Archeometer v0.5.0

Archeometer.Query.Term (Archeometer v0.5.0)

Restrict and adapt Elixir terms to a subset that is translatable to SQLite expressions. See the language reference

The following literals are allowed

  • Integers
  • Floating point numbers
  • Bitstrings
  • Booleans
  • Lists

Plus some operators and functions

  • Boolean operators: and, or, not
  • Comparaison operators: ==, !=, <, >, <=, >=
  • Arithmetic operators: +, -, *, /
  • Arithmetic functions: round
  • Search functions: like
  • Null checking: is_nil, not is_nil
  • Aggregation functions: avg, count, max, min, sum
  • Subquery expressions: exists
  • in operator

And any kind of dot operator: m.some.key.or.attribute to represent table lookup. For example

max(m.num_lines, 10 * m.num_args)

m.cc > 10

like(m.name, "Archeometer.%") and m.name != "Archeometer.Query.Term"

Tuples and maps are allowed but only as a top level construct.

{m.name, m.num_lines, avg(m.functions.cc)} # this is valid
[name, num_lines * 10] # this as well

{m.name, {m.functions.name, m.functions.num_lines}} # this is not
[m.name, {m.num_lines}] # neither is this

Link to this section Summary

Functions

to_ast(validated_ast)

Takes a validated AST and tries to transformed into its original state.

to_iodata(ast)

Takes a validated AST and tries to transformed into an SQL-compatible io_data. The goal would be to obtain valid SQL just by calling IO.iodata_to_binary/1.

validate(ast)

Takes an AST and returns a validated AST.For the most part it is identical to the original, except with anotated symbols.lookups instead of dot operators.

Link to this section Functions

Link to this function

to_ast(validated_ast)

Takes a validated AST and tries to transformed into its original state.

Most of the metadata is long gone by this point, but at least the original structure is preserved.

Link to this function

to_iodata(ast)

Takes a validated AST and tries to transformed into an SQL-compatible io_data. The goal would be to obtain valid SQL just by calling IO.iodata_to_binary/1.

Link to this function

validate(ast)

Takes an AST and returns a validated AST.For the most part it is identical to the original, except with anotated symbols.lookups instead of dot operators.