pat.rs 6.0 KB

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  1. use super::algorithm::Printer;
  2. use super::iter::IterDelimited;
  3. use super::INDENT;
  4. use proc_macro2::TokenStream;
  5. use syn::{
  6. FieldPat, Pat, PatBox, PatIdent, PatLit, PatMacro, PatOr, PatPath, PatRange, PatReference,
  7. PatRest, PatSlice, PatStruct, PatTuple, PatTupleStruct, PatType, PatWild, RangeLimits,
  8. };
  9. impl Printer {
  10. pub fn pat(&mut self, pat: &Pat) {
  11. match pat {
  12. Pat::Box(pat) => self.pat_box(pat),
  13. Pat::Ident(pat) => self.pat_ident(pat),
  14. Pat::Lit(pat) => self.pat_lit(pat),
  15. Pat::Macro(pat) => self.pat_macro(pat),
  16. Pat::Or(pat) => self.pat_or(pat),
  17. Pat::Path(pat) => self.pat_path(pat),
  18. Pat::Range(pat) => self.pat_range(pat),
  19. Pat::Reference(pat) => self.pat_reference(pat),
  20. Pat::Rest(pat) => self.pat_rest(pat),
  21. Pat::Slice(pat) => self.pat_slice(pat),
  22. Pat::Struct(pat) => self.pat_struct(pat),
  23. Pat::Tuple(pat) => self.pat_tuple(pat),
  24. Pat::TupleStruct(pat) => self.pat_tuple_struct(pat),
  25. Pat::Type(pat) => self.pat_type(pat),
  26. Pat::Verbatim(pat) => self.pat_verbatim(pat),
  27. Pat::Wild(pat) => self.pat_wild(pat),
  28. #[cfg_attr(all(test, exhaustive), deny(non_exhaustive_omitted_patterns))]
  29. _ => unimplemented!("unknown Pat"),
  30. }
  31. }
  32. fn pat_box(&mut self, pat: &PatBox) {
  33. self.outer_attrs(&pat.attrs);
  34. self.word("box ");
  35. self.pat(&pat.pat);
  36. }
  37. fn pat_ident(&mut self, pat: &PatIdent) {
  38. self.outer_attrs(&pat.attrs);
  39. if pat.by_ref.is_some() {
  40. self.word("ref ");
  41. }
  42. if pat.mutability.is_some() {
  43. self.word("mut ");
  44. }
  45. self.ident(&pat.ident);
  46. if let Some((_at_token, subpat)) = &pat.subpat {
  47. self.word(" @ ");
  48. self.pat(subpat);
  49. }
  50. }
  51. fn pat_lit(&mut self, pat: &PatLit) {
  52. self.outer_attrs(&pat.attrs);
  53. self.expr(&pat.expr);
  54. }
  55. fn pat_macro(&mut self, pat: &PatMacro) {
  56. self.outer_attrs(&pat.attrs);
  57. self.mac(&pat.mac, None);
  58. }
  59. fn pat_or(&mut self, pat: &PatOr) {
  60. self.outer_attrs(&pat.attrs);
  61. let mut consistent_break = false;
  62. for case in &pat.cases {
  63. match case {
  64. Pat::Lit(_) | Pat::Wild(_) => {}
  65. _ => {
  66. consistent_break = true;
  67. break;
  68. }
  69. }
  70. }
  71. if consistent_break {
  72. self.cbox(0);
  73. } else {
  74. self.ibox(0);
  75. }
  76. for case in pat.cases.iter().delimited() {
  77. if !case.is_first {
  78. self.space();
  79. self.word("| ");
  80. }
  81. self.pat(&case);
  82. }
  83. self.end();
  84. }
  85. fn pat_path(&mut self, pat: &PatPath) {
  86. self.outer_attrs(&pat.attrs);
  87. self.qpath(&pat.qself, &pat.path);
  88. }
  89. fn pat_range(&mut self, pat: &PatRange) {
  90. self.outer_attrs(&pat.attrs);
  91. self.expr(&pat.lo);
