From 3854a42db888a58f0452bfb23b6e17df5bf8ad39 Mon Sep 17 00:00:00 2001
From: Akshay Nair <phenax5@gmail.com>
Date: Thu, 10 Aug 2023 21:27:42 +0530
Subject: feat: multi expression parser done

---
 src/parse-expr.ts | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

(limited to 'src/parse-expr.ts')

diff --git a/src/parse-expr.ts b/src/parse-expr.ts
index dbad1a1..ec387d6 100644
--- a/src/parse-expr.ts
+++ b/src/parse-expr.ts
@@ -5,6 +5,7 @@ export type Expr = Enum<{
   Call: { name: string, args: Expr[] }
   Var: { name: string, defaultValue: Expr }
   Identifier: string
+  Chain: { exprs: Expr[] }
   LiteralString: string
 }>
 
@@ -12,24 +13,33 @@ export const Expr = constructors<Expr>()
 
 const whitespace = P.regex(/\s*/)
 const consumeWhitespace = <A>(p: P.Parser<A>): P.Parser<A> => P.between(whitespace, p, whitespace)
+const comma = consumeWhitespace(P.string(','))
+const parens = <A>(p: P.Parser<A>): P.Parser<A> => P.between(P.string('('), p, P.string(')'))
+const identifierParser = P.regex(/^[a-z][a-z0-9_-]*/i)
 
-const identifierParser = P.regex(/^[a-z][a-z0-9]+/i)
 const identifierExprParser = P.map(identifierParser, ident => Expr.Identifier(ident))
 
-const callParser = P.map(P.zip2(
+const callExprParser = (input: string) => P.map(P.zip2(
   consumeWhitespace(identifierParser),
-  P.between(P.string('('), consumeWhitespace(identifierParser), P.string(')')),
-), ([name, rest]) => Expr.Call({ name, args: [Expr.Identifier(rest)] }))
+  parens(consumeWhitespace(P.sepBy(exprParser, comma))),
+), ([name, args]) => Expr.Call({ name, args }))(input)
 
 const exprParser: P.Parser<Expr> = P.or([
-  callParser,
+  callExprParser,
   identifierExprParser,
 ])
 
-export const parse = (input: string): Expr => {
-  const res = exprParser(input.trim());
+const multiExpr = P.many1(exprParser)
+
+export const parse = (input: string): Array<Expr> => {
+  const res = multiExpr(input.trim());
   return match(res, {
-    Ok: ({ value }) => value,
+    Ok: ({ value, input }) => {
+      if (input) {
+        throw new Error(`Input not consumed completely here brosky: "${input}"`) 
+      }
+      return value
+    },
     Err: ({ error, input }) => {
       throw new Error(`${error}.\n Left input: ${input.slice(0, 20)}...`)
     },
-- 
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