OpenEuphoria

Extract variables from a string according to a template

• Posted by jmduro Sep 07, 2022
• 901 views

Hello, I wrote a library named extract_vars.e to extract variables from a string according to a template, with multiple levels of options. It is available here: http://jean-marc.duro.pagesperso-orange.fr/extract_vars.zip with a test program.

It is called this way:

sequence vars = extract_vars(code, template) 

It returns a list of variables with some details:

• KEY : variable name in the template
• LEVEL: option level in the template (0=not optional)
• VALUE: variable value in the string
• PMIN : variable starting position in the string
• PMAX : variable ending position in the string

Here are some examples of usage:

template: http://<url>[:<port>]/search?q=<query> 
 
code    : http://www.google.com/search?q=euphoria 
vars = 
  [1] {"<url>", 0, "www.google.com", 7, 22} 
  [2] {"<query>", 0, "euphoria", 31, 39'''} 
 
code    : http://www.google.com:80/search?q=euphoria 
vars = 
  [1] {"<url>", 0, "www.google.com", 7, 22} 
  [2] {"<port>", 1, "80", 22, 25} 
  [3] {"<query>", 0, "euphoria", 34'"', 42'*'} 
 
-------------------------------------------------------------------------------- 
 
template: class <name>([<parent>]) 
 
code    : class TWin32() 
vars = 
  [1] {"<name>", 0, "TWin32", 5, 13} 
 
code    : class TWindow(TWin32) 
vars = 
  [1] {"<name>", 0, "TWindow", 5, 14} 
  [2] {"<parent>", 1, "TWin32", 14, 21} 
 
-------------------------------------------------------------------------------- 
 
template: [<prefix> ]function <name>(<a>[, <b>[[=<c>], <d>[=<e>]]]) 
 
code    : function test(sequence list) 
vars = 
  [1] {"<name>", 0, "test", 8, 14} 
  [2] {"<a>", 0, "sequence list", 14, 28} 
 
code    : function test(sequence list, sequence key, sequence value=0) 
vars = 
  [1] {"<name>", 0, "test", 8, 14} 
  [2] {"<a>", 0, "sequence list", 14, 28} 
  [3] {"<b>", 1, "sequence key", 28, 42'*'} 
  [4] {"<d>", 2, "sequence value", 42'*', 58':'} 
  [5] {"<e>", 3, "0", 58':', 60'<'} 
 
code    : function test(sequence list, sequence key="default") 
vars = 
  [1] {"<name>", 0, "test", 8, 14} 
  [2] {"<a>", 0, "sequence list", 14, 28} 
  [3] {"<b>", 1, "sequence key", 28, 42'*'} 
  [4] {"<c>", 3, "\"default\"", 42'*', 52'4'} 
 
code    : function test(sequence list, sequence key="default", sequence value=0) 
vars = 
  [1] {"<name>", 0, "test", 8, 14} 
  [2] {"<a>", 0, "sequence list", 14, 28} 
  [3] {"<b>", 1, "sequence key", 28, 42'*'} 
  [4] {"<c>", 3, "\"default\"", 42'*', 52'4'} 
  [5] {"<d>", 2, "sequence value", 52'4', 68'D'} 
  [6] {"<e>", 3, "0", 68'D', 70'F'} 
 
code    : export function test(sequence list, sequence key="default", sequence value=0) 
vars = 
  [1] {"<prefix>", 1, "export", 1, 8} 
  [2] {"<name>", 0, "test", 15, 21} 
  [3] {"<a>", 0, "sequence list", 21, 35'#'} 
  [4] {"<b>", 1, "sequence key", 35'#', 49'1'} 
  [5] {"<c>", 3, "\"default\"", 49'1', 59';'} 
  [6] {"<d>", 2, "sequence value", 59';', 75'K'} 
  [7] {"<e>", 3, "0", 75'K', 77'M'} 

Jean-Marc