Error codes

Every diagnostic TDC can raise, listed by code. Look one up when a run stops and the message alone isn't enough.

How to read a diagnostic

A diagnostic carries four things. The code is the part that never changes between versions — the wording may improve, but TDC193 stays TDC193:

./run demo.tdc

error[TDC193]: "Naem" is not a declared sequence — it would be printed literally
--> demo.tdc:8:11
|
8 |     <line><data>${{Naem}}</data></line>
|           ^^^^^^^^^^^^^^^^^^^^^^
|
help: did you mean "Name"?
note: Declare it in <env>, or set a different inject= pattern if you really want the text ${{…}} in the output.

• the code — what went wrong, stable across releases;
• the place — file, line, and column, with the offending element underlined;
• help: — a guess at what you meant, when the name is a near miss;
• note: — what to do about it.

Validation runs before generation, so a config with errors produces no data at all rather than half a file. Almost every diagnostic here is an error and stops the run: if the config asked for something it wouldn't actually get, TDC refuses rather than handing back data that looks right but isn't. The exceptions are seven warnings that let the run finish: TDC136 (a malformed <map> row is skipped and the valid rows still apply), TDC171 (a pack file whose header puts it at no address), TDC200 (a memory estimate that is large but still fits), TDC216 (an expression that is always true or always false), TDC221 (a <uniq> or <distinct> group with one member, which constrains nothing), TDC231 (a <pool> nothing reads) and TDC234 (a pool over 100,000 members). Each says as much in its row below.

The numbers run roughly in the order a config is checked — structure first, then generators, then everything built on top of them — but a number is an identifier, not a classification. Use the groups below.

Document structure

Code	Fires when	Fix
TDC001	The file has no <tdc> root	Wrap everything in a single <tdc>…</tdc>
TDC002	<tdc> has no <block> child	Add the <block> that describes one record's layout
TDC003	Both version and v are given on <tdc>	Keep one — they're aliases
TDC004	The declared document version isn't a valid version number	Use a version this runtime supports, e.g. v="0.1" (a value newer than the runtime raises TDC005)
TDC005	The file asks for a version newer than this runtime	Upgrade TDC, or lower the declared version
TDC010	A tag other than <env> or <block> sits directly under <tdc>	Move it inside one of those two
TDC013	A tag is nested somewhere it isn't allowed	See Tags for what may contain what
TDC014	A tag that has to hold children is written self-closing	Write <env …></env>, not <env …/> — its children would be silently dropped
TDC015	A tag carries an attribute the engine doesn't read	The run stops, because the config asked for something it wouldn't get. Check the spelling — the message suggests the nearest real name
TDC020	count isn't a non-negative integer	count="1000"
TDC021	An inject pattern has no % placeholder	The marker needs a % for the name, e.g. inject="[[%]]"

Sequences

Code	Fires when	Fix
TDC030	A tag that requires a name doesn't have one	Add name="…"
TDC031	A sequence name starts with _	That prefix is reserved for built-ins
TDC032	Two sequences share a name	Rename one — references to it would be ambiguous
TDC033	A name collides with a built-in	Pick another one; built-ins always win
TDC034	A parent value isn't in Parent.Value form	Use the two-part form, e.g. parent="Gender.Male"
TDC035	The parent sequence is declared after this one	Move the parent above it — resolution is top-down
TDC214	parent= names a compound sequence	A parent is filtered by the value it produced, and a group of fields produces none
TDC036	A <sequence> has no <gen> inside it	A sequence needs a generator to produce anything
TDC110	retired — an unnamed <gen> beside a named one now composes rather than failing	—
TDC111	Two fields of one compound sequence share a name	Rename one
TDC129	A <sequence> inside a config-level tag produces nothing usable there	See Sequences

