Added function for finding the first substring/character in a string.

Author: LarsAsplund

setup.py

@@ -30,7 +30,7 @@ def find_all_files(directory, endings=None):
 
 setup(
     name='vunit_hdl',
-    version='0.47.0',
+    version='0.48.0',
     packages=['vunit',
               'vunit.com',
               'vunit.test',

vunit/vhdl/string_ops/src/string_ops.vhd

@@ -27,6 +27,18 @@ package string_ops is
     constant start : natural := 0;
     constant stop : natural := 0)
     return natural;
+  function find (
+    constant s : string;
+    constant substring : string;
+    constant start : natural := 0;
+    constant stop : natural := 0)
+    return natural;
+  function find (
+    constant s : string;
+    constant char : character;
+    constant start : natural := 0;
+    constant stop : natural := 0)
+    return natural;
   function strip (
     str : string;
     chars : string := " ")
@@ -116,16 +128,48 @@ package body string_ops is
     end if;
   end function offset;
 
-  function in_range (
+  function index (
+    constant s     : string;
+    constant offset : natural)
+    return positive is
+  begin
+    if s'ascending then
+      return s'left + offset;
+    else
+      return s'left - offset;
+    end if;
+  end function index;
+
+  function left_of_range (
     constant s     : string;
     constant index : natural)
     return boolean is
   begin
     if s'ascending then
-      return (index >= s'left) and (index <= s'right);
+      return (index < s'left);
     else
-      return (index <= s'left) and (index >= s'right);
+      return (index > s'left);
     end if;
+  end function left_of_range;
+
+  function right_of_range (
+    constant s     : string;
+    constant index : natural)
+    return boolean is
+  begin
+    if s'ascending then
+      return (index > s'right);
+    else
+      return (index < s'right);
+    end if;
+  end function right_of_range;
+
+  function in_range (
+    constant s     : string;
+    constant index : natural)
+    return boolean is
+  begin
+    return not left_of_range(s, index) and not right_of_range(s, index);
   end function in_range;
 
   function slice (
@@ -448,6 +492,60 @@ package body string_ops is
     return n;
   end count;
 
+  function find (
+    constant s : string;
+    constant char : character;
+    constant start : natural := 0;
+    constant stop : natural := 0)
+    return natural is
+    variable substring : string(1 to 1);
+  begin
+    substring(1) := char;
+    return find(s, substring, start, stop);
+  end;
+
+  function find (
+    constant s : string;
+    constant substring : string;
+    constant start : natural := 0;
+    constant stop : natural := 0)
+    return natural is
+    variable start_pos, stop_pos : natural;
+    variable o : natural;
+  begin
+    if start = 0 or left_of_range(s, start) then
+      start_pos := s'left;
+    elsif right_of_range(s, start) then
+      return 0;
+    else
+      start_pos := start;
+    end if;
+
+    if stop = 0 or right_of_range(s, stop) then
+      stop_pos := s'right;
+    elsif left_of_range(s, stop) then
+      return 0;
+    else
+      stop_pos := stop;
+    end if;
+
+    if substring = "" then
+      return start_pos;
+    end if;
+
+    o := offset(s, start_pos);
+    while o <= offset(s, stop_pos) - substring'length + 1 loop
+      if slice(s, o, substring'length) = substring then
+        return index(s, o);
+      end if;
+
+      o := o + 1;
+    end loop;
+
+    return 0;
+
+  end find;
+
   impure function split (
     constant s         : string;
     constant sep       : string;

