Lisp Macros with Clojure

The main feature of Clojure and other lisps that jump out to most people is all those parentheses. In this workshop we’ll put them to good use by exploring what they enable – sophisticated macros for compile-time programming. We’ll introduce the the basic concepts of lisp macros, Clojure’s tools for creating them, and work through a series of increasingly sophisticated exercises, building macro-writing skills and learning best practices for when, and when not, to use them.

Transcript

1. Drew Colthorp www.atomicobject.com Clojure Macros https://github.com/dcolthorp/lj-macro-workspace
2. experience
3. homoiconicity
6. Extensible Data Notation
7. Forms
12. quote
22. eval
26. funhouse
27. extra credit
28. funhouse extra credit Useful functions: first, rest, cons, quote. Useful functions: map
29. funhouse solutions
30. funhouse solutions
31. macros
32. clojure execution read macro expansion analysis/emission evaluation
33. clojure execution read macro expansion analysis/emission evaluation
34. clojure execution read macro expansion analysis/emission evaluation
35. clojure execution read macro expansion analysis/emission evaluation
36. clojure execution read macro expansion analysis/emission evaluation
37. a language of macros
38. a language of macros
39. a language of macros
40. a language of macros
41. debug macro
42. debug macro
43. debug macro
44. debug macro
45. debug macro
46. debug macro
47. debug macro
48. debug macro
49. debug macro
50. debug macro
51. debug macro
52. debug macro
53. debug macro
54. funhouse macros in-funhouse do-funhouse use: cons, map
55. funhouse solutions
56. funhouse solutions
57. funhouse solutions
58. syntax-quote
59. syntax-quote
60. syntax-quote
61. syntax-quote
62. syntax-quote
63. syntax-quote
64. qualified symbols
65. qualified symbols
66. qualified symbols
67. qualified symbols
68. qualified symbols read macro expansion analysis/emission evaluation
69. qualified symbols
70. qualified symbols
71. qualified symbols
72. variable capture
73. variable capture
74. variable capture
75. variable capture
76. variable capture
77. variable capture
78. variable capture
79. variable capture
80. variable capture
81. variable capture
82. gensyms
83. gensyms
84. gensyms
85. gensyms
86. gensyms
87. gensyms
88. gensyms
89. gensyms
90. gensyms
91. syntax-quote: how to
92. syntax-quote: how to
93. syntax-quote: how to
94. syntax-quote: how to
95. syntax-quote: how to
96. syntax-quote: how to
97. syntax-quote: how to
98. syntax-quote: how to
99. syntax-quote: how to
100. de-debug Hints: Syntax-quote everything and unquote macro arguments. Don’t use “list” at all.
101. and-1 and-1 takes two arguments. The second argument short-circuits. and returns the value of the last evaluated expression.
102. multiple execution
105. debug
106. and-1
107. macro tradeoffs
108. less transparent
109. not functions
110. not generally composable
111. snowflakes
112. macros are good for • transforming code – like debug or -> • flow control – like and or twice • binding variables • high performance abstraction
113. high-performance abstraction
115. macros using functions
118. pre-str
119. stringify-static useful functions: map, some-fn, keyword?, string?, number? extra credit: coalesce adjacent output strings into one
120. pre-str solution
121. pre-str solution
122. recursive macros
124. and-*
125. and-* solution
126. and-* solution
127. code walking
128. clojure.walk
129. clojure.walk
130. industrial funhouse
131. industrial funhouse
132. nested syntax-quote
133. macro-writing macros
134. macro-writing macros
135. macro-writing macros
136. deflet
137. deflet
138. deflet
139. macrolet
140. reloop
141. reloop useful: gensym, loop, partition
142. reloop
143. reloop
144. symbol-macrolet
145. lazy deflet
146. Extra
147. levels of quotation