Add whitespace control options: trim_blocks, lstrip_blocks (#116)
diff --git a/include/inja/config.hpp b/include/inja/config.hpp
index 0d571b0..d7f16b9 100644
--- a/include/inja/config.hpp
+++ b/include/inja/config.hpp
@@ -24,6 +24,9 @@
std::string comment_close {"#}"};
std::string open_chars {"#{"};
+ bool trim_blocks {false};
+ bool lstrip_blocks {false};
+
void update_open_chars() {
open_chars = "";
if (open_chars.find(line_statement[0]) == std::string::npos) {
diff --git a/include/inja/environment.hpp b/include/inja/environment.hpp
index a590c5f..b794e36 100644
--- a/include/inja/environment.hpp
+++ b/include/inja/environment.hpp
@@ -77,6 +77,16 @@
m_impl->lexer_config.update_open_chars();
}
+ /// Sets whether to remove the first newline after a block
+ void set_trim_blocks(bool trim_blocks) {
+ m_impl->lexer_config.trim_blocks = trim_blocks;
+ }
+
+ /// Sets whether to strip the spaces and tabs from the start of a line to a block
+ void set_lstrip_blocks(bool lstrip_blocks) {
+ m_impl->lexer_config.lstrip_blocks = lstrip_blocks;
+ }
+
/// Sets the element notation syntax
void set_element_notation(ElementNotation notation) {
m_impl->parser_config.notation = notation;
diff --git a/include/inja/lexer.hpp b/include/inja/lexer.hpp
index 2ef6db0..ebad0f7 100644
--- a/include/inja/lexer.hpp
+++ b/include/inja/lexer.hpp
@@ -59,12 +59,15 @@
// try to match one of the opening sequences, and get the close
nonstd::string_view open_str = m_in.substr(m_pos);
+ bool must_lstrip = false;
if (inja::string_view::starts_with(open_str, m_config.expression_open)) {
m_state = State::ExpressionStart;
} else if (inja::string_view::starts_with(open_str, m_config.statement_open)) {
m_state = State::StatementStart;
+ must_lstrip = m_config.lstrip_blocks;
} else if (inja::string_view::starts_with(open_str, m_config.comment_open)) {
m_state = State::CommentStart;
+ must_lstrip = m_config.lstrip_blocks;
} else if ((m_pos == 0 || m_in[m_pos - 1] == '\n') &&
inja::string_view::starts_with(open_str, m_config.line_statement)) {
m_state = State::LineStart;
@@ -72,8 +75,13 @@
m_pos += 1; // wasn't actually an opening sequence
goto again;
}
- if (m_pos == m_tok_start) goto again; // don't generate empty token
- return make_token(Token::Kind::Text);
+
+ nonstd::string_view text = string_view::slice(m_in, m_tok_start, m_pos);
+ if (must_lstrip)
+ text = clear_final_line_if_whitespace(text);
+
+ if (text.empty()) goto again; // don't generate empty token
+ return Token(Token::Kind::Text, text);
}
case State::ExpressionStart: {
m_state = State::ExpressionBody;
@@ -100,7 +108,7 @@
case State::LineBody:
return scan_body("\n", Token::Kind::LineStatementClose);
case State::StatementBody:
- return scan_body(m_config.statement_close, Token::Kind::StatementClose);
+ return scan_body(m_config.statement_close, Token::Kind::StatementClose, m_config.trim_blocks);
case State::CommentBody: {
// fast-scan to comment close
size_t end = m_in.substr(m_pos).find(m_config.comment_close);
@@ -111,7 +119,10 @@
// return the entire comment in the close token
m_state = State::Text;
m_pos += end + m_config.comment_close.size();
- return make_token(Token::Kind::CommentClose);
+ Token tok = make_token(Token::Kind::CommentClose);
+ if (m_config.trim_blocks)
+ skip_newline();
+ return tok;
}
}
}
@@ -119,7 +130,7 @@
const LexerConfig& get_config() const { return m_config; }
private:
- Token scan_body(nonstd::string_view close, Token::Kind closeKind) {
+ Token scan_body(nonstd::string_view close, Token::Kind closeKind, bool trim = false) {
again:
// skip whitespace (except for \n as it might be a close)
if (m_tok_start >= m_in.size()) return make_token(Token::Kind::Eof);
@@ -133,7 +144,10 @@
if (inja::string_view::starts_with(m_in.substr(m_tok_start), close)) {
m_state = State::Text;
m_pos = m_tok_start + close.size();
- return make_token(closeKind);
+ Token tok = make_token(closeKind);
+ if (trim)
+ skip_newline();
+ return tok;
}
// skip \n
@@ -254,6 +268,34 @@
Token make_token(Token::Kind kind) const {
return Token(kind, string_view::slice(m_in, m_tok_start, m_pos));
}
+
+ void skip_newline() {
+ if (m_pos < m_in.size()) {
+ char ch = m_in[m_pos];
+ if (ch == '\n')
+ m_pos += 1;
+ else if (ch == '\r') {
+ m_pos += 1;
+ if (m_pos < m_in.size() && m_in[m_pos] == '\n')
+ m_pos += 1;
+ }
+ }
+ }
+
+ static nonstd::string_view clear_final_line_if_whitespace(nonstd::string_view text)
+ {
+ nonstd::string_view result = text;
+ while (!result.empty()) {
+ char ch = result.back();
+ if (ch == ' ' || ch == '\t')
+ result.remove_suffix(1);
+ else if (ch == '\n' || ch == '\r')
+ break;
+ else
+ return text;
+ }
+ return result;
+ }
};
}
