From 6e2349e875e77d8af8b7d6f00f718db6813b40c1 Mon Sep 17 00:00:00 2001
From: Marc Vertes <mvertes@free.fr>
Date: Fri, 3 Nov 2023 19:05:14 +0100
Subject: feat: add support for control flow operators in expressions

Logical operators `&&` (and), `||` (or) are now parsed in expressions.
The control flow tokens (labels, conditional jumps) are added
accordingly.
---
 parser/parse.go | 110 --------------------------------------------------------
 1 file changed, 110 deletions(-)

(limited to 'parser/parse.go')

diff --git a/parser/parse.go b/parser/parse.go
index 757468c..fb8ae2c 100644
--- a/parser/parse.go
+++ b/parser/parse.go
@@ -441,116 +441,6 @@ func (p *Parser) ParseReturn(in Tokens) (out Tokens, err error) {
 	return out, err
 }
 
-func (p *Parser) ParseExpr(in Tokens) (out Tokens, err error) {
-	log.Println("ParseExpr in:", in)
-	var ops Tokens
-	var vl int
-	//
-	// Process tokens from last to first, the goal is to reorder the tokens in
-	// a stack machine processing order, so it can be directly interpreted.
-	//
-	for i := len(in) - 1; i >= 0; i-- {
-		t := in[i]
-		// temporary assumptions: binary operators, returning 1 value
-		switch t.Id {
-		case lang.Ident:
-			// resolve symbol if not a selector rhs.
-			// TODO: test for selector expr.
-			_, sc, ok := p.getSym(t.Str, p.scope)
-			if ok && sc != "" {
-				t.Str = sc + "/" + t.Str
-			}
-			out = append(out, t)
-			vl++
-		case lang.Int, lang.String:
-			out = append(out, t)
-			vl++
-		case lang.Define, lang.Add, lang.Sub, lang.Assign, lang.Equal, lang.Greater, lang.Less, lang.Mul:
-			// TODO: handle operator precedence to swap operators / operands if necessary
-			if vl < 2 {
-				ops = append(ops, t)
-				break
-			}
-		case lang.ParenBlock:
-			// If the previous token is an arithmetic, logic or assign operator then
-			// this parenthesis block is an enclosed expr, otherwise a call expr.
-			if i == 0 || in[i-1].Id.IsOperator() {
-				out = append(out, t)
-				vl++
-				break
-			}
-			// The call expression can be a function call, a conversion,
-			// a type assersion (including for type switch)
-			// func call: push args and func address then call
-			out = append(out, t)
-			vl++
-			if t2 := in[i-1]; t2.Id == lang.Ident {
-				if s, sc, ok := p.getSym(t2.Str, p.scope); ok {
-					log.Println("callExpr:", t2.Str, p.scope, s, ok, sc)
-					if s.kind == symValue {
-						// Store the number of input parameters in the token Beg field.
-						ops = append(ops, scanner.Token{Str: "callX", Id: lang.CallX, Pos: t.Pos, Beg: p.numItems(t.Block(), lang.Comma)})
-						break
-					}
-				}
-			}
-			ops = append(ops, scanner.Token{Str: "call", Id: lang.Call, Pos: t.Pos})
-		}
-		if lops, lout := len(ops), len(out); lops > 0 && vl > lops {
-			op := ops[lops-1]
-			ops = ops[:lops-1]
-			// Reorder tokens according to operator precedence rules.
-			if p.precedence(out[lout-2]) > p.precedence(op) {
-				op, out[lout-1], out[lout-2] = out[lout-2], op, out[lout-1]
-				if p.precedence(out[lout-3]) > p.precedence(out[lout-1]) {
-					out[lout-1], out[lout-2], out[lout-3] = out[lout-3], out[lout-1], out[lout-2]
-				}
-			}
-			out = append(out, op)
-			vl--
-		}
-	}
-	out = append(out, ops...) // TODO: verify that ops should be added in this order.
-
-	log.Println("ParseExpr out:", out, "vl:", vl, "ops:", ops)
-	// The tokens are now properly ordered, process nested blocks.
-	for i := len(out) - 1; i >= 0; i-- {
-		t := out[i]
-		var toks Tokens
-		switch t.Id {
-		case lang.ParenBlock, lang.BracketBlock:
-			if toks, err = p.ParseExprStr(t.Block()); err != nil {
-				return out, err
-			}
-		default:
-			continue
-		}
-
-		// replace block token by its parsed result.
-		log.Println("toks:", toks)
-		out2 := append(Tokens{}, out[:i]...)
-		out2 = append(out2, toks...)
-		out = append(out2, out[i+1:]...)
-	}
-	log.Println("Final out:", out)
-	return out, err
-}
-
-func (p *Parser) ParseExprStr(s string) (tokens Tokens, err error) {
-	if tokens, err = p.Scan(s, false); err != nil {
-		return
-	}
-	var result Tokens
-	for _, sub := range tokens.Split(lang.Comma) {
-		toks, err := p.ParseExpr(sub)
-		if err != nil {
-			return result, err
-		}
-		result = append(toks, result...)
-	}
-	return result, err
-}
-
 func (p *Parser) numItems(s string, sep lang.TokenId) int {
 	tokens, err := p.Scan(s, false)
 	if err != nil {
-- 
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