  92. match &pat.limits {
  93. RangeLimits::HalfOpen(_) => self.word(".."),
  94. RangeLimits::Closed(_) => self.word("..="),
  95. }
  96. self.expr(&pat.hi);
  97. }
  98. fn pat_reference(&mut self, pat: &PatReference) {
  99. self.outer_attrs(&pat.attrs);
  100. self.word("&");
  101. if pat.mutability.is_some() {
  102. self.word("mut ");
  103. }
  104. self.pat(&pat.pat);
  105. }
  106. fn pat_rest(&mut self, pat: &PatRest) {
  107. self.outer_attrs(&pat.attrs);
  108. self.word("..");
  109. }
  110. fn pat_slice(&mut self, pat: &PatSlice) {
  111. self.outer_attrs(&pat.attrs);
  112. self.word("[");
  113. for elem in pat.elems.iter().delimited() {
  114. self.pat(&elem);
  115. self.trailing_comma(elem.is_last);
  116. }
  117. self.word("]");
  118. }
  119. fn pat_struct(&mut self, pat: &PatStruct) {
  120. self.outer_attrs(&pat.attrs);
  121. self.cbox(INDENT);
  122. self.path(&pat.path);
  123. self.word(" {");
  124. self.space_if_nonempty();
  125. for field in pat.fields.iter().delimited() {
  126. self.field_pat(&field);
  127. self.trailing_comma_or_space(field.is_last && pat.dot2_token.is_none());
  128. }
  129. if pat.dot2_token.is_some() {
  130. self.word("..");
  131. self.space();
  132. }
  133. self.offset(-INDENT);
  134. self.end();
  135. self.word("}");
  136. }
  137. fn pat_tuple(&mut self, pat: &PatTuple) {
  138. self.outer_attrs(&pat.attrs);
  139. self.word("(");
  140. self.cbox(INDENT);
  141. self.zerobreak();
  142. for elem in pat.elems.iter().delimited() {
  143. self.pat(&elem);
  144. if pat.elems.len() == 1 {
  145. if pat.elems.trailing_punct() {
  146. self.word(",");
  147. }
  148. self.zerobreak();
  149. } else {
  150. self.trailing_comma(elem.is_last);
  151. }
  152. }
  153. self.offset(-INDENT);
  154. self.end();
  155. self.word(")");
  156. }
  157. fn pat_tuple_struct(&mut self, pat: &PatTupleStruct) {
  158. self.outer_attrs(&pat.attrs);
  159. self.path(&pat.path);
  160. self.word("(");
  161. self.cbox(INDENT);
  162. self.zerobreak();
  163. for elem in pat.pat.elems.iter().delimited() {
  164. self.pat(&elem);
  165. self.trailing_comma(elem.is_last);
  166. }
  167. self.offset(-INDENT);
  168. self.end();
  169. self.word(")");
  170. }
  171. pub fn pat_type(&mut self, pat: &PatType) {
  172. self.outer_attrs(&pat.attrs);
  173. self.pat(&pat.pat);
  174. self.word(": ");
  175. self.ty(&pat.ty);
  176. }
  177. fn pat_verbatim(&mut self, pat: &TokenStream) {
  178. unimplemented!("Pat::Verbatim `{}`", pat);
  179. }
  180. fn pat_wild(&mut self, pat: &PatWild) {
  181. self.outer_attrs(&pat.attrs);
  182. self.word("_");
  183. }
  184. fn field_pat(&mut self, field_pat: &FieldPat) {
  185. self.outer_attrs(&field_pat.attrs);
  186. if field_pat.colon_token.is_some() {
  187. self.member(&field_pat.member);
  188. self.word(": ");
  189. }
  190. self.pat(&field_pat.pat);
  191. }
  192. }