Generators

Code	Fires when	Fix
TDC040	A <gen> has no type	Add type="…" — see Generators
TDC041	The type is unknown, or isn't supported on an inline <gen>	Check the spelling; TDC suggests the nearest name
TDC050	type="text" without value	Give it the list, e.g. value="a,b,c"
TDC051	A percent on a value list has more entries than the list has values	One percentage per value, e.g. value="a,b" with percent="70,30"
TDC052	A percent entry isn't a non-negative number	Every filled position has to be a number; an empty position splits what's left equally
TDC053	The percent values don't add up to 100	Adjust them to total 100, or leave a position empty to absorb the remainder
TDC060	type="file" without src	Point src at the file
TDC061	The file can't be read	Check the path — it's relative to the config file — or use --data-path
TDC062	column doesn't resolve	Use a header name (column="email") or a 1-based index (column="2")
TDC064	row is used without column	Row linking needs to know which CSV column to draw from
TDC065	type="http" without src	Point it at the service — src="http://127.0.0.1:5566/gen"
TDC066	src isn't an http(s) URL	Use http://… or https://…, with a host and a path
TDC067	in= names nothing that was declared before it	The value sent with each row has to come from an earlier <sequence>
TDC068	on_error is neither fail nor empty	fail (default) stops the run; empty blanks the cell
TDC070	type="template" without value	Give it the dotted address, e.g. value="person.lastName"
TDC071	The template address is unknown	Check the spelling, or install the pack that provides it
TDC072	value="date.range" without range, or a type="template" parameter the pack doesn't declare	Add range="…", or check the parameter name — the message lists the ones the pack accepts
TDC073	A legacy range isn't two valid dates	Use YYYY.MM.DD - YYYY.MM.DD
TDC081	A number range is malformed	value="10..99"
TDC082	first_zero isn't true or false	Those are the only two values
TDC083	length isn't a count, a range, or a comma-separated list	e.g. length="8", length="6..9", length="4,6,8"
TDC084	A percent on a numeric value has more entries than the range allows	One percentage per value
TDC085	A percent entry on a number isn't a non-negative number	Every filled position has to be a number
TDC086	The percent values on a number don't add up to 100	Adjust them to total 100
TDC087	include/exclude without a numeric range in value	They filter a range, so there has to be one
TDC088	distribution is combined with an attribute it rules out	A named distribution shapes the draw on its own
TDC089	The distribution parameters are wrong	See Distributions
TDC090	An attribute that has to be a number isn't one	Check the value
TDC095	type="regex" without value	The pattern goes in value
TDC096	regex_max_length isn't a positive integer	e.g. regex_max_length="64"
TDC097	The regex doesn't parse	Fix the pattern — the parser's own message follows
TDC098	type="symbol" is given both value and alphabet, or neither	Give exactly one: an inline set in value, or a named alphabet
TDC099	The named alphabet is unknown	See Symbol
TDC128	type="advanced_regex" without value	The pattern goes in value
TDC128	(second meaning) default= or if= written on a <case>	A <mix> picks its case by percentage and a <switch> by the is key — neither asks a condition. For condition-driven values use a <sequence> with <gen if="…"> branches
TDC130	The advanced pattern doesn't parse	See Advanced regex
TDC244	type="pattern" with no points, src or upper	A drawing needs a shape to read: points="0,0 1,5 2,3", a file in src, or upper/lower for a band

Expressions in if

Code	Fires when	Fix
TDC100	The expression doesn't parse	See Output & formatting
TDC101	A binary operator isn't supported	Supported: == != === !== < > <= >= && || + - * /
TDC102	A unary operator isn't supported	Supported: !, -, +
TDC103	The expression uses computed member access	Only plain names are allowed
TDC215	A name in an if= that no sequence has	It reads as its own text: alone the branch always fires, compared it never does
TDC216	(warning) if="Seq.Value" names a value the sequence never produces	The branch is dead. A warning, not an error: a list narrowed on purpose is a real thing to write
TDC217	A template path exists, but not for the run's locale	The message names the locale; set local= on the <gen> or <env>, or pick a path your locale ships
TDC218	uniq="true" on a sequence with no values of its own — <compute> reads other sequences, if= picks a branch per row	Put uniq= on the sequences it reads, or wrap them in <uniq>
TDC219	A <compute> and a <gen> in the same <sequence> — one of them would be dropped	Move the <compute> into its own <sequence> and read the drawn one with <field>
TDC220	uniq="true" on a composed value joining two or more drawn parts	The parts have no fixed width, so a unique set of parts is not a unique string: 9+15 and 91+5 are the same three characters. Keep one drawn part, or make the widths fixed
TDC221	(warning) A <uniq> or <distinct> around fewer than two <sequence>s	A group constrains its members against each other, so one member constrains nothing. Add a second member, or write uniq="true" on the sequence itself

<pool>

See Coherent records.

