Simplfy semver handling and share the semver version cache across everything

autoload/ale/handlers/gcc.vim

@@ -18,18 +18,6 @@ function! s:RemoveUnicodeQuotes(text) abort
     return l:text
 endfunction
 
-function! ale#handlers#gcc#ParseGCCVersion(lines) abort
-    for l:line in a:lines
-        let l:match = matchstr(l:line, '\d\.\d\.\d')
-
-        if !empty(l:match)
-            return ale#semver#Parse(l:match)
-        endif
-    endfor
-
-    return []
-endfunction
-
 function! ale#handlers#gcc#HandleGCCFormat(buffer, lines) abort
     " Look for lines like the following.
     "

autoload/ale/semver.vim

@@ -1,27 +1,55 @@
-" Given some text, parse a semantic versioning string from the text
-" into a triple of integeers [major, minor, patch].
+let s:version_cache = {}
+
+" Reset the version cache used for parsing the version.
+function! ale#semver#ResetVersionCache() abort
+    let s:version_cache = {}
+endfunction
+
+" Given an executable name and some lines of output, which can be empty,
+" parse the version from the lines of output, or return the cached version
+" triple [major, minor, patch]
 "
-" If no match can be performed, then an empty List will be returned instead.
-function! ale#semver#Parse(text) abort
-    let l:match = matchlist(a:text, '^ *\(\d\+\)\.\(\d\+\)\.\(\d\+\)')
+" If the version cannot be found, an empty List will be returned instead.
+function! ale#semver#GetVersion(executable, version_lines) abort
+    let l:version = get(s:version_cache, a:executable, [])
 
-    if empty(l:match)
-        return []
-    endif
+    for l:line in a:version_lines
+        let l:match = matchlist(l:line, '\v(\d+)\.(\d+)\.(\d+)')
 
-    return [l:match[1] + 0, l:match[2] + 0, l:match[3] + 0]
+        if !empty(l:match)
+            let l:version = [l:match[1] + 0, l:match[2] + 0, l:match[3] + 0]
+            let s:version_cache[a:executable] = l:version
+
+            break
+        endif
+    endfor
+
+    return l:version
+endfunction
+
+" Return 1 if the semver version has been cached for a given executable.
+function! ale#semver#HasVersion(executable) abort
+    return has_key(s:version_cache, a:executable)
 endfunction
 
 " Given two triples of integers [major, minor, patch], compare the triples
-" and return 1 if the lhs is greater than or equal to the rhs.
-function! ale#semver#GreaterOrEqual(lhs, rhs) abort
+" and return 1 if the LHS is greater than or equal to the RHS.
+"
+" Pairs of [major, minor] can also be used for either argument.
+"
+" 0 will be returned if the LHS is an empty List.
+function! ale#semver#GTE(lhs, rhs) abort
+    if empty(a:lhs)
+        return 0
+    endif
+
     if a:lhs[0] > a:rhs[0]
         return 1
     elseif a:lhs[0] == a:rhs[0]
         if a:lhs[1] > a:rhs[1]
             return 1
         elseif a:lhs[1] == a:rhs[1]
-            return a:lhs[2] >= a:rhs[2]
+            return get(a:lhs, 2) >= get(a:rhs, 2)
         endif
     endif