> expression patterns_
// the pattern:
declare_pattern
≔ "√" %W- <number> ⇒ float
➞ square_root (number);
// the usage:
if (n ∈ N ∧ n ≥ 0)
print (√n);
// the patterns:
declare_pattern
do_times_loop ≔
"do" <instruction>
"(" <integer>:times ")" "times"
⇒ loop ➞
{
for (int i = 1; i ≤ times; i++)
execute (instruction);
};
// the usage:
do {
print ("hello π!");
} (10) times;
> instruction patterns_
// the pattern:
declare_pattern sql_insert_statement ≔
"INSERT" "INTO" sql_table_name
"(" sql_column_name
{"," sql_column_name}:column_names
")" "VALUES" "("
sql_value {"," sql_value):values
")" ";"
⇒ sql_instruction ➞
{
check (size_of(column_names) = size_of(values),
"Wrong number of values!");
send_sql_command (current_database(), this);
};
// the usage:
INSERT INTO people VALUES ("Alfred", "Wissel"),
("Julika", "Häuser");
> DSL patterns_