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Diffstat (limited to 'webapp/non_npm_dependencies/katex/src/buildMathML.js')
| -rw-r--r-- | webapp/non_npm_dependencies/katex/src/buildMathML.js | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/webapp/non_npm_dependencies/katex/src/buildMathML.js b/webapp/non_npm_dependencies/katex/src/buildMathML.js new file mode 100644 index 000000000..f3c7c5e1c --- /dev/null +++ b/webapp/non_npm_dependencies/katex/src/buildMathML.js @@ -0,0 +1,519 @@ +/** + * This file converts a parse tree into a cooresponding MathML tree. The main + * entry point is the `buildMathML` function, which takes a parse tree from the + * parser. + */ + +var buildCommon = require("./buildCommon"); +var fontMetrics = require("./fontMetrics"); +var mathMLTree = require("./mathMLTree"); +var ParseError = require("./ParseError"); +var symbols = require("./symbols"); +var utils = require("./utils"); + +var makeSpan = buildCommon.makeSpan; +var fontMap = buildCommon.fontMap; + +/** + * Takes a symbol and converts it into a MathML text node after performing + * optional replacement from symbols.js. + */ +var makeText = function(text, mode) { + if (symbols[mode][text] && symbols[mode][text].replace) { + text = symbols[mode][text].replace; + } + + return new mathMLTree.TextNode(text); +}; + +/** + * Returns the math variant as a string or null if none is required. + */ +var getVariant = function(group, options) { + var font = options.font; + if (!font) { + return null; + } + + var mode = group.mode; + if (font === "mathit") { + return "italic"; + } + + var value = group.value; + if (utils.contains(["\\imath", "\\jmath"], value)) { + return null; + } + + if (symbols[mode][value] && symbols[mode][value].replace) { + value = symbols[mode][value].replace; + } + + var fontName = fontMap[font].fontName; + if (fontMetrics.getCharacterMetrics(value, fontName)) { + return fontMap[options.font].variant; + } + + return null; +}; + +/** + * Functions for handling the different types of groups found in the parse + * tree. Each function should take a parse group and return a MathML node. + */ +var groupTypes = {}; + +groupTypes.mathord = function(group, options) { + var node = new mathMLTree.MathNode( + "mi", + [makeText(group.value, group.mode)]); + + var variant = getVariant(group, options); + if (variant) { + node.setAttribute("mathvariant", variant); + } + return node; +}; + +groupTypes.textord = function(group, options) { + var text = makeText(group.value, group.mode); + + var variant = getVariant(group, options) || "normal"; + + var node; + if (/[0-9]/.test(group.value)) { + // TODO(kevinb) merge adjacent <mn> nodes + // do it as a post processing step + node = new mathMLTree.MathNode("mn", [text]); + if (options.font) { + node.setAttribute("mathvariant", variant); + } + } else { + node = new mathMLTree.MathNode("mi", [text]); + node.setAttribute("mathvariant", variant); + } + + return node; +}; + +groupTypes.bin = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + return node; +}; + +groupTypes.rel = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + return node; +}; + +groupTypes.open = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + return node; +}; + +groupTypes.close = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + return node; +}; + +groupTypes.inner = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + return node; +}; + +groupTypes.punct = function(group) { + var node = new mathMLTree.MathNode( + "mo", [makeText(group.value, group.mode)]); + + node.setAttribute("separator", "true"); + + return node; +}; + +groupTypes.ordgroup = function(group, options) { + var inner = buildExpression(group.value, options); + + var node = new mathMLTree.MathNode("mrow", inner); + + return node; +}; + +groupTypes.text = function(group, options) { + var inner = buildExpression(group.value.body, options); + + var node = new mathMLTree.MathNode("mtext", inner); + + return node; +}; + +groupTypes.color = function(group, options) { + var inner = buildExpression(group.value.value, options); + + var node = new mathMLTree.MathNode("mstyle", inner); + + node.setAttribute("mathcolor", group.value.color); + + return node; +}; + +groupTypes.supsub = function(group, options) { + var children = [buildGroup(group.value.base, options)]; + + if (group.value.sub) { + children.push(buildGroup(group.value.sub, options)); + } + + if (group.value.sup) { + children.push(buildGroup(group.value.sup, options)); + } + + var