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#include <stdio.h>
#include <iostream>
#include <vector>
#include <map>
#include "util.h"
#include "parser.h"
#include "tokenize.h"
// Extended BEDMAS precedence order
int precedence(Node tok) {
std::string v = tok.val;
if (v == ".") return -1;
else if (v == "!" || v == "not") return 1;
else if (v=="^" || v == "**") return 2;
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else if (v=="*" || v=="/" || v=="%") return 3;
else if (v=="+" || v=="-") return 4;
else if (v=="<" || v==">" || v=="<=" || v==">=") return 5;
else if (v=="&" || v=="|" || v=="xor" || v=="==" || v == "!=") return 6;
else if (v=="&&" || v=="and") return 7;
else if (v=="||" || v=="or") return 8;
else if (v=="=") return 10;
else if (v=="+=" || v=="-=" || v=="*=" || v=="/=" || v=="%=") return 10;
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else if (v==":" || v == "::") return 11;
else return 0;
}
// Token classification for shunting-yard purposes
int toktype(Node tok) {
if (tok.type == ASTNODE) return COMPOUND;
std::string v = tok.val;
if (v == "(" || v == "[" || v == "{") return LPAREN;
else if (v == ")" || v == "]" || v == "}") return RPAREN;
else if (v == ",") return COMMA;
else if (v == "!" || v == "~" || v == "not") return UNARY_OP;
else if (precedence(tok) > 0) return BINARY_OP;
else if (precedence(tok) < 0) return TOKEN_SPLITTER;
if (tok.val[0] != '"' && tok.val[0] != '\'') {
for (unsigned i = 0; i < tok.val.length(); i++) {
if (chartype(tok.val[i]) == SYMB) {
err("Invalid symbol: "+tok.val, tok.metadata);
}
}
}
return ALPHANUM;
}
// Converts to reverse polish notation
std::vector<Node> shuntingYard(std::vector<Node> tokens) {
std::vector<Node> iq;
for (int i = tokens.size() - 1; i >= 0; i--) {
iq.push_back(tokens[i]);
}
std::vector<Node> oq;
std::vector<Node> stack;
Node prev, tok;
int prevtyp = 0, toktyp = 0;
while (iq.size()) {
prev = tok;
prevtyp = toktyp;
tok = iq.back();
toktyp = toktype(tok);
iq.pop_back();
// Alphanumerics go straight to output queue
if (toktyp == ALPHANUM) {
oq.push_back(tok);
}
// Left parens go on stack and output queue
else if (toktyp == LPAREN) {
while (stack.size() && toktype(stack.back()) == TOKEN_SPLITTER) {
oq.push_back(stack.back());
stack.pop_back();
}
if (prevtyp != ALPHANUM && prevtyp != RPAREN) {
oq.push_back(token("id", tok.metadata));
}
stack.push_back(tok);
oq.push_back(tok);
}
// If rparen, keep moving from stack to output queue until lparen
else if (toktyp == RPAREN) {
while (stack.size() && toktype(stack.back()) != LPAREN) {
oq.push_back(stack.back());
stack.pop_back();
}
if (stack.size()) {
stack.pop_back();
}
oq.push_back(tok);
}
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else if (toktyp == UNARY_OP) {
stack.push_back(tok);
}
// If token splitter, just push it to the stack
else if (toktyp == TOKEN_SPLITTER) {
while (stack.size() && toktype(stack.back()) == TOKEN_SPLITTER) {
oq.push_back(stack.back());
stack.pop_back();
}
stack.push_back(tok);
}
// If binary op, keep popping from stack while higher bedmas precedence
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else if (toktyp == BINARY_OP) {
if (tok.val == "-" && prevtyp != ALPHANUM && prevtyp != RPAREN) {
stack.push_back(tok);
oq.push_back(token("0", tok.metadata));
}
else {
int prec = precedence(tok);
while (stack.size()
&& (toktype(stack.back()) == BINARY_OP
|| toktype(stack.back()) == UNARY_OP
|| toktype(stack.back()) == TOKEN_SPLITTER)
&& precedence(stack.back()) <= prec) {
oq.push_back(stack.back());
stack.pop_back();
}
stack.push_back(tok);
}
}
// Comma means finish evaluating the argument
else if (toktyp == COMMA) {
while (stack.size() && toktype(stack.back()) != LPAREN) {
oq.push_back(stack.back());
stack.pop_back();
}
}
}
while (stack.size()) {
oq.push_back(stack.back());
stack.pop_back();
}
return oq;
}
// Converts reverse polish notation into tree
Node treefy(std::vector<Node> stream) {
std::vector<Node> iq;
for (int i = stream.size() -1; i >= 0; i--) {
iq.push_back(stream[i]);
}
std::vector<Node> oq;
while (iq.size()) {
