Parsing for style commands.

iosMath/lib/MTMathAtomFactory.m

@@ -494,6 +494,12 @@ + (MTFraction *)fractionWithNumeratorStr:(NSString *)numStr denominatorStr:(NSSt
                      @"!" : [[MTMathSpace alloc] initWithSpace:-3],
                      @"quad" : [[MTMathSpace alloc] initWithSpace:18],  // quad = 1em = 18mu
                      @"qquad" : [[MTMathSpace alloc] initWithSpace:36], // qquad = 2em
+
+                     // Style
+                     @"displaystyle" : [[MTMathStyle alloc] initWithStyle:kMTLineStyleDisplay],
+                     @"textstyle" : [[MTMathStyle alloc] initWithStyle:kMTLineStyleText],
+                     @"scriptstyle" : [[MTMathStyle alloc] initWithStyle:kMTLineStyleScript],
+                     @"scriptscriptstyle" : [[MTMathStyle alloc] initWithStyle:kMTLineStyleScriptScript],
                      };
 
     }

iosMath/lib/MTMathListBuilder.m

@@ -401,6 +401,20 @@ + (NSDictionary*) spaceToCommands
     return spaceToCommands;
 }
 
++ (NSDictionary*) styleToCommands
+{
+    static NSDictionary* styleToCommands = nil;
+    if (!styleToCommands) {
+        styleToCommands = @{
+                            @(kMTLineStyleDisplay) : @"displaystyle",
+                            @(kMTLineStyleText) : @"textstyle",
+                            @(kMTLineStyleScript) : @"scriptstyle",
+                            @(kMTLineStyleScriptScript) : @"scriptscriptstyle",
+                            };
+    }
+    return styleToCommands;
+}
+
 + (MTMathList *)buildFromString:(NSString *)str
 {
     MTMathListBuilder* builder = [[MTMathListBuilder alloc] initWithString:str];
@@ -503,6 +517,11 @@ + (NSString *)mathListToString:(MTMathList *)ml
             } else {
                 [str appendFormat:@"\\mkern%.1fmu", space.space];
             }
+        } else if (atom.type == kMTMathAtomStyle) {
+            MTMathStyle* style = (MTMathStyle*) atom;
+            NSDictionary* styleToCommands = [MTMathListBuilder styleToCommands];
+            NSString* command = styleToCommands[@(style.style)];
+            [str appendFormat:@"\\%@ ", command];
         } else if (atom.nucleus.length == 0) {
             [str appendString:@"{}"];
         } else if ([atom.nucleus isEqualToString:@"\u2236"]) {

iosMathTests/MTMathListBuilderTest.m

@@ -875,6 +875,29 @@ - (void) testMathSpace
     XCTAssertEqualObjects(latex, @"\\! ", @"%@", desc);
 }
 
+- (void) testMathStyle
+{
+    NSString *str = @"\\textstyle y \\scriptstyle x";
+    MTMathList* list = [MTMathListBuilder buildFromString:str];
+    NSString* desc = [NSString stringWithFormat:@"Error for string:%@", str];
+
+    XCTAssertNotNil(list, @"%@", desc);
+    XCTAssertEqualObjects(@(list.atoms.count), @4, @"%@", desc);
+    MTMathStyle* style = list.atoms[0];
+    XCTAssertEqual(style.type, kMTMathAtomStyle, @"%@", desc);
+    XCTAssertEqualObjects(style.nucleus, @"", @"%@", desc);
+    XCTAssertEqual(style.style, kMTLineStyleText);
+
+    MTMathStyle* style2 = list.atoms[2];
+    XCTAssertEqual(style2.type, kMTMathAtomStyle, @"%@", desc);
+    XCTAssertEqualObjects(style2.nucleus, @"", @"%@", desc);
+    XCTAssertEqual(style2.style, kMTLineStyleScript);
+
+    // convert it back to latex
+    NSString* latex = [MTMathListBuilder mathListToString:list];
+    XCTAssertEqualObjects(latex, @"\\textstyle y\\scriptstyle x", @"%@", desc);
+}
+
 static NSArray* getTestDataParseErrors() {
     return @[
               @[@"}a", @(MTParseErrorMismatchBraces)],

iosMathTests/MTTypesetterTest.m

@@ -1288,8 +1288,8 @@ - (void) testLatexSymbols
         MTMathList* list = [[MTMathList alloc] init];
         MTMathAtom* atom = [MTMathAtomFactory atomForLatexSymbolName:symName];
         XCTAssertNotNil(atom);
-        if (atom.type == kMTMathAtomSpace) {
-            // Skip spaces as they don't get rendered.
+        if (atom.type >= kMTMathAtomBoundary) {
+            // Skip these types as they aren't symbols.
             continue;
         }