Add support for the \text command.

Adds support for #12.

Author: kostub

iosMath/lib/MTMathAtomFactory.m

@@ -868,6 +868,7 @@ + (NSDictionary*) delimValueToName
                        @"mathbb": @(kMTFontStyleBlackboard),
                        @"mathbfit": @(kMTFontStyleBoldItalic),
                        @"bm": @(kMTFontStyleBoldItalic),
+                       @"text": @(kMTFontStyleRoman),
                    };
     }
     return fontStyles;

iosMath/lib/MTMathListBuilder.m

@@ -44,6 +44,7 @@ @implementation MTMathListBuilder {
     MTInner* _currentInnerAtom;
     MTEnvProperties* _currentEnv;
     MTFontStyle _currentFontStyle;
+    BOOL _spacesAllowed;
 }
 
 - (instancetype)initWithString:(NSString *)str
@@ -181,13 +182,18 @@ - (MTMathList*)buildInternal:(BOOL) oneCharOnly stopChar:(unichar) stop
             }
             MTFontStyle fontStyle = [MTMathAtomFactory fontStyleWithName:command];
             if (fontStyle != NSNotFound) {
+                BOOL oldSpacesAllowed = _spacesAllowed;
+                // Text has special consideration where it allows spaces without escaping.
+                _spacesAllowed = [command isEqualToString:@"text"];
                 MTFontStyle oldFontStyle = _currentFontStyle;
                 _currentFontStyle = fontStyle;
                 MTMathList* sublist = [self buildInternal:true];
-                prevAtom = [sublist.atoms lastObject];
-                [list append:sublist];
                 // Restore the font style.
                 _currentFontStyle = oldFontStyle;
+                _spacesAllowed = oldSpacesAllowed;
+
+                prevAtom = [sublist.atoms lastObject];
+                [list append:sublist];
                 if (oneCharOnly) {
                     return list;
                 }
@@ -212,6 +218,9 @@ - (MTMathList*)buildInternal:(BOOL) oneCharOnly stopChar:(unichar) stop
                 MTMathAtom* table = [self buildTable:nil firstList:list row:NO];
                 return [MTMathList mathListWithAtoms:table, nil];
             }
+        } else if (_spacesAllowed && ch == ' ') {
+            // If spaces are allowed then spaces do not need escaping with a \ before being used.
+            atom = [MTMathAtomFactory atomForLatexSymbolName:@" "];
         } else {
             atom = [MTMathAtomFactory atomForCharacter:ch];
             if (!atom) {

iosMath/render/internal/MTTypesetter.m

@@ -217,7 +217,9 @@ UTF32Char getDefaultStyle(unichar ch) {
 }
 
 static const UTF32Char kMTUnicodeMathCapitalScriptStart = 0x1D49C;
-static const UTF32Char kMTUnicodeMathLowerScriptStart = 0x1D4B6;
+// TODO(kostub): Unused in Latin Modern Math - if another font is used determine if
+// this should be applicable.
+// static const UTF32Char kMTUnicodeMathLowerScriptStart = 0x1D4B6;
 
 // mathcal/mathscr (caligraphic or script)
 UTF32Char getCaligraphic(unichar ch) {
@@ -252,8 +254,9 @@ UTF32Char getCaligraphic(unichar ch) {
     if (IS_UPPER_EN(ch)) {
         unicode = kMTUnicodeMathCapitalScriptStart + (ch - 'A');
     } else if (IS_LOWER_EN(ch)) {
-        // TODO:(kostub) Latin Modern Math does not have lower case caligraphic characters.
-        unicode = kMTUnicodeMathLowerScriptStart + (ch - 'a');
+        // Latin Modern Math does not have lower case caligraphic characters, so we use
+        // the default style instead of showing a ?
+        unicode = getDefaultStyle(ch);
     } else {
         // Caligraphic characters don't exist for greek or numbers, we give them the
         // default treatment.

