Merge pull request #14 from knowsys/sparql

Documentation for preliminary SPARQL query support

Author: mmarx

src/content/docs/reference/builtins.md

@@ -28,6 +28,8 @@ that starts at the given index and extends to the end of the string. Optionally,
 - `STRENDS`: checks if the string given as the first parameter ends with the string given as the second parameter
 - `CONTAINS`: checks if the string given as the first parameter contains the string given as the second parameter
 - `REGEX`: checks if the string given as the first parameter matches the regular expression given as second the parameter
+- `URIENCODE`: transforms the given string according to the rules of [RFC 3986, Section 2.1](https://www.rfc-editor.org/rfc/rfc3986#section-2.1), making it suitable for use as part of the query string of a URI by percent-encoding all characters except `-`, `_`, `.`, and `~`.
+- `URIDECODE`: decodes a string transformed by `URIENCODE` back to the original, unencoded version.
 
 ### Format Strings
 
@@ -128,4 +130,4 @@ result(?x, ?y) :- r(?x, ?y), OR(NUMGREATER(?x, 2), EQUALITY(?y, 0)).
 
 % Invalid rule
 % result(?x, ?y) :- r(?x, ?y), OR(?x > 2, ?y = 0).
-```
+```

src/content/docs/reference/datatypes.md

@@ -12,7 +12,7 @@ mydata("3.14"^^xsd:double, "2023-06-19"^^xsd:date) .
 ```
 
 However, it is often nicer to use the shortcuts:
-- *Strings* can be written in `"double quotes 🙂"` and support Unicode.  
+- *Strings* can be written in `"double quotes 🙂"` and support Unicode. Multi-line strings can also be written using `"""triple quotes"""`.
 - *Integers* can be written as plain numerals with an optional sign: `42`, `-23`, `+911` all work.
 - *Double precision floats* can be written with decimal point and optional exponent: `3.14`, `.05`, `10.345E6` all work.
 - *Language-tagged strings* are written like in RDF, e.g., `"Dresden"@de` or `ドレスデン@ja`.

src/content/docs/reference/exports.md

@@ -51,3 +51,8 @@ Besides the above, there are format-specific parameters:
 | `format` | `csv`, `dsv` | The output-format of the exported data. Might be `int`, `double`, `string`, `rdf` or `skip`. |
 
 When using the [Nemo command-line client](/nemo-doc/guides/cli), some cli options are available to override the export directives in the program, to set the output (base) directory, and to control if existing files should be overwritten.
+
++The parameters in export directives can also make use of format strings, e.g.,
++```
++@export table :- csv{resource = f"file-{?x}-{?y}.csv"}, ?x = "name", ?y = 42 .
++```

src/content/docs/reference/imports.md

@@ -9,7 +9,7 @@ Nemo allows importing external data files as predicates. The general syntax for
 
 Here, `table` denotes the predicate that data is imported to, `csv` is the data format (comma-separated values),
 and `path/to/file.csv` is the path to the file. Instead of a local path, it is also possible to define a URL from
-which data should be downloaded, e.g., `resource = <https://example.org/file.csv>`.
+which data should be downloaded, e.g., `resource = "https://example.org/file.csv"`.
 
 The following formats are currently supported:
 - Delimiter-separated values: `csv`, `tsv` (tab-separated), `dsv` (delimiter required as parameter, e.g., `delimiter=";"`)
@@ -66,4 +66,10 @@ Import directives support various other optional parameters:
 - `limit`: if specified, only at most this many tuples are imported (great for testing when working with large files)
 - `compression`: used to define a compression format (`gzip` or `none`); this will normally be guessed correctly from the file extension, but can be useful for non-standard file names or URLs
 - `delimiter`: only for import format `dsv`, specify a delimiter string (should be a single character)
+- `ignore_headers`: only for import formats `csv`, `dsv`, and `tsv`, if true, the first record (containing the column headers) is ignored
 - `base`: specify the base IRI to be used when importing RDF data; if given, relative IRIs will be made absolute based on this base; otherwise, relative IRIs remain relative in Nemo
+
+The parameters in import directives can also make use of format strings, e.g.,
+```
+@import table :- csv{resource = f"file-{?x}-{?y}.csv"}, ?x = "name", ?y = 42 .
+```