Code	Fires when	Fix
TDC222	A <pool> with no name, or with no count	A pool is read by name and holds a fixed number of members: <pool name="Doctors" count="30">
TDC223	A <pool count="…"> that is not a whole number of at least 1	A pool of nothing has no member to hand out
TDC224	<gen type="pool" value="X"> where no <pool name="X"> is declared	The message lists the declared pools. Declare it in the same <env>
TDC225	filter="field == X" where the two sides can never hold a common value	Both lists are written in the config, and they do not meet — so every row is narrowed to no member at all. The message names both. Only a certain contradiction is reported here; a value that merely comes up rarely is refused at the row that draws it
TDC226	filter= reads Pool.field and the pool has no such field	The message lists the pool's fields. An unqualified unknown name is left alone — the expression language reads a bare word as a literal
TDC229	${{Ref}} where Ref draws a whole member	A member is a record, not a value. Read a field: ${{Ref.lastName}}
TDC230	A <block>, a fixture tag, or another <pool> inside a <pool>	A pool is a table other columns read, not something written to a file, and pools do not nest
TDC231	(warning) A <pool> no <gen type="pool"> reads	It is built in full before the first row and kept in memory for the whole run, so an unread one is paid for and thrown away. Read it, or remove it
TDC232	A name in filter= that is both a field of the pool and a sequence	Rename one of them. Qualifying one side does not help — the other name still reads as the member's field, so the test compares a value with itself
TDC234	(warning) Over 100,000 members	A pool stays in memory for the whole run — about 320 bytes a member with four fields. If you meant the number of ROWS, that is count on <env>
TDC235	Over 1,000,000 members	Same cause, past the point where it is worth running. Reduce the pool, or move the number to <env count="…">
TDC236	(warning) uniq="true" over 100,000 rows	Drawing without replacement means remembering what has been drawn, so the whole column stays in memory and the run cannot stream. Measured at about 250 bytes a value — 2,000,000 rows cost about 477 MB. It works; it is worth being deliberate about
TDC236	A pool reads a pool declared below it, or itself	Pools are built in declaration order, so a pool can only read the pools above it. Move the one it reads up. That order is also why a cycle between pools cannot be written down
TDC241	Two pools declared under one name	A pool is reached by name, so two cannot share one. The second used to replace the first in silence, and the only sign was a TDC193 in the block about a field that "does not exist"

Three numbers in this range were reserved while pools were being designed and will stay unused, so the gaps are declared rather than silent:

• TDC227 — filter= naming a column that does not exist. A bare word in the expression language has always been a string literal, and that is what filter="clinic == North" uses to say "northern only". A typo and a literal are the same thing written down, so the check would put an error on working configs. Where the literal is a certain mistake — no member could ever hold that value — TDC225 says so instead, without guessing.
• TDC228 — ${{Pool.field}} addressing a pool without going through a reference. TDC193 already reports it as a name that resolves to nothing, and a second code for the same sentence is not worth the number.
• TDC233 — no candidate passed filter= on row N, for expressions richer than a simple equality. That refusal happens and is worth having; it just is not a diagnostic code. It compares against a value that only exists once the row is being built, so it belongs to the run, and the run's message names the row and the value that matched nobody.

Running totals

See accumulate= and <gen type="running">.

Code	Fires when	Fix
TDC237	accumulate= on a generator with no repeat=	There is no list to accumulate. Add repeat="N", or drop accumulate=. (type="running" is exempt — it accumulates down a column)
TDC238	accumulate= names an operation that does not exist	One of sum, min, max
TDC239	<gen type="running"> does not say what (of=) or how (accumulate=) to accumulate	A running total reads another column and draws nothing of its own, so both are required
TDC240	of= or reset= names a column not declared above	The total is built from a column that already exists — the same rule parent= follows

<compute>

Code	Fires when	Fix
TDC180	A tag inside <compute> that the compute language does not have, or a predicate written outside <test>	The message names the tag. Check it against the compute reference — a predicate such as <eq> is valid only inside <test>
TDC181	<current>, <current_index>, or <acc> is used outside its iteration body	They exist only inside a <do> (or a <reduce>'s <do>)
TDC182	<var name="X"> names no enclosing <let>	Wrap it in <let name="X">…</let>, or fix the name
TDC183	A binary compute op has the wrong number of children	<add>, <subtract> … take exactly two operands
TDC184	<choose> has no <otherwise> branch	Add <otherwise> — every record needs an answer
TDC185	A <let name="X"> shadows an outer binding of the same name	Rename one — the inner binding would hide the outer one
TDC186	<encode>: unknown encoding	One of: base36, ascii, unicode, hex, binary, octal
TDC187	A predicate is missing its wrapper child	<when> wants <test>, <choose> wants <then> — the message names the pair
TDC188	<int v="…"> isn't a whole number	Write a whole number; for text, use <str v="…"/>
TDC189	<compute> has more than one <result>	Keep a single <result> — the earlier ones would be dropped