Node tok = iq.back();
iq.pop_back();
int typ = toktype(tok);
// If unary, take node off end of oq and wrap it with the operator
// If binary, do the same with two nodes
if (typ == UNARY_OP || typ == BINARY_OP || typ == TOKEN_SPLITTER) {
std::vector<Node> args;
int rounds = (typ == UNARY_OP) ? 1 : 2;
for (int i = 0; i < rounds; i++) {
if (oq.size() == 0) {
err("Line malformed, not enough args for "+tok.val,
tok.metadata);
}
args.push_back(oq.back());
oq.pop_back();
}
std::vector<Node> args2;
while (args.size()) {
args2.push_back(args.back());
args.pop_back();
}
oq.push_back(astnode(tok.val, args2, tok.metadata));
}
// If rparen, keep grabbing until we get to an lparen
else if (typ == RPAREN) {
std::vector<Node> args;
while (1) {
if (toktype(oq.back()) == LPAREN) break;
args.push_back(oq.back());
oq.pop_back();
if (!oq.size()) err("Bracket without matching", tok.metadata);
}
oq.pop_back();
args.push_back(oq.back());
oq.pop_back();
// We represent a[b] as (access a b)
if (tok.val == "]")
args.push_back(token("access", tok.metadata));
if (args.back().type == ASTNODE)
args.push_back(token("fun", tok.metadata));
std::string fun = args.back().val;
args.pop_back();
// We represent [1,2,3] as (array_lit 1 2 3)
if (fun == "access" && args.size() && args.back().val == "id") {
fun = "array_lit";
args.pop_back();
}
std::vector<Node> args2;
while (args.size()) {
args2.push_back(args.back());
args.pop_back();
}
// When evaluating 2 + (3 * 5), the shunting yard algo turns that
// into 2 ( id 3 5 * ) +, effectively putting "id" as a dummy
// function where the algo was expecting a function to call the
// thing inside the brackets. This reverses that step
if (fun == "id" && args2.size() == 1) {
oq.push_back(args2[0]);
}
else {
oq.push_back(astnode(fun, args2, tok.metadata));
}
}
else oq.push_back(tok);
// This is messy, but has to be done. Import/inset other files here
std::string v = oq.back().val;
if ((v == "inset" || v == "import" || v == "create")
&& oq.back().args.size() == 1
&& oq.back().args[0].type == TOKEN) {
int lastSlashPos = tok.metadata.file.rfind("/");
std::string root;
if (lastSlashPos >= 0)
root = tok.metadata.file.substr(0, lastSlashPos) + "/";
else
root = "";
std::string filename = oq.back().args[0].val;
filename = filename.substr(1, filename.length() - 2);
if (!exists(root + filename))
err("File does not exist: "+root + filename, tok.metadata);
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if (v == "inset") {
oq.pop_back();
oq.push_back(parseSerpent(root + filename));
}
else {
oq.back().args.pop_back();
oq.back().args.push_back(
asn("outer", parseSerpent(root + filename), tok.metadata));
}
}
//Useful for debugging
//for (int i = 0; i < oq.size(); i++) {
// std::cerr << printSimple(oq[i]) << " ";
//}
//std::cerr << " <-\n";
}
// Output must have one argument
if (oq.size() == 0) {
err("Output blank", Metadata());
}
else if (oq.size() > 1) {
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return asn("multi", oq, oq[0].metadata);
}
return oq[0];
}
// Parses one line of serpent
Node parseSerpentTokenStream(std::vector<Node> s) {
return treefy(shuntingYard(s));
}
// Count spaces at beginning of line
int spaceCount(std::string s) {
unsigned pos = 0;
while (pos < s.length() && (s[pos] == ' ' || s[pos] == '\t'))
pos++;
return pos;
}
// Is this a command that takes an argument on the same line?
bool bodied(std::string tok) {
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return tok == "if" || tok == "elif" || tok == "while"
|| tok == "with" || tok == "def" || tok == "extern"
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|| tok == "data" || tok == "assert" || tok == "return"
|| tok == "fun" || tok == "scope" || tok == "macro"
|| tok == "type";
}
// Are the two commands meant to continue each other?
bool bodiedContinued(std::string prev, std::string tok) {
return (prev == "if" && tok == "elif")
|| (prev == "elif" && tok == "else")
|| (prev == "elif" && tok == "elif")
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|| (prev == "if" && tok == "else");
}
// Is a line of code empty?
