bool check_exp(const node* p, int rr_level)
{
if (!p || p->t == nt_num) return true;
// rrlvl1: 交换率，以下两个判断保证了A+B+C+...+Z这种形式下，只选择A>B>C>...>Z这一种组合
if (rr_level >= 1)
{
if (commulative(p->op))
{
double v1 = p->l_child->val();
double v2 = p->r_child->val();
if (v1 < v2) return false;
if (double_equ(v1, v2) && shape_less(p->l_child, p->r_child)) return false;
}
if (p->l_child->t == nt_op && p->l_child->op == p->op && associative(p->op))
{
double v1 = p->l_child->r_child->val();
double v2 = p->r_child->val();
if (v1 < v2) return false;
if (double_equ(v1, v2) && shape_less(p->l_child->r_child, p->r_child)) return false;
}
}
// rrlvl2: 去除/1和-0。/1可以用*1替换，-0可以用+0替换。
if (rr_level >= 2)
{
if (p->op == L'/' && double_equ(p->r_child->val(), 1)) return false;
if (p->op == L'-' && double_equ(p->r_child->val(), 0)) return false;
}
if (!check_exp(p->l_child, rr_level)) return false;
if (!check_exp(p->r_child, rr_level)) return false;
return true;
}
bool check_bone(const node* p, int rr_level)
{
if (!p || p->t == nt_num) return true;
// '_'是连字符，要求右孩子是数，左孩子是数或者也是个'_'
if (p->op == L'_')
{
if (p->r_child->t == nt_op) return false;
if (p->l_child->t == nt_op && p->l_child->op != L'_') return false;
}
if (rr_level >= 1)
{
// 交换率：规定两个分支的顺序
if (commulative(p->op))
{
// 不可以在这里判断，在check_exp时对满足交换率的左右子树采用了求值的方法：大值在左
// if (shape_less(p->l_child, p->r_child, false)) return false;
}
// 不能出现 A-B+C A/B*C，应该是A+C-B, A*C/B
if (p->l_child->t == nt_op && get_pred(p->op) == get_pred(p->l_child->op))
{
if (p->op < p->l_child->op) return false;
}
// 结合率
// 不能出现 A+(B+C), A+(B-C), A-(B+C), A-(B-C)这样的情况，乘除类似
if (p->r_child->t == nt_op && associative(p->op) && get_pred(p->op) == get_pred(p->r_child->op)) return false;
}
if (!check_bone(p->l_child, rr_level)) return false;
if (!check_bone(p->r_child, rr_level)) return false;
return true;
}
string DocCompiler::generateBinOp(Tree sig, int opcode, Tree arg1, Tree arg2, int priority)
{
string s;
int thisPriority = gBinOpLateqTable[opcode]->fPriority;
/* Priority parenthesis handling. */
string lpar = "";
string rpar = "";
if((thisPriority < priority) || ((thisPriority == priority) && !associative(opcode)))
{
// (a+b)*c or (a/b)/c need parenthesis
lpar = " \\left(";
rpar = "\\right) ";
}
Type t1 = getCertifiedSigType(arg1);
Type t2 = getCertifiedSigType(arg2);
bool intOpDetected = false;
if((t1->nature() == kInt) && (t2->nature() == kInt))
{
intOpDetected = true;
}
string op;
if(!intOpDetected)
{
op = gBinOpLateqTable[opcode]->fName;
}
else
{
switch(opcode)
{
case kAdd:
op = "\\oplus";
gDocNoticeFlagMap["intplus"] = true;
break;
case kSub:
op = "\\ominus";
gDocNoticeFlagMap["intminus"] = true;
break;
case kMul:
op = "\\odot";
gDocNoticeFlagMap["intmult"] = true;
break;
case kDiv:
op = "\\oslash";
gDocNoticeFlagMap["intdiv"] = true;
gDocNoticeFlagMap["intcast"] = true; // "$normalize(int(i/j))$" in the notice.
break;
default:
op = gBinOpLateqTable[opcode]->fName;
break;
}
}
/* LaTeX frac{}{} handling VS general case. */
if((opcode == kDiv) && (!intOpDetected))
{
s = subst("$0\\frac{$1}{$2}$3", lpar, CS(arg1, 0), CS(arg2, 0), rpar);
}
else
{
s = subst("$0$1 $2 $3$4", lpar, CS(arg1, thisPriority), op, CS(arg2, thisPriority), rpar);
}
// if (opcode == kMul) {
// gDocNoticeFlagMap["cdot"] = true;
// }
return generateCacheCode(sig, s);
}