1 files changed, 72 insertions, 0 deletions
diff --git a/plurals.jison b/plurals.jison
new file mode 100644
index 000000000..9364f994e
--- /dev/null
+++ b/plurals.jison
@@ -0,0 +1,72 @@
+/* description: Parses end executes mathematical expressions. */
+
+/* lexical grammar */
+%lex
+%%
+
+\s+                   /* skip whitespace */
+[0-9]+("."[0-9]+)?\b  return 'NUMBER'
+"n"                   return 'n'
+"||"                  return '||'
+"&&"                  return '&&'
+"?"                   return '?'
+":"                   return ':'
+"<="                  return '<='
+">="                  return '>='
+"<"                   return '<'
+">"                   return '>'
+"!="                  return '!='
+"=="                  return '=='
+"%"                   return '%'
+"("                   return '('
+")"                   return ')'
+<<EOF>>               return 'EOF'
+.                     return 'INVALID'
+
+/lex
+
+/* operator associations and precedence */
+
+%right <code> '?' ':'
+%left '||'
+%left '&&'
+%left '<=' '>=' '<' '>' '!=' '=='
+%left '%'
+
+%start expressions
+
+%% /* language grammar */
+
+expressions
+    : e EOF
+        { return { type : 'GROUP', expr: $1 }; }
+    ;
+
+e
+    : e '?' e ':' e
+        {$$ = { type: 'TERNARY', expr: $1, truthy : $3, falsey: $5 }; }
+    | e '||' e
+        {$$ = { type: "OR", left: $1, right: $3 };}
+    | e '&&' e
+        {$$ = { type: "AND", left: $1, right: $3 };}
+    | e '<' e
+        {$$ = { type: 'LT', left: $1, right: $3 }; }
+    | e '<=' e
+        {$$ = { type: 'LTE', left: $1, right: $3 };}
+    | e '>' e
+        {$$ = { type: 'GT', left: $1, right: $3 };}
+    | e '>=' e
+        {$$ = { type: 'GTE', left: $1, right: $3 };}
+    | e '!=' e
+        {$$ = { type: 'NEQ', left: $1, right: $3 };}
+    | e '==' e
+        {$$ = { type: 'EQ', left: $1, right: $3 };}
+    | e '%' e
+        {$$ = { type: 'MOD', left: $1, right: $3 };}
+    | '(' e ')'
+        {$$ = { type: 'GROUP', expr: $2 }; }
+    | 'n'
+        {$$ = { type: 'VAR' }; }
+    | NUMBER
+        {$$ = { type: 'NUM', val: Number(yytext) }; }
+    ;