bool isLineEmpty(std::string line) {
std::vector<Node> tokens = tokenize(line);
if (!tokens.size() || tokens[0].val == "#" || tokens[0].val == "//")
return true;
return false;
}
// Parse lines of serpent (helper function)
Node parseLines(std::vector<std::string> lines, Metadata metadata, int sp) {
std::vector<Node> o;
int origLine = metadata.ln;
unsigned i = 0;
while (i < lines.size()) {
metadata.ln = origLine + i;
std::string main = lines[i];
if (isLineEmpty(main)) {
i += 1;
continue;
}
int spaces = spaceCount(main);
if (spaces != sp) {
err("Indent mismatch", metadata);
}
// Tokenize current line
std::vector<Node> tokens = tokenize(main.substr(sp), metadata);
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// Remove comments
std::vector<Node> tokens2;
for (unsigned j = 0; j < tokens.size(); j++) {
if (tokens[j].val == "#" || tokens[j].val == "//") break;
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tokens2.push_back(tokens[j]);
}
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bool expectingChildBlock = false;
if (tokens2.size() > 0 && tokens2.back().val == ":") {
tokens2.pop_back();
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expectingChildBlock = true;
}
// Parse current line
Node out = parseSerpentTokenStream(tokens2);
// Parse child block
int childIndent = 999999;
std::vector<std::string> childBlock;
while (1) {
i++;
if (i >= lines.size())
break;
bool ile = isLineEmpty(lines[i]);
if (!ile) {
int spaces = spaceCount(lines[i]);
if (spaces <= sp) break;
childBlock.push_back(lines[i]);
if (spaces < childIndent) childIndent = spaces;
}
else childBlock.push_back("");
}
// Child block empty?
bool cbe = true;
for (unsigned i = 0; i < childBlock.size(); i++) {
if (childBlock[i].length() > 0) { cbe = false; break; }
}
// Add child block to AST
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if (expectingChildBlock) {
if (cbe)
err("Expected indented child block!", out.metadata);
out.type = ASTNODE;
metadata.ln += 1;
out.args.push_back(parseLines(childBlock, metadata, childIndent));
metadata.ln -= 1;
}
else if (!cbe)
err("Did not expect indented child block!", out.metadata);
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else if (out.args.size() && out.args[out.args.size() - 1].val == ":") {
Node n = out.args[out.args.size() - 1];
out.args.pop_back();
out.args.push_back(n.args[0]);
out.args.push_back(n.args[1]);
}
// Bring back if / elif into AST
if (bodied(tokens[0].val)) {
if (out.val != "multi") {
// token not being used in bodied form
}
else if (out.args[0].val == "id")
out = astnode(tokens[0].val, out.args[1].args, out.metadata);
else if (out.args[0].type == TOKEN) {
std::vector<Node> out2;
for (unsigned i = 1; i < out.args.size(); i++)
out2.push_back(out.args[i]);
out = astnode(tokens[0].val, out2, out.metadata);
}
else
out = astnode("fun", out.args, out.metadata);
}
// Multi not supported
if (out.val == "multi")
err("Multiple expressions or unclosed bracket", out.metadata);
// Convert top-level colon expressions into non-colon expressions;
// makes if statements and the like equivalent indented or not
//if (out.val == ":" && out.args[0].type == TOKEN)
// out = asn(out.args[0].val, out.args[1], out.metadata);
//if (bodied(tokens[0].val) && out.args[0].val == ":")
// out = asn(tokens[0].val, out.args[0].args);
if (o.size() == 0 || o.back().type == TOKEN) {
o.push_back(out);
continue;
}
// This is a little complicated. Basically, the idea here is to build
// constructions like [if [< x 5] [a] [elif [< x 10] [b] [else [c]]]]
std::vector<Node> u;
u.push_back(o.back());
if (bodiedContinued(o.back().val, out.val)) {
while (1) {
if (!bodiedContinued(u.back().val, out.val)) {
u.pop_back();
break;
}
if (!u.back().args.size()
|| !bodiedContinued(u.back().val, u.back().args.back().val)) {
break;
}
u.push_back(u.back().args.back());
}
u.back().args.push_back(out);
while (u.size() > 1) {
Node v = u.back();
u.pop_back();
u.back().args.pop_back();
u.back().args.push_back(v);
}
o.pop_back();
o.push_back(u[0]);
}
else o.push_back(out);
}
if (o.size() == 1)
return o[0];
else if (o.size())
return astnode("seq", o, o[0].metadata);
else
return astnode("seq", o, Metadata());
}
// Parses serpent code
Node parseSerpent(std::string s) {
std::string input = s;
std::string file = "main";
if (exists(s)) {
file = s;
input = get_file_contents(s);
}
return parseLines(splitLines(input), Metadata(file, 0, 0), 0);
}
using namespace std;