italic && bold declarative

index.js

@@ -0,0 +1,114 @@
+/*
+ * md ast - pluggable markdown parser
+ */
+
+
+const syntax = {
+    bold: {
+        paired: true,
+        recursive: true,
+        startRegexp: /\s\*\*\S.*/,
+        endRegexp:   /\S\*\*\s/,
+        content: {
+            start: {
+                point: 'start',
+                offset: 3
+            },
+            end: {
+                point: 'end',
+                offset: 1
+            }
+        },
+        forward: {
+            point: 'endEnd', //start, startEnd, end, endEnd
+            offset: -1
+        }
+    },
+    bold2: {
+        paired: true,
+        recursive: true,
+        startRegexp:  /__\S.*/,
+        endRegexp:    /\S__\s/,
+        content: {
+            start: {
+                point: 'start',
+                offset: 3
+            },
+            end: {
+                point: 'end',
+                offset: 1
+            }
+        },
+        forward: {
+            point: 'endEnd', //start, startEnd, end, endEnd
+            offset: -1
+        }
+    },
+    italic: {
+        paired: true,
+        recursive: true,
+        startRegexp: /\s\*\S.*/,
+        endRegexp:   /\S\*\s/,
+        content: {
+            start: {
+                point: 'start',
+                offset: 2
+            },
+            end: {
+                point: 'end',
+                offset: 1
+            }
+        },
+        forward: {
+            point: 'endEnd', //start, startEnd, end, endEnd
+            offset: -1
+        }
+    },
+    italic2: {
+        paired: true,
+        recursive: true,
+        startRegexp:  /_\S.*/,
+        endRegexp:   /\S_\s/,
+        content: {
+            start: {
+                point: 'start',
+                offset: 2
+            },
+            end: {
+                point: 'end',
+                offset: 1
+            }
+        },
+        forward: {
+            point: 'endEnd', //start, startEnd, end, endEnd
+            offset: -1
+        }
+    },
+}
+
+function findNearest(md, mdTags){
+    let nearest, nearestMatch = {index: Infinity};
+    for (let [mdTag, {paired, 
+                        recursive, 
+                        startRegexp, 
+                        endRegexp, 
+                        content: {start, 
+                                    end}, 
+                        forward}] of  Object.entries(mdTags)) {
+
+        let match = md.match(startRegexp)
+        if (match && match.index < nearestMatch.index){
+            nearestMatch = match
+            nearest = mdTag
+        }
+    }
+    return [nearest, nearestMatch]
+}
+
+
+function buildAST(md, mdTags=syntax, tree=[], path=[]){
+    console.log(findNearest(md, mdTags))
+}
+
+buildAST("I just __love__ __bold text__.	")
+