Tags reference

Every tag in the TDC DSL, and where each one is covered in depth.

Structure

Tag	What it is	See
<!--…-->	A comment	—
<tdc>	The root element	Configuration
<env>	The environment: parameters, sequences, fixtures	Configuration
<sequence>	A named sequence declaration	Sequences
<gen>	A data generator	Generators
<data>	Inside a <sequence>: literal text joined into the sequence's value, or — with a name — a constant field	Sequences
<compute>	A computed value	Compute Language

Output layout

Tag	What it is	See
<block>	The layout of one output record	Output & formatting
<line>	One line inside a record	Output & formatting
<data>	Inside a <line>: literal text with interpolation	Output & formatting
<before> / <after>	Text before / after the whole run	Output & formatting
<before_block> / <after_block> / <delimiter_block>	Text around / between records	Output & formatting
<before_line> / <after_line> / <delimiter_line>	Text around / between lines	Output & formatting

Distributions and choice

Tag	What it is	See
<mix>	A distribution: a value split by exact percentages	Distributions (mix)
<switch>	A lookup table: a value picked by key	Lookup tables (switch)
<map>	A compact KEY:VALUE table inside <switch>	Lookup tables (switch)
<case>	One branch inside <mix> or <switch>	Distributions (mix) · Lookup tables (switch)
<default>	The "else" branch inside <switch>	Lookup tables (switch)

Whole records

Tag	What it is	See
<pool>	A small table built before the rows; a row draws one whole member from it	Coherent records (pool)

Uniqueness

Tag	What it is	See
<distinct>	Fields or sequences that must differ within one row	No repeats within a row
<uniq>	A combination of sequences that must be unique across all rows	Unique values

<data> is listed twice because it reads two ways. Inside a <line> it is output: literal text with ${{…}} interpolated into it. Inside a <sequence> it is data: bare, it is the glue between the generators of a composed sequence; with a name, it is a constant field and the only field that costs no draw.

Compute tags (the ones that go inside <compute>) have their own list in the Compute functions reference.