iosMathExample/example/ViewController.m

@@ -308,8 +308,9 @@ - (void)viewDidLoad
                            "\\end{bmatrix}"
                                      withHeight:120];
     self.labels[42] = [self createMathLabel:@"x{\\scriptstyle y}z" withHeight:30];
-    self.labels[43] = [self createMathLabel:@"x \\mathrm x \\mathbf x \\mathcal X \\mathfrak x \\mathsf x \\bm x \\mathtt x \\mathit \\Lambda" withHeight:30];
-    self.labels[44] = [self createMathLabel:@"\\mathrm{different\\ text}" withHeight:30];
+    self.labels[43] = [self createMathLabel:@"x \\mathrm x \\mathbf x \\mathcal X \\mathfrak x \\mathsf x \\bm x \\mathtt x \\mathit \\Lambda \\cal g" withHeight:30];
+    self.labels[44] = [self createMathLabel:@"\\mathrm{using\\ mathrm}" withHeight:30];
+    self.labels[45] = [self createMathLabel:@"\\text{using text}" withHeight:30];
 
     for (NSUInteger i = 1; i < self.labels.count; i++) {
         [self addLabelWithIndex:i inArray:self.labels toView:contentView];

iosMathTests/MTMathListBuilderTest.m

@@ -1240,25 +1240,25 @@ - (void) testFontOneChar
 
 - (void) testFontMultipleChars
 {
-    NSString *str = @"\\frak{AB}";
+    NSString *str = @"\\frak{xy}";
     MTMathList* list = [MTMathListBuilder buildFromString:str];
     NSString* desc = [NSString stringWithFormat:@"Error for string:%@", str];
 
     XCTAssertNotNil(list, @"%@", desc);
     XCTAssertEqualObjects(@(list.atoms.count), @2, @"%@", desc);
     MTMathAtom* atom = list.atoms[0];
     XCTAssertEqual(atom.type, kMTMathAtomVariable, @"%@", desc);
-    XCTAssertEqualObjects(atom.nucleus, @"A", @"%@", desc);
+    XCTAssertEqualObjects(atom.nucleus, @"x", @"%@", desc);
     XCTAssertEqual(atom.fontStyle, kMTFontStyleFraktur);
 
     atom = list.atoms[1];
     XCTAssertEqual(atom.type, kMTMathAtomVariable, @"%@", desc);
-    XCTAssertEqualObjects(atom.nucleus, @"B", @"%@", desc);
+    XCTAssertEqualObjects(atom.nucleus, @"y", @"%@", desc);
     XCTAssertEqual(atom.fontStyle, kMTFontStyleFraktur);
 
     // convert it back to latex
     NSString* latex = [MTMathListBuilder mathListToString:list];
-    XCTAssertEqualObjects(latex, @"\\mathfrak{AB}", @"%@", desc);
+    XCTAssertEqualObjects(latex, @"\\mathfrak{xy}", @"%@", desc);
 }
 
 - (void) testFontOneCharInside
@@ -1289,4 +1289,32 @@ - (void) testFontOneCharInside
     NSString* latex = [MTMathListBuilder mathListToString:list];
     XCTAssertEqualObjects(latex, @"\\sqrt{\\mathrm{x}}y", @"%@", desc);
 }
+
+- (void) testText
+{
+    NSString *str = @"\\text{x y}";
+    MTMathList* list = [MTMathListBuilder buildFromString:str];
+    NSString* desc = [NSString stringWithFormat:@"Error for string:%@", str];
+
+    XCTAssertNotNil(list, @"%@", desc);
+    XCTAssertEqualObjects(@(list.atoms.count), @3, @"%@", desc);
+    MTMathAtom* atom = list.atoms[0];
+    XCTAssertEqual(atom.type, kMTMathAtomVariable, @"%@", desc);
+    XCTAssertEqualObjects(atom.nucleus, @"x", @"%@", desc);
+    XCTAssertEqual(atom.fontStyle, kMTFontStyleRoman);
+
+    atom = list.atoms[1];
+    XCTAssertEqual(atom.type, kMTMathAtomOrdinary, @"%@", desc);
+    XCTAssertEqualObjects(atom.nucleus, @" ", @"%@", desc);
+
+    atom = list.atoms[2];
+    XCTAssertEqual(atom.type, kMTMathAtomVariable, @"%@", desc);
+    XCTAssertEqualObjects(atom.nucleus, @"y", @"%@", desc);
+    XCTAssertEqual(atom.fontStyle, kMTFontStyleRoman);
+
+
+    // convert it back to latex
+    NSString* latex = [MTMathListBuilder mathListToString:list];
+    XCTAssertEqualObjects(latex, @"\\mathrm{x\\  y}", @"%@", desc);
+}
 @end