more work on parser

backend/src/tokenizer.ts

@@ -52,11 +52,11 @@ export function parseOrderByString(orderBy: string) {
 const openGroupRegex = /\(/
 const closeGroupRegex = /\)/
 const conjunctinoRegex = /AND|OR/
-const statementRegex = /([a-zA-Z]+)\s?(=|!=|<|>|<=|>=|:)\s?([a-zA-Z\d"']+)/
+const equalityRegex = /([a-zA-Z]+)\s?(=|!=|<|>|<=|>=|:)\s?([a-zA-Z\d"']+)/
 const spacerRegex = /\s/
 
 export class FilterParser {
-
+  asty: ASTY = new ASTY()
   lexer: Tokenizr = this.createLexer()
 
   constructor() {}
@@ -76,21 +76,74 @@ export class FilterParser {
       ctx.accept('conjunction', m[0])
     })
 
-    tkz.rule(statementRegex, (ctx, m) => {
+    tkz.rule(equalityRegex, (ctx, m) => {
       ctx.accept('column', m[1])
       ctx.accept('opperator', m[2])
       ctx.accept('value', m[3])
     })
 
-    tkz.rule(spacerRegex, (ctx, m)=> {
-      ctx.ignore();
+    tkz.rule(spacerRegex, (ctx, m) => {
+      ctx.ignore()
     })
 
     return tkz
   }
 
-  buildAST(): ASTY {
-    const ast = new ASTY()
+  parseFilter(filter: string) {
+    this.lexer.input(filter)
+    let block = this.parseBlock()
+    this.lexer.consume('EOF')
+    this.lexer.reset()
+
+    return block
   }
 
+  private parseBlock() {
+    let items = [] 
+
+    for(;;) {
+      let nextItem = this.lexer.alternatives(
+      () => this.parseEquality(),
+      () => this.parseGroup(),
+      () => this.parseConjunction())
+
+      if (nextItem===undefined) {
+        break;
+      }
+
+      items.push(nextItem)
+    }
+    
+    return items
+  }
+
+  private parseConjunction() {
+    
+  }
+
+  private parseEquality() {
+    let columnToken = this.lexer.consume('column')
+    let opperatorToken = this.lexer.consume('opperator')
+    let valueToken = this.lexer.consume('value')
+
+    let node = this.asty.create('equality')
+
+    node.pos(columnToken.line, columnToken.column, columnToken.pos)
+
+    node.set(columnToken.type, columnToken.value)
+    node.set(opperatorToken.type, opperatorToken.value)
+    node.set(valueToken.type, valueToken.value)
+
+    return node
+  }
+
+  private parseGroup() {
+    this.lexer.consume('opengroup')
+    let block = this.parseBlock()
+    this.lexer.consume('closegroup')
+
+    let node = this.asty.create("group").set({ns: ""}).add(block)
+
+    return node
+  }
 }