working on parsers

backend/src/tokenizer.ts

@@ -1,4 +1,5 @@
 import Tokenizr from 'tokenizr'
+import ASTY from 'asty'
 
 export const lexr = new Tokenizr()
 
@@ -47,3 +48,49 @@ export function parseOrderByString(orderBy: string) {
   }
   return output
 }
+
+const openGroupRegex = /\(/
+const closeGroupRegex = /\)/
+const conjunctinoRegex = /AND|OR/
+const statementRegex = /([a-zA-Z]+)\s?(=|!=|<|>|<=|>=|:)\s?([a-zA-Z\d"']+)/
+const spacerRegex = /\s/
+
+export class FilterParser {
+
+  lexer: Tokenizr = this.createLexer()
+
+  constructor() {}
+
+  private createLexer(): Tokenizr {
+    const tkz = new Tokenizr()
+
+    tkz.rule(openGroupRegex, (ctx, m) => {
+      ctx.accept('opengroup')
+    })
+
+    tkz.rule(closeGroupRegex, (ctx, m) => {
+      ctx.accept('closegroup')
+    })
+
+    tkz.rule(conjunctinoRegex, (ctx, m) => {
+      ctx.accept('conjunction', m[0])
+    })
+
+    tkz.rule(statementRegex, (ctx, m) => {
+      ctx.accept('column', m[1])
+      ctx.accept('opperator', m[2])
+      ctx.accept('value', m[3])
+    })
+
+    tkz.rule(spacerRegex, (ctx, m)=> {
+      ctx.ignore();
+    })
+
+    return tkz
+  }
+
+  buildAST(): ASTY {
+    const ast = new ASTY()
+  }
+
+}