nodeType; + if (!group.value.sub) { + nodeType = "msup"; + } else if (!group.value.sup) { + nodeType = "msub"; + } else { + nodeType = "msubsup"; + } + + var node = new mathMLTree.MathNode(nodeType, children); + + return node; +}; + +groupTypes.genfrac = function(group, options) { + var node = new mathMLTree.MathNode( + "mfrac", + [buildGroup(group.value.numer, options), + buildGroup(group.value.denom, options)]); + + if (!group.value.hasBarLine) { + node.setAttribute("linethickness", "0px"); + } + + if (group.value.leftDelim != null || group.value.rightDelim != null) { + var withDelims = []; + + if (group.value.leftDelim != null) { + var leftOp = new mathMLTree.MathNode( + "mo", [new mathMLTree.TextNode(group.value.leftDelim)]); + + leftOp.setAttribute("fence", "true"); + + withDelims.push(leftOp); + } + + withDelims.push(node); + + if (group.value.rightDelim != null) { + var rightOp = new mathMLTree.MathNode( + "mo", [new mathMLTree.TextNode(group.value.rightDelim)]); + + rightOp.setAttribute("fence", "true"); + + withDelims.push(rightOp); + } + + var outerNode = new mathMLTree.MathNode("mrow", withDelims); + + return outerNode; + } + + return node; +}; + +groupTypes.array = function(group, options) { + return new mathMLTree.MathNode( + "mtable", group.value.body.map(function(row) { + return new mathMLTree.MathNode( + "mtr", row.map(function(cell) { + return new mathMLTree.MathNode( + "mtd", [buildGroup(cell, options)]); + })); + })); +}; + +groupTypes.sqrt = function(group, options) { + var node; + if (group.value.index) { + node = new mathMLTree.MathNode( + "mroot", [ + buildGroup(group.value.body, options), + buildGroup(group.value.index, options), + ]); + } else { + node = new mathMLTree.MathNode( + "msqrt", [buildGroup(group.value.body, options)]); + } + + return node; +}; + +groupTypes.leftright = function(group, options) { + var inner = buildExpression(group.value.body, options); + + if (group.value.left !== ".") { + var leftNode = new mathMLTree.MathNode( + "mo", [makeText(group.value.left, group.mode)]); + + leftNode.setAttribute("fence", "true"); + + inner.unshift(leftNode); + } + + if (group.value.right !== ".") { + var rightNode = new mathMLTree.MathNode( + "mo", [makeText(group.value.right, group.mode)]); + + rightNode.setAttribute("fence", "true"); + + inner.push(rightNode); + } + + var outerNode = new mathMLTree.MathNode("mrow", inner); + + return outerNode; +}; + +groupTypes.accent = function(group, options) { + var accentNode = new mathMLTree.MathNode( + "mo", [makeText(group.value.accent, group.mode)]); + + var node = new mathMLTree.MathNode( + "mover", + [buildGroup(group.value.base, options), + accentNode]); + + node.setAttribute("accent", "true"); + + return node; +}; + +groupTypes.spacing = function(group) { + var node; + + if (group.value === "\\ " || group.value === "\\space" || + group.value === " " || group.value === "~") { + node = new mathMLTree.MathNode( + "mtext", [new mathMLTree.TextNode("\u00a0")]); + } else { + node = new mathMLTree.MathNode("mspace"); + + node.setAttribute( + "width", buildCommon.spacingFunctions[group.value].size); + } + + return node; +}; + +groupTypes.op = function(group) { + var node; + + // TODO(emily): handle big operators using the `largeop` attribute + + if (group.value.symbol) { + // This is a symbol. Just add the symbol. + node = new mathMLTree.MathNode( + "mo", [makeText(group.value.body, group.mode)]); + } else { + // This is a text operator. Add all of the characters from the + // operator's name. + // TODO(emily): Add a space in the middle of some of these + // operators, like \limsup. + node = new mathMLTree.MathNode( + "mi", [new mathMLTree.TextNode(group.value.body.slice(1))]); + } + + return node; +}; + +groupTypes.katex = function(group) { + var node = new mathMLTree.MathNode( + "mtext", [new mathMLTree.TextNode("KaTeX")]); + + return node; +}; + +groupTypes.font = function(group, options) { + var font = group.value.font; + return buildGroup(group.value.body, options.withFont(font)); +}; + +groupTypes.delimsizing = function(group) { + var children = []; + + if (group.value.value !