is invalid.

Common cause: A malformed definterface/defprotocol, or trying to implement a defprotocol inline in defstruct (only definterface can be implemented inline).

Fix: Use definterface for inline implementation, or defprotocol plus extend-type per struct.

PHEL010 : Recur error#

recur was used incorrectly.

Common cause: recur appeared outside a loop/fn tail position, or with an argument count that does not match the recursion point.

Fix: Use recur only in tail position, with as many arguments as the enclosing loop/fn binds.

PHEL011 : Not callable#

A value that is not a function was called.

Common cause: A non-callable value (a number, string, keyword used wrongly) sits in the head position of a list, often an extra pair of parentheses.

Fix: Remove the stray parentheses, or put a function in the call position.

Parser errors#

Raised while parsing tokens into forms, almost always an unbalanced or unterminated bracket.

PHEL100 : Unterminated list#

A list was not closed.

Common cause: A missing ).

Fix: Balance the parentheses. Editor rainbow-brackets or phel format help spot it.

PHEL101 : Unterminated vector#

A vector was not closed.

Common cause: A missing ].

Fix: Balance the brackets.

PHEL102 : Unterminated map#

A map was not closed.

Common cause: A missing }, or an odd number of key/value forms.

Fix: Close the brace and ensure every key has a value.

PHEL103 : Unterminated table#

A table literal was not closed.

Common cause: A missing closing brace on a @{ ... } table literal.

Fix: Close the table literal.

PHEL110 : Unexpected token#

A token appeared where the parser did not expect one.

Common cause: A stray closing bracket, or a reader macro applied to nothing.

Fix: Remove or complete the offending token.

PHEL120 : Parser error#

A general parser error.

Common cause: The token stream could not be assembled into valid forms for a reason not covered by a more specific code.

Fix: Check the indicated location for malformed structure.

Reader errors#

Raised while reading quote / quasiquote forms.

PHEL200 : Invalid quote#

A quote form is malformed.

Common cause: quote was given the wrong number of arguments.

Fix: Use (quote x) or the 'x shorthand with a single form.

PHEL201 : Invalid unquote#

An unquote (~) is invalid.

Common cause: ~ was used outside a quasiquote (`) or with a wrong argument shape.

Fix: Only use ~ inside a quasiquoted form.

PHEL202 : Invalid splice#

A splicing unquote (~@) is invalid.

Common cause: ~@ was used outside a quasiquote, or in a position where a sequence cannot be spliced.

Fix: Use ~@ inside a quasiquote, splicing into a list or vector.

PHEL210 : Reader error#

A general reader error.

Common cause: A reader macro could not be read for a reason not covered by a more specific code.

Fix: Check the quote/quasiquote forms at the indicated location.

Lexer errors#

Raised while turning source text into tokens: invalid characters or unterminated strings.

PHEL300 : Invalid character#

An invalid character was found in the source.

Common cause: A character that is not valid Phel syntax at that position.

Fix: Remove or escape the character.

PHEL301 : Unterminated string#

A string was not closed.

Common cause: A missing closing ", sometimes from an unescaped quote inside the string.

Fix: Close the string and escape interior quotes as \".

PHEL310 : Lexer error#

A general lexer error.

Common cause: The source could not be tokenized for a reason not covered by a more specific code.

Fix: Check the indicated location for stray or invalid characters.