.NET Regular Expression to define `if .. then .. else .. endif`

Question

I need two regular expressions to define a section if .. then .. else .. endifand its parts.

From an expression that may be as follows:

Example 1:

5 + 10 * (if (4 + 4.5) > 0 then 20 else 45 endif) + 2

Example 2:

if (20 == 10) then 10 endif

Example 3:

if (20/10 != 2) then (2 * 10) else (3 * 4) endif

Expected Result:

• A regular expression that can give me a part if..endifin the expression Ex. from example 1 i have to get if (4 + 4.5) > 0 then 20 else 45 endifseparately

• A regular expression that can give me parts if..endif. E.g. from example 1 I should get:

Left comparator: (4 + 4.5)
Operator: >
Right comparator: 0
Then Part: 20
ElsePart: 45(can be null or string.Empty)

Note:

• else not required.
• if..endif may be a single expression or may be part of an expression.
• then else .
• , if, >, <, ==, !=, >=, <=
• #.

Answer 1

, if/then/else - (, else); Regex , , / . , . Regex , .

, :

if( *.*? *)then( *.*? *)(?:else( *.*? *))?endif

:

• true
• false ( else )

, if, .

Answer 2

, -, ? , , ANTLR. , , ..