== ".") { + children.push(makeText(group.value.value, group.mode)); + } + + var node = new mathMLTree.MathNode("mo", children); + + if (group.value.delimType === "open" || + group.value.delimType === "close") { + // Only some of the delimsizing functions act as fences, and they + // return "open" or "close" delimTypes. + node.setAttribute("fence", "true"); + } else { + // Explicitly disable fencing if it's not a fence, to override the + // defaults. + node.setAttribute("fence", "false"); + } + + return node; +}; + +groupTypes.styling = function(group, options) { + var inner = buildExpression(group.value.value, options); + + var node = new mathMLTree.MathNode("mstyle", inner); + + var styleAttributes = { + "display": ["0", "true"], + "text": ["0", "false"], + "script": ["1", "false"], + "scriptscript": ["2", "false"], + }; + + var attr = styleAttributes[group.value.style]; + + node.setAttribute("scriptlevel", attr[0]); + node.setAttribute("displaystyle", attr[1]); + + return node; +}; + +groupTypes.sizing = function(group, options) { + var inner = buildExpression(group.value.value, options); + + var node = new mathMLTree.MathNode("mstyle", inner); + + // TODO(emily): This doesn't produce the correct size for nested size + // changes, because we don't keep state of what style we're currently + // in, so we can't reset the size to normal before changing it. Now + // that we're passing an options parameter we should be able to fix + // this. + node.setAttribute( + "mathsize", buildCommon.sizingMultiplier[group.value.size] + "em"); + + return node; +}; + +groupTypes.overline = function(group, options) { + var operator = new mathMLTree.MathNode( + "mo", [new mathMLTree.TextNode("\u203e")]); + operator.setAttribute("stretchy", "true"); + + var node = new mathMLTree.MathNode( + "mover", + [buildGroup(group.value.body, options), + operator]); + node.setAttribute("accent", "true"); + + return node; +}; + +groupTypes.rule = function(group) { + // TODO(emily): Figure out if there's an actual way to draw black boxes + // in MathML. + var node = new mathMLTree.MathNode("mrow"); + + return node; +}; + +groupTypes.llap = function(group, options) { + var node = new mathMLTree.MathNode( + "mpadded", [buildGroup(group.value.body, options)]); + + node.setAttribute("lspace", "-1width"); + node.setAttribute("width", "0px"); + + return node; +}; + +groupTypes.rlap = function(group, options) { + var node = new mathMLTree.MathNode( + "mpadded", [buildGroup(group.value.body, options)]); + + node.setAttribute("width", "0px"); + + return node; +}; + +groupTypes.phantom = function(group, options, prev) { + var inner = buildExpression(group.value.value, options); + return new mathMLTree.MathNode("mphantom", inner); +}; + +/** + * Takes a list of nodes, builds them, and returns a list of the generated + * MathML nodes. A little simpler than the HTML version because we don't do any + * previous-node handling. + */ +var buildExpression = function(expression, options) { + var groups = []; + for (var i = 0; i < expression.length; i++) { + var group = expression[i]; + groups.push(buildGroup(group, options)); + } + return groups; +}; + +/** + * Takes a group from the parser and calls the appropriate groupTypes function + * on it to produce a MathML node. + */ +var buildGroup = function(group, options) { + if (!group) { + return new mathMLTree.MathNode("mrow"); + } + + if (groupTypes[group.type]) { + // Call the groupTypes function + return groupTypes[group.type](group, options); + } else { + throw new ParseError( + "Got group of unknown type: '" + group.type + "'"); + } +}; + +/** + * Takes a full parse tree and settings and builds a MathML representation of + * it. In particular, we put the elements from building the parse tree into a + * <semantics> tag so we can also include that TeX source as an annotation. + * + * Note that we actually return a domTree element with a `<math>` inside it so + * we can do appropriate styling. + */ +var buildMathML = function(tree, texExpression, options) { + var expression = buildExpression(tree, options); + + // Wrap up the expression in an mrow so it is presented in the semantics + // tag correctly. + var wrapper = new mathMLTree.MathNode("mrow", expression); + + // Build a TeX annotation of the source + var annotation = new mathMLTree.MathNode( + "annotation", [new mathMLTree.TextNode(texExpression)]); + + annotation.setAttribute("encoding", "application/x-tex"); + + var semantics = new mathMLTree.MathNode( + "semantics", [wrapper, annotation]); + + var math = new mathMLTree.MathNode("math", [semantics]); + + // You can't style <math> nodes, so we wrap the node in a span. + return makeSpan(["katex-mathml"], [math]); +}; + +module.exports = buildMathML; |