3 files changed, 31 insertions, 20 deletions
diff --git a/autoload/polyglot/detect.vim b/autoload/polyglot/detect.vim
index b1b5d6d7..cac826cf 100644
--- a/autoload/polyglot/detect.vim
+++ b/autoload/polyglot/detect.vim
@@ -53,16 +53,16 @@ func! polyglot#detect#H(...)
   for lnum in range(1, min([line("$"), 200]))
     let line = getline(lnum)
     if line =~# '^\s*\(@\(interface\|class\|protocol\|property\|end\|synchronised\|selector\|implementation\)\(\<\|\>\)\|#import\s\+.\+\.h[">]\)'
-      if exists("g:c_syntax_for_h")
+      if exists('g:c_syntax_for_h')
         set ft=objc | return
       endif
       set ft=objcpp | return
     endif
   endfor
-  if exists("g:c_syntax_for_h")
+  if exists('g:c_syntax_for_h')
     set ft=c | return
   endif
-  if exists("g:ch_syntax_for_h")
+  if exists('g:ch_syntax_for_h')
     set ft=ch | return
   endif
   set ft=cpp | return
@@ -82,7 +82,14 @@ func! polyglot#detect#M(...)
       set ft=objc | return
     endif
     if line =~# '^\s*%'
-      set ft=octave | return
+      if !has_key(g:polyglot_is_disabled, 'octave')
+        set ft=octave | return
+      endif
+    endif
+    if line =~# '^\s*%'
+      if has_key(g:polyglot_is_disabled, 'octave')
+        set ft=matlab | return
+      endif
     endif
     if line =~# '^\s*(\*'
       set ft=mma | return
@@ -97,7 +104,12 @@ func! polyglot#detect#M(...)
   if exists("g:filetype_m")
     let &ft = g:filetype_m | return
   endif
-  set ft=octave | return
+  if !has_key(g:polyglot_is_disabled, 'octave')
+    set ft=octave | return
+  endif
+  if has_key(g:polyglot_is_disabled, 'octave')
+    set ft=matlab | return
+  endif
 endfunc
 
 func! polyglot#detect#Fs(...)
diff --git a/heuristics.yaml b/heuristics.yaml
index 23f63bb4..fd7fbe94 100644
--- a/heuristics.yaml
+++ b/heuristics.yaml
@@ -28,12 +28,12 @@ rules:
 - lines: 200
   pattern: '^\s*(@(interface|class|protocol|property|end|synchronised|selector|implementation)\b|#import\s+.+\.h[">])'
   rules:
-  - if_exists: "g:c_syntax_for_h"
+  - if: "exists('g:c_syntax_for_h')"
     filetype: objc
   - filetype: objcpp
-- if_exists: "g:c_syntax_for_h"
+- if: "exists('g:c_syntax_for_h')"
   filetype: c
-- if_exists: "g:ch_syntax_for_h"
+- if: "exists('g:ch_syntax_for_h')"
   filetype: ch
 - filetype: cpp
 ---
@@ -46,16 +46,23 @@ rules:
   - pattern: '^\s*(@(interface|class|protocol|property|end|synchronised|selector|implementation)\b|#import\s+.+\.h[">])'
     filetype: objc
   - pattern: '^\s*%'
+    if: "!has_key(g:polyglot_is_disabled, 'octave')"
     filetype: octave
+  - pattern: '^\s*%'
+    if: "has_key(g:polyglot_is_disabled, 'octave')"
+    filetype: matlab
   - pattern: '^\s*\(\*'
     filetype: mma
   - pattern: '^\s*((type|var)\b|--)'
     ignore_case: true
     filetype: murphi
-- if_set: "saw_comment"
+- if: "saw_comment"
   filetype: objc
 - override: true
 - filetype: octave
+  if: "!has_key(g:polyglot_is_disabled, 'octave')"
+- filetype: matlab
+  if: "has_key(g:polyglot_is_disabled, 'octave')"
 ---
 extensions: [fs]
 rules:
diff --git a/scripts/build b/scripts/build
index 7d278a8a..77d71cdd 100755
--- a/scripts/build
+++ b/scripts/build
@@ -427,18 +427,10 @@ def rule_to_code(rule)
     end.join("\n")
   end
 
-  if rule.has_key?("if_set")
+  if rule.has_key?("if")
     return <<~EOS
-      if #{rule["negative"] ? "!" : ""}#{rule["if_set"]}
-      #{indent(rule_to_code(except(rule, "if_set", "negative")), 2)}
-      endif
-    EOS
-  end
-
-  if rule.has_key?("if_exists")
-    return <<~EOS
-      if #{rule["negative"] ? "!" : ""}exists("#{rule["if_exists"]}")
-      #{indent(rule_to_code(except(rule, "if_exists", "negative")), 2)}
+      if #{rule["if"]}
+      #{indent(rule_to_code(except(rule, "if")), 2)}
       endif
     EOS
   end