vunit/vhdl/string_ops/test/tb_string_ops.vhd

@@ -130,6 +130,46 @@ begin
         counting_assert(count(reverse_string, "a", 12 ,4) = 0, "Should not find anything outside of the string");
         counting_assert(count("aba", "a", 3 ,1) = 0, "Should not find anything within a negative range");
         counting_assert(count("aba", "abab") = 0, "Should not find anything when substring is longer than the string");
+      elsif run("Test find") then
+        counting_assert(find("", "") = 1, "Empty string should be found at the start");
+        counting_assert(find("foo bar", "") = 1, "Empty string should be found at the start");
+        counting_assert(find("foo bar", "foo") = 1, "Should find string at the start");
+        counting_assert(find("foo bar", "bar") = 5, "Should find string at the end");
+        counting_assert(find("foo bar", "o b") = 3, "Should find string in the middle");
+        counting_assert(find("foo bar", "foo bar") = 1, "Should find full string");
+        counting_assert(find("foo bar", 'f') = 1, "Should find character at the start");
+        counting_assert(find("foo bar", 'r') = 7, "Should find character at the end");
+        counting_assert(find("foo bar", ' ') = 4, "Should find character in the middle");
+        counting_assert(find("foo bar", "bars") = 0, "Should return 0 when string not found");
+        counting_assert(find("foo bar", "foo bars") = 0, "Should return 0 when string not found");
+        counting_assert(find("foo bar", 'q') = 0, "Should return 0 when character not found");
+        counting_assert(find(offset_string, "") = 10, "Empty string should be found at the start on offset string");
+        counting_assert(find(offset_string, "foo") = 10, "Should find string at the start on offset string");
+        counting_assert(find(offset_string, "bar") = 14, "Should find string at the end on offset string");
+        counting_assert(find(offset_string, "o b") = 12, "Should find string in the middle on offset string");
+        counting_assert(find(reverse_string, "") = 16, "Empty string should be found at the start on reversed string");
+        counting_assert(find(reverse_string, "foo") = 16, "Should find string at the start on reversed string");
+        counting_assert(find(reverse_string, "bar") = 12, "Should find string at the end on reversed string");
+        counting_assert(find(reverse_string, "o b") = 14, "Should find string in the middle on reversed string");
+        counting_assert(find("foo bar", "oo", 2, 6) = 2, "Should find string at the start of slice");
+        counting_assert(find("foo bar", "ba", 2, 6) = 5, "Should find string at the end of slice");
+        counting_assert(find("foo bar", "o b", 2, 6) = 3, "Should find string in the middle of slice");
+        counting_assert(find("foo bar", "", 2, 6) = 2, "Empty string should be found at the start of slice");
+        counting_assert(find("foo bar", 'f', 2, 6) = 0, "Should not find anything before slice");
+        counting_assert(find("foo bar", "ar", 2, 6) = 0, "Should not find anything after slice");
+        counting_assert(find(offset_string, 'f', 11, 15) = 0, "Should not find anything before slice in offset string");
+        counting_assert(find(offset_string, "ar", 11, 15) = 0, "Should not find anything after slice in offset string");
+        counting_assert(find(reverse_string, 'f', 15, 11) = 0, "Should not find anything before slice in reversed string");
+        counting_assert(find(reverse_string, "ar", 15, 11) = 0, "Should not find anything after slice in reversed string");
+        counting_assert(find("foo bar", "o b", 1, 100) = 3, "Should find in ranges wider than input'range");
+        counting_assert(find("foo bar", "zen", 1, 100) = 0, "Should not find in ranges wider than input'range");
+        counting_assert(find(offset_string, "o b", 1, 100) = 12, "Should find in ranges wider than input'range");
+        counting_assert(find(offset_string, "zen", 1, 100) = 0, "Should not find in ranges wider than input'range");
+        counting_assert(find(reverse_string, "o b", 100, 1) = 14, "Should find in ranges wider than input'range");
+        counting_assert(find(reverse_string, "zen", 100, 1) = 0, "Should not find in ranges wider than input'range");
+        counting_assert(find("foo bar", "o b", 3, 2) = 0, "Should not find string in negative range");
+        counting_assert(find("foo bar", "o b", 30, 0) = 0, "Should not find string in negative range");
+        counting_assert(find(reverse_string, "o b", 1, 100) = 0, "Should not find string in negative range");
 
       elsif run("Test image") then
         counting_assert(image("") = "", "Should return empty string on empty input vector.");