<mix>, <switch>, fixtures

Code	Fires when	Fix
TDC120	<mix> has no <case>	A mix needs branches to pick between
TDC121	A percent on a <mix>/<switch> has more entries than there are cases	One percentage per case
TDC122	A percent entry on a <mix>/<switch> isn't a non-negative number	Every filled position has to be a number
TDC123	The percent values on a <mix>/<switch> don't add up to 100	Adjust them to total 100
TDC124	<mix> has a child that isn't a <case>	Only <case> belongs there
TDC125	<case> has an unknown child	Allowed: <data>, <gen>, <mix>
TDC131	A fixture contains a tag that fixtures don't accept	Fixtures hold <line> and <data> only
TDC132	A tag that doesn't belong there sits inside <line>	The output block is for layout — generators live in <env>
TDC133	<switch> has no on	Name the sequence being switched on
TDC134	on names a sequence, or a field of one, that doesn't exist	Check the name — the message says which half is wrong
TDC135	<switch> has no entries	Add a <map>, <case>, or <default>
TDC136	(warning) A <map> row isn't KEY:VALUE — the bad row is skipped and the rest of the map still applies	One pair per entry, separated by a colon
TDC137	A <case> inside <switch> has no is	is is the branch key
TDC245	name on a <switch> written inside a <case>	The nested form contributes a value to that branch; only an env-level <switch> becomes a column

Dates

Code	Fires when	Fix
TDC150	Only one of from / to is given	Give both endpoints or neither
TDC151	The date value doesn't parse	value="2020-01-01..2025-12-31", "birth", "today", "now"
TDC152	A format token is unknown	See the token table
TDC153	local names a locale with no date data	Built in: en, es, ru, zh-cn
TDC154	precision isn't a supported step	See precision

While rendering

These are raised during generation rather than validation — the config is well-formed, but the combination it asks for can't be carried out.

Code	Fires when	Fix
TDC160	row="…" is used on an inline <gen>	Row linking needs a <sequence>
TDC161	Weighted advanced_regex choices are used inline	Exact percentages need the whole column — move it into a <sequence>
TDC162	An inline counter's value or step isn't numeric	value="1" step="2"
TDC170	A data-pack file can't be loaded	The message names the file — see Writing your own
TDC171	(warning) A data-pack file lands at no address, so it is skipped	Add address: or locale: to its header, or move it under a locale folder
TDC200	(warning) The estimated memory use is a large share of this machine's RAM — the run continues	For very large sets, use mode="disk", which keeps memory flat
TDC201	The estimated memory use is more than this machine's RAM	Lower count, batch the run, or use mode="disk"

Three of these cannot be reached from a config

TDC160, TDC161 and TDC162 describe an inline <gen> — one written directly inside <line> rather than in a <sequence>. Validation refuses that shape first, with TDC131 (a <gen> is not allowed inside <line>) or TDC013, so a real config never gets far enough to raise them. They are reachable only through the low-level render(parse(src).tree) export, which walks an unvalidated tree on purpose. That is also why the four ports do not have them: they compile a config into a model that has no place to put such a <gen>.

Formatting and modifiers

Code	Fires when	Fix
TDC190	case isn't a known transform	upper, lower, capitalize, title
TDC191	order is neither random nor sequential	Those are the only two values
TDC192	An interpolation filter is unknown	See Masks & case
TDC193	${{Name}} or ${{Name.field}} names nothing that was declared	It would print literally — the whole reference is checked, field and all
TDC194	A typed <data> has no name	Only a named <data> becomes a column
TDC195	repeat isn't a count or a range	repeat="3" or repeat="1..5" (0 to 64)
TDC196	repeat is used on a <mix>	A mix picks one branch; it doesn't produce a list
TDC198	separator without repeat	It joins repeated values, so there have to be some
TDC199	A mask index is malformed	Indices are 0-based and ranges use .. — x[0..3], w[-1]
TDC202	flag is set but no <case> is marked anomaly="true"	The column would be all-negative — mark the outlier branch
TDC203	flag is used on a nested <mix>	Only a named env-level mix carries the answer column
TDC204	repeat is used on a generator that can't repeat	The message names the type
TDC206	each="" names no sequence	Name the list to walk
TDC207	each names a single-value sequence	It has to be a list — add repeat to the source
TDC209	A named <data> sits inside an each= line	That line produces several rows, so a column name is ambiguous
TDC211	weight is used on a generator other than file	Weights come from a CSV column
TDC212	weight without column	The weights live in a second column, which has to be named
TDC213	weight is combined with order	order walks the rows by position; weighting picks them by frequency
TDC242	anomaly or missing isn't a number in [0, 1]	Both are a SHARE of the values: anomaly="0.05", missing="0.1"
TDC243	anomaly on a value list with no number in it	An anomaly multiplies a number, so a list of words comes back unchanged

See also

• CLI — exit codes and flags
• Tags and Attributes — what's allowed where